Skip to main content
Top
Published in: BMC Cancer 1/2011

Open Access 01-12-2011 | Research article

O6-Methylguanine-DNA methyltransferase protein expression by immunohistochemistry in brain and non-brain systemic tumours: systematic review and meta-analysis of correlation with methylation-specific polymerase chain reaction

Authors: Marta Brell, Javier Ibáñez, Avelina Tortosa

Published in: BMC Cancer | Issue 1/2011

Login to get access

Abstract

Background

The DNA repair protein O6-Methylguanine-DNA methyltransferase (MGMT) confers resistance to alkylating agents. Several methods have been applied to its analysis, with methylation-specific polymerase chain reaction (MSP) the most commonly used for promoter methylation study, while immunohistochemistry (IHC) has become the most frequently used for the detection of MGMT protein expression. Agreement on the best and most reliable technique for evaluating MGMT status remains unsettled. The aim of this study was to perform a systematic review and meta-analysis of the correlation between IHC and MSP.

Methods

A computer-aided search of MEDLINE (1950-October 2009), EBSCO (1966-October 2009) and EMBASE (1974-October 2009) was performed for relevant publications. Studies meeting inclusion criteria were those comparing MGMT protein expression by IHC with MGMT promoter methylation by MSP in the same cohort of patients. Methodological quality was assessed by using the QUADAS and STARD instruments. Previously published guidelines were followed for meta-analysis performance.

Results

Of 254 studies identified as eligible for full-text review, 52 (20.5%) met the inclusion criteria. The review showed that results of MGMT protein expression by IHC are not in close agreement with those obtained with MSP. Moreover, type of tumour (primary brain tumour vs others) was an independent covariate of accuracy estimates in the meta-regression analysis beyond the cut-off value.

Conclusions

Protein expression assessed by IHC alone fails to reflect the promoter methylation status of MGMT. Thus, in attempts at clinical diagnosis the two methods seem to select different groups of patients and should not be used interchangeably.
Appendix
Available only for authorised users
Literature
1.
go back to reference Bae SI, Lee HS, Kim SH, Kim WH: Inactivation of O6-methylguanine-DNA methyltransferase by promoter CpG island hypermethylation in gastric cancers. Br J Cancer. 2002, 86: 1888-1892. 10.1038/sj.bjc.6600372.PubMedPubMedCentral Bae SI, Lee HS, Kim SH, Kim WH: Inactivation of O6-methylguanine-DNA methyltransferase by promoter CpG island hypermethylation in gastric cancers. Br J Cancer. 2002, 86: 1888-1892. 10.1038/sj.bjc.6600372.PubMedPubMedCentral
2.
go back to reference Esteller M, Hamilton SR, Burger PC, Baylin SB, Herman JG: Inactivation of the DNA repair gene O6-methylguanine-DNA methyltransferase by promoter hypermethylation is a common event in primary human neoplasia. Cancer Res. 1999, 59: 793-797.PubMed Esteller M, Hamilton SR, Burger PC, Baylin SB, Herman JG: Inactivation of the DNA repair gene O6-methylguanine-DNA methyltransferase by promoter hypermethylation is a common event in primary human neoplasia. Cancer Res. 1999, 59: 793-797.PubMed
3.
go back to reference Jaeckle KA, Eyre HJ, Townsend JJ, Schulman S, Knudson HM, Belanich M, Yarosh DB, Bearman SI, Giroux DJ, Schold SC: Correlation of tumor O6 methylguanine-DNA methyltransferase levels with survival of malignant astrocytoma patients treated with bis-chloroethylnitrosourea: a Southwest Oncology Group study. J Clin Oncol. 1998, 16: 3310-3315.PubMed Jaeckle KA, Eyre HJ, Townsend JJ, Schulman S, Knudson HM, Belanich M, Yarosh DB, Bearman SI, Giroux DJ, Schold SC: Correlation of tumor O6 methylguanine-DNA methyltransferase levels with survival of malignant astrocytoma patients treated with bis-chloroethylnitrosourea: a Southwest Oncology Group study. J Clin Oncol. 1998, 16: 3310-3315.PubMed
4.
go back to reference Gerson SL: Clinical relevance of MGMT in the treatment of cancer. J Clin Oncol. 2002, 20: 2388-2399. 10.1200/JCO.2002.06.110.PubMed Gerson SL: Clinical relevance of MGMT in the treatment of cancer. J Clin Oncol. 2002, 20: 2388-2399. 10.1200/JCO.2002.06.110.PubMed
5.
go back to reference Jones PA, Laird PW: Cancer epigenetics comes from age. Nat Genet. 1999, 21: 163-167. 10.1038/5947.PubMed Jones PA, Laird PW: Cancer epigenetics comes from age. Nat Genet. 1999, 21: 163-167. 10.1038/5947.PubMed
6.
go back to reference Robertson KD, Jones PA: DNA methylation: past, present and furture directions. Carcinogenesis. 2000, 21: 461-467. 10.1093/carcin/21.3.461.PubMed Robertson KD, Jones PA: DNA methylation: past, present and furture directions. Carcinogenesis. 2000, 21: 461-467. 10.1093/carcin/21.3.461.PubMed
7.
go back to reference Baylin SB, Herman JG: DNA hypermethylation in tumorigenesis: epigenetic joins genetics. Trends Genet. 2000, 16: 168-173. 10.1016/S0168-9525(99)01971-X.PubMed Baylin SB, Herman JG: DNA hypermethylation in tumorigenesis: epigenetic joins genetics. Trends Genet. 2000, 16: 168-173. 10.1016/S0168-9525(99)01971-X.PubMed
8.
go back to reference Esteller M, García-Foncillas J, Andion E, Goodman SN, Hidalgo OF, Vanaclocha V, Baylin SB, Herman JG: Inactivation of the DNA-repair gene MGMT and the clinical response of gliomas to alkylating agents. N Eng J Med. 2000, 343: 1350-1354. 10.1056/NEJM200011093431901. Esteller M, García-Foncillas J, Andion E, Goodman SN, Hidalgo OF, Vanaclocha V, Baylin SB, Herman JG: Inactivation of the DNA-repair gene MGMT and the clinical response of gliomas to alkylating agents. N Eng J Med. 2000, 343: 1350-1354. 10.1056/NEJM200011093431901.
9.
go back to reference Hegi ME, Diserens AC, Gorlia T, Hamou MF, de Tribolet N, Weller M, Kros JM, Hainfellner JA, Mason W, Mariani L, Bromberg JEC, Hau P, Mirimanoff RO, Cairncross JG, Janzer RC, Stupp R: MGMT gene silencing and benefit from Temozolamide in glioblastoma. N Engl J Med. 2005, 352: 997-1003. 10.1056/NEJMoa043331.PubMed Hegi ME, Diserens AC, Gorlia T, Hamou MF, de Tribolet N, Weller M, Kros JM, Hainfellner JA, Mason W, Mariani L, Bromberg JEC, Hau P, Mirimanoff RO, Cairncross JG, Janzer RC, Stupp R: MGMT gene silencing and benefit from Temozolamide in glioblastoma. N Engl J Med. 2005, 352: 997-1003. 10.1056/NEJMoa043331.PubMed
10.
go back to reference Hegi ME, Diserens AC, Godard S, Dietrich PY, Regli L, Ostermann S, Otten P, Van Melle G, de Tribolet N, Strupp R: Clinical trial substantiates the predictive value of O6-Metylguanine-DNA methyltransferase promoter methylation in glioblastoma patients treated with Temozolamide. Clin Cancer Res. 2004, 10: 1871-1874. 10.1158/1078-0432.CCR-03-0384.PubMed Hegi ME, Diserens AC, Godard S, Dietrich PY, Regli L, Ostermann S, Otten P, Van Melle G, de Tribolet N, Strupp R: Clinical trial substantiates the predictive value of O6-Metylguanine-DNA methyltransferase promoter methylation in glioblastoma patients treated with Temozolamide. Clin Cancer Res. 2004, 10: 1871-1874. 10.1158/1078-0432.CCR-03-0384.PubMed
11.
go back to reference Crinière E, Kaloshi G, Laigle-Donadey F, Lejeune J, Auger N, Benouaich-Amiel A, Everhard S, Mokhtari K, Polivka M, Delattre JY, Hoang-Xuan K, Thillet J, Sanson M: MGMT prognostic impact on glioblastoma is dependent on therapeutic modalities. J Neurooncol. 2007, 83: 173-179.PubMed Crinière E, Kaloshi G, Laigle-Donadey F, Lejeune J, Auger N, Benouaich-Amiel A, Everhard S, Mokhtari K, Polivka M, Delattre JY, Hoang-Xuan K, Thillet J, Sanson M: MGMT prognostic impact on glioblastoma is dependent on therapeutic modalities. J Neurooncol. 2007, 83: 173-179.PubMed
12.
go back to reference Everhard S, Kaloshi G, Crinière E, Benouaich-Amiel A, Lejeune J, Marie Y, Sanson M, Kujas M, Mokhtari K, Hoang-Xuan K, Delattre JY, Thillet J: MGMT Methylation: a marker of response to Temozolamide in low-grade gliomas. Ann Neurol. 2006, 60: 740-743. 10.1002/ana.21044.PubMed Everhard S, Kaloshi G, Crinière E, Benouaich-Amiel A, Lejeune J, Marie Y, Sanson M, Kujas M, Mokhtari K, Hoang-Xuan K, Delattre JY, Thillet J: MGMT Methylation: a marker of response to Temozolamide in low-grade gliomas. Ann Neurol. 2006, 60: 740-743. 10.1002/ana.21044.PubMed
13.
go back to reference Kamiryo T, Tada K, Shiraishi S, Shinojima N, Kochi M, Ushio Y: Correlation between promoter hypermethylation of the O6-methylguanine-deoxyribonucleic acid methyltransferase gene and prognosis in patients with high-grade astrocytic tumors treated with surgery, radiotherapy, and 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea-based chemotherapy. Neurosurgery. 2004, 52: 349-357. 10.1227/01.NEU.0000103422.51382.99. Kamiryo T, Tada K, Shiraishi S, Shinojima N, Kochi M, Ushio Y: Correlation between promoter hypermethylation of the O6-methylguanine-deoxyribonucleic acid methyltransferase gene and prognosis in patients with high-grade astrocytic tumors treated with surgery, radiotherapy, and 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea-based chemotherapy. Neurosurgery. 2004, 52: 349-357. 10.1227/01.NEU.0000103422.51382.99.
14.
go back to reference Watanabe T, Katayama Y, Komine C, Yoshino A, Ogino A, Ohta T, Fukushima T: O6-Methylguanine-DNA methyltransferase methylation and TP53 mutation in malignant astrocytomas and their relationships with clinical course. Int J Cancer. 2005, 113: 581-587. 10.1002/ijc.20625.PubMed Watanabe T, Katayama Y, Komine C, Yoshino A, Ogino A, Ohta T, Fukushima T: O6-Methylguanine-DNA methyltransferase methylation and TP53 mutation in malignant astrocytomas and their relationships with clinical course. Int J Cancer. 2005, 113: 581-587. 10.1002/ijc.20625.PubMed
15.
go back to reference Gorlia T, van den Bent MJ, Hegi ME, Mirimanoff RO, Weller M, Cairncross JG, Eisenhauer E, Belanger K, Brandes AA, Allgeier A, Lacombe D, Stupp R: Nomograms for predicting survival of patients with newly diagnosed glioblastoma: prognostic factor analysis of EORTC and NCIC trial 26981-22981/CE.3. Lancet Oncol. 2008, 9: 29-38. 10.1016/S1470-2045(07)70384-4.PubMed Gorlia T, van den Bent MJ, Hegi ME, Mirimanoff RO, Weller M, Cairncross JG, Eisenhauer E, Belanger K, Brandes AA, Allgeier A, Lacombe D, Stupp R: Nomograms for predicting survival of patients with newly diagnosed glioblastoma: prognostic factor analysis of EORTC and NCIC trial 26981-22981/CE.3. Lancet Oncol. 2008, 9: 29-38. 10.1016/S1470-2045(07)70384-4.PubMed
16.
go back to reference Sadones J, Michotte A, Veld P, Chaskis C, Sciot R, Menten J, Joossens EJ, Strauven T, D'Hondt LA, Sartenaer D, Califice SF, Bierau K, Svensson C, De Greve J, Neyns B: MGMT promoter hypermethylation correlates with a survival benefit from temozolomide in patients with recurrent anaplastic astrocytoma but not glioblastoma. Eur J Cancer. 2009, 45: 146-153. 10.1016/j.ejca.2008.09.002.PubMed Sadones J, Michotte A, Veld P, Chaskis C, Sciot R, Menten J, Joossens EJ, Strauven T, D'Hondt LA, Sartenaer D, Califice SF, Bierau K, Svensson C, De Greve J, Neyns B: MGMT promoter hypermethylation correlates with a survival benefit from temozolomide in patients with recurrent anaplastic astrocytoma but not glioblastoma. Eur J Cancer. 2009, 45: 146-153. 10.1016/j.ejca.2008.09.002.PubMed
17.
go back to reference Shaw RJ, Hall GL, Lowe D, Liloglou T, Field JK, Sloan P, Risk JM: The role of pyrosequencing in head and neck cancer epigenetics: correlation of quantitative methylation data with gene expression. Arch Otolaryngol Head Neck Surg. 2008, 134: 251-256. 10.1001/archoto.2007.50.PubMed Shaw RJ, Hall GL, Lowe D, Liloglou T, Field JK, Sloan P, Risk JM: The role of pyrosequencing in head and neck cancer epigenetics: correlation of quantitative methylation data with gene expression. Arch Otolaryngol Head Neck Surg. 2008, 134: 251-256. 10.1001/archoto.2007.50.PubMed
18.
go back to reference Preusser M, Elezi L, Hainfellner JA: Reliability and reproducibility of PCR-based testing of O6-methylguanine-DNA methyltransferase gene (MGMT) promoter methylation status in formalin-fixed and paraffin-embedded neurosurgical biopsy specimens. Clin Neuropathol. 2008, 27: 388-390.PubMed Preusser M, Elezi L, Hainfellner JA: Reliability and reproducibility of PCR-based testing of O6-methylguanine-DNA methyltransferase gene (MGMT) promoter methylation status in formalin-fixed and paraffin-embedded neurosurgical biopsy specimens. Clin Neuropathol. 2008, 27: 388-390.PubMed
19.
go back to reference Yip S, Iafrate AJ, Louis DN: Molecular diagnostic testing in malignant gliomas: a practical update on predictive markers. J Neuropathol Exp Neurol. 2008, 67: 1-15. 10.1097/nen.0b013e31815f65fb.PubMed Yip S, Iafrate AJ, Louis DN: Molecular diagnostic testing in malignant gliomas: a practical update on predictive markers. J Neuropathol Exp Neurol. 2008, 67: 1-15. 10.1097/nen.0b013e31815f65fb.PubMed
20.
go back to reference Preusser M, Charles JR, Felsberg J, Reifenberger G, Hamou MF, Diserens AC, Stupp R, Gorlia T, Marosi C, Heinzl H, Hainfellner JA, Hegi M: Anti-O6-methylguanine-methyltransferase (MGMT) immunohistochemistry in glioblastoma multiforme: observer variability and lack of association with patient survival impede its use as clinical biomarker. Brain Pathol. 2008, 18: 520-532.PubMed Preusser M, Charles JR, Felsberg J, Reifenberger G, Hamou MF, Diserens AC, Stupp R, Gorlia T, Marosi C, Heinzl H, Hainfellner JA, Hegi M: Anti-O6-methylguanine-methyltransferase (MGMT) immunohistochemistry in glioblastoma multiforme: observer variability and lack of association with patient survival impede its use as clinical biomarker. Brain Pathol. 2008, 18: 520-532.PubMed
21.
go back to reference Andersson U, Malmer B, Bergenheim AT, Brännström T, Henriksson R: Heterogeneity in the expression of markers for drug resistance in brain tumors. Clin Neuropathol. 2004, 23: 21-27.PubMed Andersson U, Malmer B, Bergenheim AT, Brännström T, Henriksson R: Heterogeneity in the expression of markers for drug resistance in brain tumors. Clin Neuropathol. 2004, 23: 21-27.PubMed
22.
go back to reference Capper D, Mittelbronn M, Meyermann R, Schittenhelm J: Pitfalls in the assessment of MGMT expression and its correlation with survival in diffuse astrocytomas: proposal of feasible immunohistochemical approach. Acta Neuropathol. 2008, 115: 249-259. 10.1007/s00401-007-0310-x.PubMed Capper D, Mittelbronn M, Meyermann R, Schittenhelm J: Pitfalls in the assessment of MGMT expression and its correlation with survival in diffuse astrocytomas: proposal of feasible immunohistochemical approach. Acta Neuropathol. 2008, 115: 249-259. 10.1007/s00401-007-0310-x.PubMed
23.
go back to reference Chinot OL, Barrie M, Fuentes S, Eudes N, Lancelot S, Metellus P, Muracciole X, Braguer D, Ouafik L, Martin PM, Dufour H, Figarella-Branger D: Correlation between O6-methylguanine-DNA methyltransferase and survival in inoperable newly diagnosed glioblastoma patients treated with neoadjuvant temozolomide. J Clin Oncol. 2007, 25: 1470-1475. 10.1200/JCO.2006.07.4807.PubMed Chinot OL, Barrie M, Fuentes S, Eudes N, Lancelot S, Metellus P, Muracciole X, Braguer D, Ouafik L, Martin PM, Dufour H, Figarella-Branger D: Correlation between O6-methylguanine-DNA methyltransferase and survival in inoperable newly diagnosed glioblastoma patients treated with neoadjuvant temozolomide. J Clin Oncol. 2007, 25: 1470-1475. 10.1200/JCO.2006.07.4807.PubMed
24.
go back to reference Friedman HS, McLendon RE, Kerby T, Dugan M, Bigner SH, Henry AJ, Ashley DM, Krischer J, Lovell S, Rasheed K, Marchev F, Seman AJ, Cokgor I, Rich J, Stewart E, Colvin OM, Provenzale JM, Bigner DD, Haglund MM, Friedman AH, Modrich PL: DNA Mismatch repair and O6-alkyguanine-DNA alkyltransferase analysis and response to Temodal in newly diagnosed malignant glioma. J Clin Oncol. 1998, 16: 3851-3857.PubMed Friedman HS, McLendon RE, Kerby T, Dugan M, Bigner SH, Henry AJ, Ashley DM, Krischer J, Lovell S, Rasheed K, Marchev F, Seman AJ, Cokgor I, Rich J, Stewart E, Colvin OM, Provenzale JM, Bigner DD, Haglund MM, Friedman AH, Modrich PL: DNA Mismatch repair and O6-alkyguanine-DNA alkyltransferase analysis and response to Temodal in newly diagnosed malignant glioma. J Clin Oncol. 1998, 16: 3851-3857.PubMed
25.
go back to reference Idbaih A, Omuro A, Ducray F, Hoang-Xuan K: Molecular genetic markers as predictors of response to chemotherapy in gliomas. Curr Opin Oncol. 2007, 19: 606-611. 10.1097/CCO.0b013e3282f075f3.PubMed Idbaih A, Omuro A, Ducray F, Hoang-Xuan K: Molecular genetic markers as predictors of response to chemotherapy in gliomas. Curr Opin Oncol. 2007, 19: 606-611. 10.1097/CCO.0b013e3282f075f3.PubMed
26.
go back to reference Jeuken JW, Cornelissen SJ, Vriezen M, Dekkers MM, Errami A, Sijben A, Boots-Sprenger SH, Wesseling P: MS-MLPA: an attractive alternative laboratory assay for robust, reliable, and semiquantitative detection of MGMT promoter hypermethylation in gliomas. Lab Invest. 2007, 87: 1055-1065. 10.1038/labinvest.3700664.PubMed Jeuken JW, Cornelissen SJ, Vriezen M, Dekkers MM, Errami A, Sijben A, Boots-Sprenger SH, Wesseling P: MS-MLPA: an attractive alternative laboratory assay for robust, reliable, and semiquantitative detection of MGMT promoter hypermethylation in gliomas. Lab Invest. 2007, 87: 1055-1065. 10.1038/labinvest.3700664.PubMed
27.
go back to reference McLendon RE, Cleveland L, Pegram C, Bigner SH, Bigner DD, Friedman HS: Immunohistochemical detection of the DNA repair enzyme O6-methylguanine-DNA methyltransferase in formalin-fixed, paraffin-embedded astrocytomas. Lab Invest. 1998, 78: 643-644.PubMed McLendon RE, Cleveland L, Pegram C, Bigner SH, Bigner DD, Friedman HS: Immunohistochemical detection of the DNA repair enzyme O6-methylguanine-DNA methyltransferase in formalin-fixed, paraffin-embedded astrocytomas. Lab Invest. 1998, 78: 643-644.PubMed
28.
go back to reference Pollack IF, Hamilton RL, Sobol RW, Burnham J, Yates AJ, Holmes EJ, Zhou T, Finlay JL: O6-methylguanine-DNA methyltransferase expression strongly correlates with outcome in childhood malignant gliomas: results from the CCG-945 Cohort. J Clin Oncol. 2006, 24: 3431-3437. 10.1200/JCO.2006.05.7265.PubMed Pollack IF, Hamilton RL, Sobol RW, Burnham J, Yates AJ, Holmes EJ, Zhou T, Finlay JL: O6-methylguanine-DNA methyltransferase expression strongly correlates with outcome in childhood malignant gliomas: results from the CCG-945 Cohort. J Clin Oncol. 2006, 24: 3431-3437. 10.1200/JCO.2006.05.7265.PubMed
29.
go back to reference Rodriguez FJ, Thibodeau SN, Jenkins RB, Schowalter KV, Caron BL, O'Neil BP, James CD, Passe S, Slezak J, Giannini C: MGMT Immunohistochemical expression and promoter methylation in human glioblastoma. Appl Immunohistochem Mol Morphol. 2008, 16: 59-65.PubMed Rodriguez FJ, Thibodeau SN, Jenkins RB, Schowalter KV, Caron BL, O'Neil BP, James CD, Passe S, Slezak J, Giannini C: MGMT Immunohistochemical expression and promoter methylation in human glioblastoma. Appl Immunohistochem Mol Morphol. 2008, 16: 59-65.PubMed
30.
go back to reference Yachi K, Watanabe T, Ohta T, Fukushima T, Yoshino A, Ogino A, Katayama Y, Nagase H: Relevance of MSP assay for the detection of MGMT promoter hypermethylation in glioblastomas. Int J Oncol. 2008, 33: 469-475.PubMed Yachi K, Watanabe T, Ohta T, Fukushima T, Yoshino A, Ogino A, Katayama Y, Nagase H: Relevance of MSP assay for the detection of MGMT promoter hypermethylation in glioblastomas. Int J Oncol. 2008, 33: 469-475.PubMed
31.
go back to reference Brell M, Tortosa A, Verger E, Gil JM, Viñolas N, Villà S, Acebes JJ, Caral Pons JJ, Pujol T, Ferrer I, Ribalta T, Graus F: Prognostic significance of O6 - Methilguanine DNA methyltransferase determined by promoter methylation and immunohistochemical expression in anaplastic gliomas. Clin Cancer Res. 2005, 11: 5167-5171. 10.1158/1078-0432.CCR-05-0230.PubMed Brell M, Tortosa A, Verger E, Gil JM, Viñolas N, Villà S, Acebes JJ, Caral Pons JJ, Pujol T, Ferrer I, Ribalta T, Graus F: Prognostic significance of O6 - Methilguanine DNA methyltransferase determined by promoter methylation and immunohistochemical expression in anaplastic gliomas. Clin Cancer Res. 2005, 11: 5167-5171. 10.1158/1078-0432.CCR-05-0230.PubMed
32.
go back to reference Ingold B, Schraml P, Heppner FL, Moch H: Homogeneous MGMT immunoreactivity correlates with an unmethylated MGMT promoter status in brain metastases of various solid tumors. PLoS ONE. 2009, 4: e4775-10.1371/journal.pone.0004775.PubMedPubMedCentral Ingold B, Schraml P, Heppner FL, Moch H: Homogeneous MGMT immunoreactivity correlates with an unmethylated MGMT promoter status in brain metastases of various solid tumors. PLoS ONE. 2009, 4: e4775-10.1371/journal.pone.0004775.PubMedPubMedCentral
33.
go back to reference Preusser M: MGMT analysis at DNA, RNA and protein levels in glioblastoma tissue. Histol Histopathol. 2009, 24: 511-518.PubMed Preusser M: MGMT analysis at DNA, RNA and protein levels in glioblastoma tissue. Histol Histopathol. 2009, 24: 511-518.PubMed
34.
go back to reference Leeflang MM, Deeks JJ, Gatsonis C, Bossuyt PM: Systematic reviews of diagnostic test accuracy. Ann Intern Med. 2008, 149: 889-897.PubMedPubMedCentral Leeflang MM, Deeks JJ, Gatsonis C, Bossuyt PM: Systematic reviews of diagnostic test accuracy. Ann Intern Med. 2008, 149: 889-897.PubMedPubMedCentral
35.
go back to reference Irwig L, Tosteson AN, Gatsonis C, Lau J, Colditz G, Chalmers TC, Mosteller F: Guidelines for meta-analyses evaluating diagnostic tests. Ann Intern Med. 1994, 120: 667-676.PubMed Irwig L, Tosteson AN, Gatsonis C, Lau J, Colditz G, Chalmers TC, Mosteller F: Guidelines for meta-analyses evaluating diagnostic tests. Ann Intern Med. 1994, 120: 667-676.PubMed
36.
go back to reference Deville WL, Buntinx F, Bouter LM, Montori VM, de Vet HC, van der Windt DA, bezemer PD: Conducting systematic reviews of diagnostic studies: didactic guidelines. BMC Med Res Methodol. 2002, 2: 9-10.1186/1471-2288-2-9.PubMedPubMedCentral Deville WL, Buntinx F, Bouter LM, Montori VM, de Vet HC, van der Windt DA, bezemer PD: Conducting systematic reviews of diagnostic studies: didactic guidelines. BMC Med Res Methodol. 2002, 2: 9-10.1186/1471-2288-2-9.PubMedPubMedCentral
37.
go back to reference Virgili G, Conti AA, Murro V, Gensini GF, Gusinu R: Systematic reviews of diagnostic test accuracy and the Cochrane collaboration. Intern Emerg Med. 2009, 4: 255-258. 10.1007/s11739-009-0243-6.PubMed Virgili G, Conti AA, Murro V, Gensini GF, Gusinu R: Systematic reviews of diagnostic test accuracy and the Cochrane collaboration. Intern Emerg Med. 2009, 4: 255-258. 10.1007/s11739-009-0243-6.PubMed
38.
go back to reference Whiting P, Rutjes AW, Reitsma JB, Bossuyt PM, Kleijnen J: The development of QUADAS: a tool for the quality assessment of studies of diagnostic accuracy included in systematic reviews. BMC Med Res Methodol. 2003, 3: 25-10.1186/1471-2288-3-25.PubMedPubMedCentral Whiting P, Rutjes AW, Reitsma JB, Bossuyt PM, Kleijnen J: The development of QUADAS: a tool for the quality assessment of studies of diagnostic accuracy included in systematic reviews. BMC Med Res Methodol. 2003, 3: 25-10.1186/1471-2288-3-25.PubMedPubMedCentral
39.
40.
go back to reference Bossuyt PM, Reitsma JB, Bruns DE, Gatsonis CA, Glasziou PP, Irwig LM, Lijmer JG, Moher D, Rennie D, de Vet HC: Towards complete and accurate reporting of studies of diagnostic accuracy: The STARD Initiative. Ann Intern Med. 2003, 138: 40-44.PubMed Bossuyt PM, Reitsma JB, Bruns DE, Gatsonis CA, Glasziou PP, Irwig LM, Lijmer JG, Moher D, Rennie D, de Vet HC: Towards complete and accurate reporting of studies of diagnostic accuracy: The STARD Initiative. Ann Intern Med. 2003, 138: 40-44.PubMed
41.
go back to reference Glas AS, Lijmer JG, Prins MH, Bonsel GJ, Bossuyt PM: The diagnostic odds ratio: a single indicator of test performance. J Clin Epidemiol. 2003, 56: 1129-1135. 10.1016/S0895-4356(03)00177-X.PubMed Glas AS, Lijmer JG, Prins MH, Bonsel GJ, Bossuyt PM: The diagnostic odds ratio: a single indicator of test performance. J Clin Epidemiol. 2003, 56: 1129-1135. 10.1016/S0895-4356(03)00177-X.PubMed
42.
go back to reference Higgins JP, Thompson SG, Deeks JJ, Altman DG: Measuring inconsistency in meta-analyses. BMJ. 2003, 327: 557-560. 10.1136/bmj.327.7414.557.PubMedPubMedCentral Higgins JP, Thompson SG, Deeks JJ, Altman DG: Measuring inconsistency in meta-analyses. BMJ. 2003, 327: 557-560. 10.1136/bmj.327.7414.557.PubMedPubMedCentral
43.
go back to reference Sterne JA, Egger M: Funnel plots for detecting bias in meta-analysis: guidelines on choice of axis. J Clin Epidemiol. 2001, 54: 1046-1055. 10.1016/S0895-4356(01)00377-8.PubMed Sterne JA, Egger M: Funnel plots for detecting bias in meta-analysis: guidelines on choice of axis. J Clin Epidemiol. 2001, 54: 1046-1055. 10.1016/S0895-4356(01)00377-8.PubMed
44.
go back to reference Egger M, Smith GD, Schneider M, Minder C: Bias in meta-analysis detected by a simple, graphical test. BMJ. 1997, 315: 629-634.PubMedPubMedCentral Egger M, Smith GD, Schneider M, Minder C: Bias in meta-analysis detected by a simple, graphical test. BMJ. 1997, 315: 629-634.PubMedPubMedCentral
45.
go back to reference Zamora J, Abraira V, Muriel A, Khan K, Coomarasamy A: Meta-DiSc: a software for meta-analysis of test accuracy data. BMC Med Res Methodol. 2006, 6: 31-10.1186/1471-2288-6-31.PubMedPubMedCentral Zamora J, Abraira V, Muriel A, Khan K, Coomarasamy A: Meta-DiSc: a software for meta-analysis of test accuracy data. BMC Med Res Methodol. 2006, 6: 31-10.1186/1471-2288-6-31.PubMedPubMedCentral
46.
go back to reference Karayan-Tapon L, Quillien V, Guilhot J, Wager M, Fromont G, Saikali S, Etcheverry A, Hamlat A, Loussouarn D, Campion L, Campone M, Vallette FM, Gratas-Rabbia C: Prognostic value of O(6)-methylguanine-DNA methyltransferase status in glioblastoma patients, assessed by five different methods. J Neurooncol. 2010, 97: 311-322. 10.1007/s11060-009-0031-1.PubMed Karayan-Tapon L, Quillien V, Guilhot J, Wager M, Fromont G, Saikali S, Etcheverry A, Hamlat A, Loussouarn D, Campion L, Campone M, Vallette FM, Gratas-Rabbia C: Prognostic value of O(6)-methylguanine-DNA methyltransferase status in glioblastoma patients, assessed by five different methods. J Neurooncol. 2010, 97: 311-322. 10.1007/s11060-009-0031-1.PubMed
47.
go back to reference Rood BR, Zhang H, Cogen PH: Intercellular heterogeneity of expression of the MGMT DNA repair gene in pediatric medulloblastoma. Neuro-Oncology. 2004, 6: 200-207. 10.1215/S1152851703000565.PubMedPubMedCentral Rood BR, Zhang H, Cogen PH: Intercellular heterogeneity of expression of the MGMT DNA repair gene in pediatric medulloblastoma. Neuro-Oncology. 2004, 6: 200-207. 10.1215/S1152851703000565.PubMedPubMedCentral
48.
go back to reference Zhang D, Bai Y, Wang Y, Luo J, Ge Q, Qiao Y, Jia C, Lu Z: Detailed methylation patterns and protein expression profiles of MGMT in colorectal carcinoma surgical margins. Clin Biochem. 2008, 41: 19-25. 10.1016/j.clinbiochem.2007.09.010.PubMed Zhang D, Bai Y, Wang Y, Luo J, Ge Q, Qiao Y, Jia C, Lu Z: Detailed methylation patterns and protein expression profiles of MGMT in colorectal carcinoma surgical margins. Clin Biochem. 2008, 41: 19-25. 10.1016/j.clinbiochem.2007.09.010.PubMed
49.
go back to reference Voelter V, Diserens AC, Moulin A, Nagel G, Yan P, Migliavacca E, Rimoldi D, Hamou MF, Kaina B, Leyvraz S, Hegi ME: Infrequent promoter methylation of the MGMT gene in liver metastases from uveal melanoma. Int J Cancer. 2008, 123: 1215-1218. 10.1002/ijc.23632.PubMed Voelter V, Diserens AC, Moulin A, Nagel G, Yan P, Migliavacca E, Rimoldi D, Hamou MF, Kaina B, Leyvraz S, Hegi ME: Infrequent promoter methylation of the MGMT gene in liver metastases from uveal melanoma. Int J Cancer. 2008, 123: 1215-1218. 10.1002/ijc.23632.PubMed
50.
go back to reference Martin P, Garcia-Cosio M, Santon A, Bellas C: Aberrant gene promoter methylation in plasma cell dyscrasias. Exp Mol Pathol. 2008, 84: 256-261. 10.1016/j.yexmp.2008.02.003.PubMed Martin P, Garcia-Cosio M, Santon A, Bellas C: Aberrant gene promoter methylation in plasma cell dyscrasias. Exp Mol Pathol. 2008, 84: 256-261. 10.1016/j.yexmp.2008.02.003.PubMed
51.
go back to reference Rietschel P, Wolchok JD, Krown S, Gerst S, Jungbluth AA, Busam K, Smith K, Orlow I, Panageas K, Chapman PB: Phase II study of extended-dose temozolomide in patients with melanoma. J Clin Oncol. 2008, 26: 2299-2304. 10.1200/JCO.2007.14.5292.PubMed Rietschel P, Wolchok JD, Krown S, Gerst S, Jungbluth AA, Busam K, Smith K, Orlow I, Panageas K, Chapman PB: Phase II study of extended-dose temozolomide in patients with melanoma. J Clin Oncol. 2008, 26: 2299-2304. 10.1200/JCO.2007.14.5292.PubMed
52.
go back to reference Lin Z, Gao M, Zhang X, Kim YS, Lee ES, Kim HK, Kim I: The hypermethylation and protein expression of p16 INK4A and DNA repair gene O6-methylguanine-DNA methyltransferase in various uterine cervical lesions. J Cancer Res Clin Oncol. 2005, 131: 364-370. 10.1007/s00432-004-0657-5.PubMed Lin Z, Gao M, Zhang X, Kim YS, Lee ES, Kim HK, Kim I: The hypermethylation and protein expression of p16 INK4A and DNA repair gene O6-methylguanine-DNA methyltransferase in various uterine cervical lesions. J Cancer Res Clin Oncol. 2005, 131: 364-370. 10.1007/s00432-004-0657-5.PubMed
53.
go back to reference Furonaka O, Takeshima Y, Awaya H, Kushitani K, Kohno N, Inai K: Aberrant methylation and loss of expression of O6-Methylguanine-DNA methyltransferase in pulmonary squamous cell carcinoma and adenocarcinoma. Pathol Int. 2005, 55: 303-309. 10.1111/j.1440-1827.2005.01830.x.PubMed Furonaka O, Takeshima Y, Awaya H, Kushitani K, Kohno N, Inai K: Aberrant methylation and loss of expression of O6-Methylguanine-DNA methyltransferase in pulmonary squamous cell carcinoma and adenocarcinoma. Pathol Int. 2005, 55: 303-309. 10.1111/j.1440-1827.2005.01830.x.PubMed
54.
go back to reference Brock MV, Gou M, Akiyama Y, Muller A, Wu TT, Montgomery E, Deasel M, Germonpré P, Rubinson L, Heitmiller RH, Yang SC, Forastiere AA, Baylin SB, Herman JG: Prognostic importance of promoter hypermethylation of multiple genes in esophageal adenocarcinoma. Clin Cancer Res. 2003, 9: 2912-2919.PubMed Brock MV, Gou M, Akiyama Y, Muller A, Wu TT, Montgomery E, Deasel M, Germonpré P, Rubinson L, Heitmiller RH, Yang SC, Forastiere AA, Baylin SB, Herman JG: Prognostic importance of promoter hypermethylation of multiple genes in esophageal adenocarcinoma. Clin Cancer Res. 2003, 9: 2912-2919.PubMed
55.
go back to reference Nagasaka T, Sharp GB, Notohara K, Kambara T, Sasamoto H, Isozaki H, MacPhee DG, Jass JR, Tanaka N, Matsubara N: Hypermethylation of O6-Methylguanine-DNA methyltransefarse promoter may predict nonrecurrence after chemotherapy in colorectal cancer cases. Clin Cancer Res. 2003, 9: 5306-5312.PubMed Nagasaka T, Sharp GB, Notohara K, Kambara T, Sasamoto H, Isozaki H, MacPhee DG, Jass JR, Tanaka N, Matsubara N: Hypermethylation of O6-Methylguanine-DNA methyltransefarse promoter may predict nonrecurrence after chemotherapy in colorectal cancer cases. Clin Cancer Res. 2003, 9: 5306-5312.PubMed
56.
go back to reference Zhang L, Lu W, Miao X, Xing D, Tan W, Lin D: Inactivation of DNA repair gene O6-Methylguanine-DNA methyltransferase by promoter hypermethylation and its relation to p53 mutations in esophageal squamous cell carcinoma. Carcinogenesis. 2003, 24: 1039-1044. 10.1093/carcin/bgg062.PubMed Zhang L, Lu W, Miao X, Xing D, Tan W, Lin D: Inactivation of DNA repair gene O6-Methylguanine-DNA methyltransferase by promoter hypermethylation and its relation to p53 mutations in esophageal squamous cell carcinoma. Carcinogenesis. 2003, 24: 1039-1044. 10.1093/carcin/bgg062.PubMed
57.
go back to reference Matsukura S, Soejima H, Nakagawachi T, Yakushiji H, Ogawa A, Fukuhara M, Miyazaki K, Nakabeppu Y, Sekiguchi M, Mukai T: CpG methylation of MGMT and hMLH1 promoter in hepatocellular carcinoma associated with hepatitis viral infection. Br J Cancer. 2003, 88: 521-529. 10.1038/sj.bjc.6600743.PubMedPubMedCentral Matsukura S, Soejima H, Nakagawachi T, Yakushiji H, Ogawa A, Fukuhara M, Miyazaki K, Nakabeppu Y, Sekiguchi M, Mukai T: CpG methylation of MGMT and hMLH1 promoter in hepatocellular carcinoma associated with hepatitis viral infection. Br J Cancer. 2003, 88: 521-529. 10.1038/sj.bjc.6600743.PubMedPubMedCentral
58.
go back to reference Mellai M, Caldera V, Annovazzi L, Chio A, Lanotte M, Cassoni P, Finocchiaro G, Schiffer D: MGMT promoter hypermethylation in a series of 104 glioblastomas. Cancer Genomics Proteomics. 2009, 6: 219-227.PubMed Mellai M, Caldera V, Annovazzi L, Chio A, Lanotte M, Cassoni P, Finocchiaro G, Schiffer D: MGMT promoter hypermethylation in a series of 104 glioblastomas. Cancer Genomics Proteomics. 2009, 6: 219-227.PubMed
59.
go back to reference Yang SH, Kim YH, Kim JW, Park CK, Park SH, Jung HW: Methylation status of the O6-Methylguanine-deoxyribonucleic acid methyltransferase gene promoter in World Health Organization grade III gliomas. J Korean Neurosurg Soc. 2009, 46: 385-388. 10.3340/jkns.2009.46.4.385.PubMedPubMedCentral Yang SH, Kim YH, Kim JW, Park CK, Park SH, Jung HW: Methylation status of the O6-Methylguanine-deoxyribonucleic acid methyltransferase gene promoter in World Health Organization grade III gliomas. J Korean Neurosurg Soc. 2009, 46: 385-388. 10.3340/jkns.2009.46.4.385.PubMedPubMedCentral
60.
go back to reference Herfarth KK, Brent TP, Danam RP, Remack JS, Kodner IJ, Wells SA, Goodfellow PJ: A specific CpG methylation pattern of the MGMT promoter region associated with reduced MGMT expression in primary colorectal cancers. Mol Carcinog. 1999, 24: 90-98. 10.1002/(SICI)1098-2744(199902)24:2<90::AID-MC3>3.0.CO;2-B.PubMed Herfarth KK, Brent TP, Danam RP, Remack JS, Kodner IJ, Wells SA, Goodfellow PJ: A specific CpG methylation pattern of the MGMT promoter region associated with reduced MGMT expression in primary colorectal cancers. Mol Carcinog. 1999, 24: 90-98. 10.1002/(SICI)1098-2744(199902)24:2<90::AID-MC3>3.0.CO;2-B.PubMed
61.
go back to reference Yin D, Xie D, Hofmann WK, Zhang W, Asotra K, Wong R, Black KL, Koeffler HP: DNA repair gene O6-methylguanine-DNA methyltransferase: promoter hypermethylation associated with decreased expression and G:C to A:T mutations of p53 in brain tumors. Mol Carcinog. 2003, 36: 23-31. 10.1002/mc.10094.PubMed Yin D, Xie D, Hofmann WK, Zhang W, Asotra K, Wong R, Black KL, Koeffler HP: DNA repair gene O6-methylguanine-DNA methyltransferase: promoter hypermethylation associated with decreased expression and G:C to A:T mutations of p53 in brain tumors. Mol Carcinog. 2003, 36: 23-31. 10.1002/mc.10094.PubMed
62.
go back to reference Lazcoz P, Munoz J, Nistal M, Pestana A, Encio IJ, Castresana JS: Loss of heterozygosity and microsatellite instability on chromosome arm 10q in neuroblastoma. Cancer Genet Cytogenet. 2007, 174: 1-8. 10.1016/j.cancergencyto.2006.08.014.PubMed Lazcoz P, Munoz J, Nistal M, Pestana A, Encio IJ, Castresana JS: Loss of heterozygosity and microsatellite instability on chromosome arm 10q in neuroblastoma. Cancer Genet Cytogenet. 2007, 174: 1-8. 10.1016/j.cancergencyto.2006.08.014.PubMed
63.
go back to reference Qi J, Zhu YQ, Huang MF, Yang D: Hypermethylation of CpG island in O6-methylguanine-DNA methyltransferase gene was associated with K-ras G to A mutation in colorectal tumor. World J Gastroenterol. 2005, 11: 2022-2025.PubMedPubMedCentral Qi J, Zhu YQ, Huang MF, Yang D: Hypermethylation of CpG island in O6-methylguanine-DNA methyltransferase gene was associated with K-ras G to A mutation in colorectal tumor. World J Gastroenterol. 2005, 11: 2022-2025.PubMedPubMedCentral
64.
go back to reference Rimel BJ, Huettner P, Powell MA, Mutch DG, Goodfellow PJ: Absence of MGMT promoter methylation in endometrial cancer. Gynecol Oncol. 2009, 112: 224-228. 10.1016/j.ygyno.2008.08.038.PubMed Rimel BJ, Huettner P, Powell MA, Mutch DG, Goodfellow PJ: Absence of MGMT promoter methylation in endometrial cancer. Gynecol Oncol. 2009, 112: 224-228. 10.1016/j.ygyno.2008.08.038.PubMed
65.
go back to reference McCormack AI, McDonald KL, Gill AJ, Clark SJ, Burt MG, Campbell KA, Braund WJ, Little NS, Cook RJ, Grossman AB, Robinson BG, Clifton-Bligh RJ: Low O(6)-methylguanine-DNA methyltransferase (MGMT) expression and response to temozolomide in aggressive pituitary tumours. Clin Endocrinol (Oxf). 2009, 71: 226-233. 10.1111/j.1365-2265.2008.03487.x. McCormack AI, McDonald KL, Gill AJ, Clark SJ, Burt MG, Campbell KA, Braund WJ, Little NS, Cook RJ, Grossman AB, Robinson BG, Clifton-Bligh RJ: Low O(6)-methylguanine-DNA methyltransferase (MGMT) expression and response to temozolomide in aggressive pituitary tumours. Clin Endocrinol (Oxf). 2009, 71: 226-233. 10.1111/j.1365-2265.2008.03487.x.
66.
go back to reference Nagasaka T, Goel A, Notohara K, Takahata T, Sasamoto H, Uchida T, Nishida N, Tanaka N, Boland CR, Matsubara N: Methylation pattern of the O6-methylguanine-DNA methyltransferase gene in colon during progressive colorectal tumorigenesis. Int J Cancer. 2008, 122: 2429-2436. 10.1002/ijc.23398.PubMedPubMedCentral Nagasaka T, Goel A, Notohara K, Takahata T, Sasamoto H, Uchida T, Nishida N, Tanaka N, Boland CR, Matsubara N: Methylation pattern of the O6-methylguanine-DNA methyltransferase gene in colon during progressive colorectal tumorigenesis. Int J Cancer. 2008, 122: 2429-2436. 10.1002/ijc.23398.PubMedPubMedCentral
67.
go back to reference Baumann S, Keller G, Puhringer F, Napieralski R, Feith M, Langer R, Hofler H, Stein HJ, Sarbia M: The prognostic impact of O6-Methylguanine-DNA Methyltransferase (MGMT) promotor hypermethylation in esophageal adenocarcinoma. Int J Cancer. 2006, 119: 264-268. 10.1002/ijc.21848.PubMed Baumann S, Keller G, Puhringer F, Napieralski R, Feith M, Langer R, Hofler H, Stein HJ, Sarbia M: The prognostic impact of O6-Methylguanine-DNA Methyltransferase (MGMT) promotor hypermethylation in esophageal adenocarcinoma. Int J Cancer. 2006, 119: 264-268. 10.1002/ijc.21848.PubMed
68.
go back to reference Maxwell JA, Johnson SP, Quinn A, McLendon RE, Ali-Osman F, Friedman AH, Herndon JE, Bierau K, Bigley J, Bigner DD, Friedman HS: Quantitative analysis of O6-alkylguanine-DNA alkyltransefarse in malignant glioma. Mol Cancer Ther. 2006, 5: 2531-2539. 10.1158/1535-7163.MCT-06-0106.PubMed Maxwell JA, Johnson SP, Quinn A, McLendon RE, Ali-Osman F, Friedman AH, Herndon JE, Bierau K, Bigley J, Bigner DD, Friedman HS: Quantitative analysis of O6-alkylguanine-DNA alkyltransefarse in malignant glioma. Mol Cancer Ther. 2006, 5: 2531-2539. 10.1158/1535-7163.MCT-06-0106.PubMed
69.
go back to reference Chu LC, Eberhart CG, Grossman SA, Herman JG: Epigenetic silencing of multiple genes in primary CNS lymphoma. Int J Cancer. 2006, 119: 2487-2491. 10.1002/ijc.22124.PubMed Chu LC, Eberhart CG, Grossman SA, Herman JG: Epigenetic silencing of multiple genes in primary CNS lymphoma. Int J Cancer. 2006, 119: 2487-2491. 10.1002/ijc.22124.PubMed
70.
go back to reference Uccella S, Cerutti R, Placidi C, Marchet S, Carnevali I, Bernasconi B, Proserpio I, Pinotti G, Tibiletti MG, Furlan D, Capella C: MGMT methylation in diffuse large B-cell lymphoma: validation of quantitative methylation-specific PCR and comparison with MGMT protein expression. J Clin Pathol. 2009, 62: 715-723. 10.1136/jcp.2009.064741.PubMed Uccella S, Cerutti R, Placidi C, Marchet S, Carnevali I, Bernasconi B, Proserpio I, Pinotti G, Tibiletti MG, Furlan D, Capella C: MGMT methylation in diffuse large B-cell lymphoma: validation of quantitative methylation-specific PCR and comparison with MGMT protein expression. J Clin Pathol. 2009, 62: 715-723. 10.1136/jcp.2009.064741.PubMed
71.
go back to reference Möllemann M, Wolter M, Felsberg J, Collins VP, Reifenberger G: Frequent promoter hypermethylation and low expression of the MGMT gene in oligodendroglial tumors. Int J Cancer. 2005, 113: 379-385.PubMed Möllemann M, Wolter M, Felsberg J, Collins VP, Reifenberger G: Frequent promoter hypermethylation and low expression of the MGMT gene in oligodendroglial tumors. Int J Cancer. 2005, 113: 379-385.PubMed
72.
go back to reference Munot K, Bell SM, Lane S, Horgan K, Hanby AM, Speirs V: Pattern of expression of genes linked to epigenetic silencing in human breast cancer. Hum Pathol. 2006, 37: 989-999. 10.1016/j.humpath.2006.04.013.PubMed Munot K, Bell SM, Lane S, Horgan K, Hanby AM, Speirs V: Pattern of expression of genes linked to epigenetic silencing in human breast cancer. Hum Pathol. 2006, 37: 989-999. 10.1016/j.humpath.2006.04.013.PubMed
73.
go back to reference Wolf P, Hu YC, Doffek K, Sidransky D, Ahrendt SA: O(6)- Methylguanine-DNA methyltransferase promoter hypermethylation shifts the p53 mutational spectrum in non-small cell lung cancer. Cancer Res. 2001, 61: 8113-8117.PubMed Wolf P, Hu YC, Doffek K, Sidransky D, Ahrendt SA: O(6)- Methylguanine-DNA methyltransferase promoter hypermethylation shifts the p53 mutational spectrum in non-small cell lung cancer. Cancer Res. 2001, 61: 8113-8117.PubMed
74.
go back to reference Lee GW, Kang JH, Kim IS, Kim HG, Ko GH, Lee JH, Kim DC, Song DH, Yang JW, Lee JS: Is inactivation of O(6)-methylguanine DNA methyltransferase still a favorable prognostic factor of patients with diffuse large B-cell lymphoma in the era of R-CHOP chemotherapy?. Leuk Lymphoma. 2009, 50: 1992-1998. 10.3109/10428190903312462.PubMed Lee GW, Kang JH, Kim IS, Kim HG, Ko GH, Lee JH, Kim DC, Song DH, Yang JW, Lee JS: Is inactivation of O(6)-methylguanine DNA methyltransferase still a favorable prognostic factor of patients with diffuse large B-cell lymphoma in the era of R-CHOP chemotherapy?. Leuk Lymphoma. 2009, 50: 1992-1998. 10.3109/10428190903312462.PubMed
75.
go back to reference Herath NI, Walsh MD, Kew M, Smith JL, Jass JR, Young J, Leggett BA, Macdonald GA: Silencing of O6-methylguanine DNA methyltransferase in the absence of promoter hypermethylation in hepatocellular carcinomas from Australia and South Africa. Oncol Rep. 2007, 17: 817-822.PubMed Herath NI, Walsh MD, Kew M, Smith JL, Jass JR, Young J, Leggett BA, Macdonald GA: Silencing of O6-methylguanine DNA methyltransferase in the absence of promoter hypermethylation in hepatocellular carcinomas from Australia and South Africa. Oncol Rep. 2007, 17: 817-822.PubMed
76.
go back to reference Lavon I, Zrihan D, Zelikovitch B, Fellig Y, Fuchs D, Soffer D, Siegal T: Longitudinal assessment of genetic and epigenetic markers in oligodendrogliomas. Clin Cancer Res. 2007, 13: 1429-1437. 10.1158/1078-0432.CCR-06-2050.PubMed Lavon I, Zrihan D, Zelikovitch B, Fellig Y, Fuchs D, Soffer D, Siegal T: Longitudinal assessment of genetic and epigenetic markers in oligodendrogliomas. Clin Cancer Res. 2007, 13: 1429-1437. 10.1158/1078-0432.CCR-06-2050.PubMed
77.
go back to reference Martin P, Santon A, Garcia-Cosio M, Bellas C: hMLH1 and MGMT inactivation as a mechanism of tumorigenesis in monoclonal gammopathies. Mod Pathol. 2006, 19: 914-921. 10.1038/modpathol.3800590.PubMed Martin P, Santon A, Garcia-Cosio M, Bellas C: hMLH1 and MGMT inactivation as a mechanism of tumorigenesis in monoclonal gammopathies. Mod Pathol. 2006, 19: 914-921. 10.1038/modpathol.3800590.PubMed
78.
go back to reference Ogawa T, Yoshida T, Tsuruta T, Saigenji K, Okayasu I: Genetic instability on chromosome 17 in the epithelium of non-polypoid colorectal carcinomas compared to polypoid lesions. Cancer Sci. 2006, 97: 1335-1342. 10.1111/j.1349-7006.2006.00334.x.PubMed Ogawa T, Yoshida T, Tsuruta T, Saigenji K, Okayasu I: Genetic instability on chromosome 17 in the epithelium of non-polypoid colorectal carcinomas compared to polypoid lesions. Cancer Sci. 2006, 97: 1335-1342. 10.1111/j.1349-7006.2006.00334.x.PubMed
79.
go back to reference Rossi D, Capello D, Gloghini A, Franceschetti S, Paulli M, Saglio G, Vitolo U, Pileri SA, Esteller M, Carbone A, Gaidano G: Aberrant promoter methylation of multiple genes throughout the clinico-pathologic spectrum of B-cell neoplasia. Haematologia. 2004, 89: 154-164. Rossi D, Capello D, Gloghini A, Franceschetti S, Paulli M, Saglio G, Vitolo U, Pileri SA, Esteller M, Carbone A, Gaidano G: Aberrant promoter methylation of multiple genes throughout the clinico-pathologic spectrum of B-cell neoplasia. Haematologia. 2004, 89: 154-164.
80.
go back to reference Kim SH, Bae SI, Lee HS, Kim WH: Alteration of O6-methylguanie-DNA methyltransferase in colorectal neoplasms in sporadic and familial adenomatous polyposi patients. Mol Carcinog. 2003, 37: 32-38. 10.1002/mc.10116.PubMed Kim SH, Bae SI, Lee HS, Kim WH: Alteration of O6-methylguanie-DNA methyltransferase in colorectal neoplasms in sporadic and familial adenomatous polyposi patients. Mol Carcinog. 2003, 37: 32-38. 10.1002/mc.10116.PubMed
81.
go back to reference Choy KW, Pang CP, To KF, Yu C, Ng JSK, Lam DSC: Impaired expression and promotor hypermethylation of O6-Methylguanine-DNA Methyltransferase in retinoblastoma tissues. Invest Ophthalmol Vis Sci (PA). 2002, 43: 1344-1349. Choy KW, Pang CP, To KF, Yu C, Ng JSK, Lam DSC: Impaired expression and promotor hypermethylation of O6-Methylguanine-DNA Methyltransferase in retinoblastoma tissues. Invest Ophthalmol Vis Sci (PA). 2002, 43: 1344-1349.
82.
go back to reference Whitehall VL, Walsh MD, Young J, Leggett BA, Jass JR: Methylation of O6-methylguanine DNA methyltransferase characterizes a subset of colorectal cancer with low-level DNA microsatellite instability. Cancer Res. 2001, 61: 827-830.PubMed Whitehall VL, Walsh MD, Young J, Leggett BA, Jass JR: Methylation of O6-methylguanine DNA methyltransferase characterizes a subset of colorectal cancer with low-level DNA microsatellite instability. Cancer Res. 2001, 61: 827-830.PubMed
83.
go back to reference Wu PF, Kuo KT, Kuo LT, Lin YT, Lee WC, Lu YS, Yang CH, Wu RM, Tu YK, Tasi JC, Tseng HM, Tseng SH, Cheng AL, Lin CH: O(6)- Methylguanine-DNA methyltransferase expression and prognostic value in brain metastases of lung cancers. Lung Cancer. 2010, 68: 484-490. 10.1016/j.lungcan.2009.08.010.PubMed Wu PF, Kuo KT, Kuo LT, Lin YT, Lee WC, Lu YS, Yang CH, Wu RM, Tu YK, Tasi JC, Tseng HM, Tseng SH, Cheng AL, Lin CH: O(6)- Methylguanine-DNA methyltransferase expression and prognostic value in brain metastases of lung cancers. Lung Cancer. 2010, 68: 484-490. 10.1016/j.lungcan.2009.08.010.PubMed
84.
go back to reference Metellus P, Coulibaly B, Nanni I, Fina F, Eudes N, Giorgi R, Barrie M, Chinot O, Fuentes S, Dufour H, Ouafik L, Figarella-Branger D: Prognostic impact of O6-methylguanine-DNA methyltransferase silencing in patients with recurrent glioblastoma multiforme who undergo surgery and carmustine wafer implantation: a prospective patient cohort. Cancer. 2009, 115: 4783-4794. 10.1002/cncr.24546.PubMed Metellus P, Coulibaly B, Nanni I, Fina F, Eudes N, Giorgi R, Barrie M, Chinot O, Fuentes S, Dufour H, Ouafik L, Figarella-Branger D: Prognostic impact of O6-methylguanine-DNA methyltransferase silencing in patients with recurrent glioblastoma multiforme who undergo surgery and carmustine wafer implantation: a prospective patient cohort. Cancer. 2009, 115: 4783-4794. 10.1002/cncr.24546.PubMed
85.
go back to reference Sonoda Y, Kumabe T, Watanabe M, Nakazato Y, Inoue T, Kanamori M, Tominaga T: Long-term survivors of glioblastoma: clinical features and molecular analysis. Acta Neurochir (Wien). 2009, 151: 1349-1358. 10.1007/s00701-009-0387-1. Sonoda Y, Kumabe T, Watanabe M, Nakazato Y, Inoue T, Kanamori M, Tominaga T: Long-term survivors of glioblastoma: clinical features and molecular analysis. Acta Neurochir (Wien). 2009, 151: 1349-1358. 10.1007/s00701-009-0387-1.
86.
go back to reference Mikeska T, Bock C, El-Maarri O, Hubner A, Ehrentraut D, Schramm J, Felsberg J, Kahl P, Buttner R, Pietsch T, Waha A: Optimization of quantitative MGMT promoter methylation analysis using pyrosequencing and combined bisulfite restriction analysis. J Mol Diagn. 2007, 9: 368-381. 10.2353/jmoldx.2007.060167.PubMedPubMedCentral Mikeska T, Bock C, El-Maarri O, Hubner A, Ehrentraut D, Schramm J, Felsberg J, Kahl P, Buttner R, Pietsch T, Waha A: Optimization of quantitative MGMT promoter methylation analysis using pyrosequencing and combined bisulfite restriction analysis. J Mol Diagn. 2007, 9: 368-381. 10.2353/jmoldx.2007.060167.PubMedPubMedCentral
87.
go back to reference Parkinson JF, Wheeler HR, Clarkson A, Mckenkie CA, Biggs MT, Little NS, Cook RC, Messina M, Robinson BG, McDonald KL: Variation of O6-Methylguanine-DNA Methyltransferase (MGMT) promoter methylation in serial samples of glioblastoma. J Neurooncol. 2008, 87: 71-78. 10.1007/s11060-007-9486-0.PubMed Parkinson JF, Wheeler HR, Clarkson A, Mckenkie CA, Biggs MT, Little NS, Cook RC, Messina M, Robinson BG, McDonald KL: Variation of O6-Methylguanine-DNA Methyltransferase (MGMT) promoter methylation in serial samples of glioblastoma. J Neurooncol. 2008, 87: 71-78. 10.1007/s11060-007-9486-0.PubMed
88.
go back to reference Nakasu S, Fukami T, Baba K, Matsuda M: Immunohistochemical study for O6-Methylguanine-DNA methyltransferase in the non-neoplastic and neoplastic components of gliomas. J Neurooncol. 2004, 70: 333-340. 10.1007/s11060-004-9170-6.PubMed Nakasu S, Fukami T, Baba K, Matsuda M: Immunohistochemical study for O6-Methylguanine-DNA methyltransferase in the non-neoplastic and neoplastic components of gliomas. J Neurooncol. 2004, 70: 333-340. 10.1007/s11060-004-9170-6.PubMed
89.
go back to reference Grasbon-Frodl EM, Kreth FW, Ruiter M, Schnell O, Bise K, Felsberg J, Reifenberg G, Tonn JC, Kretzschmar HA: Intratumoral homogeinity of MGMT promoter hypermetilation as demonstrated in serial stereotactic specimens for anaplastic astrocytomas and glioblastomas. Int J Cancer. 2007, 121: 2458-2464. 10.1002/ijc.23020.PubMed Grasbon-Frodl EM, Kreth FW, Ruiter M, Schnell O, Bise K, Felsberg J, Reifenberg G, Tonn JC, Kretzschmar HA: Intratumoral homogeinity of MGMT promoter hypermetilation as demonstrated in serial stereotactic specimens for anaplastic astrocytomas and glioblastomas. Int J Cancer. 2007, 121: 2458-2464. 10.1002/ijc.23020.PubMed
90.
go back to reference Everhard S, Tost J, El AH, Criniere E, Busato F, Marie Y, Gut IG, Sanson M, Mokhtari K, Laigle-Donadey F, Hoang-Xuan K, Delattre JY, Thillet J: Identification of regions correlating MGMT promoter methylation and gene expression in glioblastomas. Neuro Oncol. 2009, 11: 348-356. 10.1215/15228517-2009-001.PubMedPubMedCentral Everhard S, Tost J, El AH, Criniere E, Busato F, Marie Y, Gut IG, Sanson M, Mokhtari K, Laigle-Donadey F, Hoang-Xuan K, Delattre JY, Thillet J: Identification of regions correlating MGMT promoter methylation and gene expression in glioblastomas. Neuro Oncol. 2009, 11: 348-356. 10.1215/15228517-2009-001.PubMedPubMedCentral
91.
go back to reference Kohonen-Corish MR, Daniel JJ, Chan C, Lin BP, Kwun SY, Dent OF, Dhillon VS, Trent RJ, Chapuis PH, Bokey EL: Low microsatellite instability is associated with poor prognosis in stage C colon cancer. J Clin Oncol. 2005, 23: 2318-2324. 10.1200/JCO.2005.00.109.PubMed Kohonen-Corish MR, Daniel JJ, Chan C, Lin BP, Kwun SY, Dent OF, Dhillon VS, Trent RJ, Chapuis PH, Bokey EL: Low microsatellite instability is associated with poor prognosis in stage C colon cancer. J Clin Oncol. 2005, 23: 2318-2324. 10.1200/JCO.2005.00.109.PubMed
92.
go back to reference Stupp R: Methylguanine methyltransefrase testing in glioblastoma: when and how?. J Clin Oncol. 2007, 25: 1459-1460. 10.1200/JCO.2006.09.7139.PubMed Stupp R: Methylguanine methyltransefrase testing in glioblastoma: when and how?. J Clin Oncol. 2007, 25: 1459-1460. 10.1200/JCO.2006.09.7139.PubMed
93.
go back to reference Shen L, Kondo Y, Rosner GL, Xiao L, Supunpong Hernandez N, Vilaythong J, Houlihan PS, Krouse RS, Prasad AR, Einspahr JG, Buckmeier J, Alberts DS, Hamilton SR, Issa J-PJ: MGMT promoter methylation and field defect in sporadic colorectal cancer. J Natl Cancer Inst. 2005, 97: 1330-1338. 10.1093/jnci/dji275.PubMed Shen L, Kondo Y, Rosner GL, Xiao L, Supunpong Hernandez N, Vilaythong J, Houlihan PS, Krouse RS, Prasad AR, Einspahr JG, Buckmeier J, Alberts DS, Hamilton SR, Issa J-PJ: MGMT promoter methylation and field defect in sporadic colorectal cancer. J Natl Cancer Inst. 2005, 97: 1330-1338. 10.1093/jnci/dji275.PubMed
94.
go back to reference Candiloro IL, Dobrovic A: Detection of MGMT promoter methylation in normal individuals is strongly associated with the T allele of the rs16906252 MGMT promoter single nucleotide polymorphism. Cancer Prev Res (Phila). 2009, 2: 862-867. 10.1158/1940-6207.CAPR-09-0056. Candiloro IL, Dobrovic A: Detection of MGMT promoter methylation in normal individuals is strongly associated with the T allele of the rs16906252 MGMT promoter single nucleotide polymorphism. Cancer Prev Res (Phila). 2009, 2: 862-867. 10.1158/1940-6207.CAPR-09-0056.
95.
go back to reference Park TJ, Han SU, Cho YK, Paik WK, Kim YB, Lim IK: Methylation of O6-Methylguanine-DNA methyltransferase gene is associated significantly with K-ras mutation, lymph node invasion, tumor staging, and disease free survival in patients with gastric carcinoma. Cancer. 2001, 92: 2760-2768. 10.1002/1097-0142(20011201)92:11<2760::AID-CNCR10123>3.0.CO;2-8.PubMed Park TJ, Han SU, Cho YK, Paik WK, Kim YB, Lim IK: Methylation of O6-Methylguanine-DNA methyltransferase gene is associated significantly with K-ras mutation, lymph node invasion, tumor staging, and disease free survival in patients with gastric carcinoma. Cancer. 2001, 92: 2760-2768. 10.1002/1097-0142(20011201)92:11<2760::AID-CNCR10123>3.0.CO;2-8.PubMed
96.
go back to reference Smith-Sorensen B, Lind GE, Skotheim RI, Fossa SD, Fodstad O, Stenwig A-E, Jakobsen KS, Lothe RA: Frequent promoter hypermethylation of the O6-Methylguanine-DNA methyltransferase (MGMT) gene in testicular cancer. Oncogene. 2002, 21: 8878-8884. 10.1038/sj.onc.1205978.PubMed Smith-Sorensen B, Lind GE, Skotheim RI, Fossa SD, Fodstad O, Stenwig A-E, Jakobsen KS, Lothe RA: Frequent promoter hypermethylation of the O6-Methylguanine-DNA methyltransferase (MGMT) gene in testicular cancer. Oncogene. 2002, 21: 8878-8884. 10.1038/sj.onc.1205978.PubMed
97.
go back to reference Bhakat KK, Mitra S: CpG methylation-dependent repression of the human O6-Methylguanine-DNA methyltransferase gene linked to chromatin structure alteration. Carcinogenesis. 2003, 24: 1337-1345. 10.1093/carcin/bgg086.PubMed Bhakat KK, Mitra S: CpG methylation-dependent repression of the human O6-Methylguanine-DNA methyltransferase gene linked to chromatin structure alteration. Carcinogenesis. 2003, 24: 1337-1345. 10.1093/carcin/bgg086.PubMed
98.
go back to reference Esteller M, Corn PG, Baylin SB, Herman JG: A gene hypermethylation profile of human cancer. Cancer Res. 2001, 61: 3225-3229.PubMed Esteller M, Corn PG, Baylin SB, Herman JG: A gene hypermethylation profile of human cancer. Cancer Res. 2001, 61: 3225-3229.PubMed
99.
go back to reference Lorente A, Mueller W, Urdangarin E, Lazcoz P, Lass U, von Deimling A, Castresana JS: RASSF1A, BLU, NORE1A, PTEN and MGMT expression and promoter methylation in gliomas and glioma cell lines and evidence of deregulated expression of de novo DNMTs. Brain Pathol. 2009, 19: 279-292. 10.1111/j.1750-3639.2008.00185.x.PubMed Lorente A, Mueller W, Urdangarin E, Lazcoz P, Lass U, von Deimling A, Castresana JS: RASSF1A, BLU, NORE1A, PTEN and MGMT expression and promoter methylation in gliomas and glioma cell lines and evidence of deregulated expression of de novo DNMTs. Brain Pathol. 2009, 19: 279-292. 10.1111/j.1750-3639.2008.00185.x.PubMed
100.
go back to reference Baeza N, Weller M, Yonekawa Y, Kleihues P, Ohgaki H: PTEN methylation and expression in glioblastomas. Acta Neuropathol. 2003, 106: 479-485. 10.1007/s00401-003-0748-4.PubMed Baeza N, Weller M, Yonekawa Y, Kleihues P, Ohgaki H: PTEN methylation and expression in glioblastomas. Acta Neuropathol. 2003, 106: 479-485. 10.1007/s00401-003-0748-4.PubMed
101.
go back to reference Iafrate AJ, Louis DN: "MGMT for pt mgmt": is Methylguanine-DNA Methyltransferase testing ready for patient management?. J Mol Diagn. 2008, 10: 308-310. 10.2353/jmoldx.2008.080043.PubMedPubMedCentral Iafrate AJ, Louis DN: "MGMT for pt mgmt": is Methylguanine-DNA Methyltransferase testing ready for patient management?. J Mol Diagn. 2008, 10: 308-310. 10.2353/jmoldx.2008.080043.PubMedPubMedCentral
102.
go back to reference Fritz G, Tano K, Mitra S, Kaina B: Inducibility of the DNA repair gene encoding O6-methylguanine-DNA methyltransferase in mammalian cells by DNA-damaging treatments. Mol Cell Biol. 1991, 11: 4660-4668.PubMedPubMedCentral Fritz G, Tano K, Mitra S, Kaina B: Inducibility of the DNA repair gene encoding O6-methylguanine-DNA methyltransferase in mammalian cells by DNA-damaging treatments. Mol Cell Biol. 1991, 11: 4660-4668.PubMedPubMedCentral
103.
go back to reference Cahill DP, Levine KK, Betensky RA, Codd PJ, Romany CA, Reavie LB, Batchelor TT, Futreal PA, Stratton MR, Curry WT, Iafrate AJ, Louis DN: Loss of the mismatch repair protein MSH6 in human glioblastomas is associated with tumor progression during temozolomide treatment. Clin Cancer Res. 2007, 13: 2038-2045. 10.1158/1078-0432.CCR-06-2149.PubMedPubMedCentral Cahill DP, Levine KK, Betensky RA, Codd PJ, Romany CA, Reavie LB, Batchelor TT, Futreal PA, Stratton MR, Curry WT, Iafrate AJ, Louis DN: Loss of the mismatch repair protein MSH6 in human glioblastomas is associated with tumor progression during temozolomide treatment. Clin Cancer Res. 2007, 13: 2038-2045. 10.1158/1078-0432.CCR-06-2149.PubMedPubMedCentral
104.
go back to reference Christmann M, Nagel G, Horn S, Krahn U, Wiewrodt D, Sommer C, Kaina B: MGMT activity, promoter methylation and immunohistochemistry of pretreatment and recurrent malignant gliomas: a comparative study on astrocytoma and glioblastoma. Int J Cancer. 2010, 127: 2106-2118. 10.1002/ijc.25229.PubMed Christmann M, Nagel G, Horn S, Krahn U, Wiewrodt D, Sommer C, Kaina B: MGMT activity, promoter methylation and immunohistochemistry of pretreatment and recurrent malignant gliomas: a comparative study on astrocytoma and glioblastoma. Int J Cancer. 2010, 127: 2106-2118. 10.1002/ijc.25229.PubMed
105.
go back to reference Eoli M, Menghi F, Bruzzone MG, De ST, Valletta L, Pollo B, Bissola L, Silvani A, Bianchessi D, D'Incerti L, Filippini G, Broggi G, Boiardi A, Finocchiaro G: Methylation of O6-methylguanine DNA methyltransferase and loss of heterozygosity on 19q and/or 17p are overlapping features of secondary glioblastomas with prolonged survival. Clin Cancer Res. 2007, 13: 2606-2613. 10.1158/1078-0432.CCR-06-2184.PubMed Eoli M, Menghi F, Bruzzone MG, De ST, Valletta L, Pollo B, Bissola L, Silvani A, Bianchessi D, D'Incerti L, Filippini G, Broggi G, Boiardi A, Finocchiaro G: Methylation of O6-methylguanine DNA methyltransferase and loss of heterozygosity on 19q and/or 17p are overlapping features of secondary glioblastomas with prolonged survival. Clin Cancer Res. 2007, 13: 2606-2613. 10.1158/1078-0432.CCR-06-2184.PubMed
106.
go back to reference Jung TY, Jung S, Moon KS, Kim IY, Kang SS, Kim YH, Park CS, Lee KH: Changes of the O6-methylguanine-DNA methyltransferase promoter methylation and MGMT protein expression after adjuvant treatment in glioblastoma. Oncol Rep. 2010, 23: 1269-1276. 10.3892/or_00000760.PubMed Jung TY, Jung S, Moon KS, Kim IY, Kang SS, Kim YH, Park CS, Lee KH: Changes of the O6-methylguanine-DNA methyltransferase promoter methylation and MGMT protein expression after adjuvant treatment in glioblastoma. Oncol Rep. 2010, 23: 1269-1276. 10.3892/or_00000760.PubMed
107.
go back to reference Nagane M, Kobayashi K, Ohnishi A, Shimizu S, Shiokawa Y: Prognostic significance of O6-methylguanine-DNA methyltransferase protein expression in patients with recurrent glioblastoma treated with temozolomide. Jpn J Clin Oncol. 2007, 37: 897-906. 10.1093/jjco/hym132.PubMed Nagane M, Kobayashi K, Ohnishi A, Shimizu S, Shiokawa Y: Prognostic significance of O6-methylguanine-DNA methyltransferase protein expression in patients with recurrent glioblastoma treated with temozolomide. Jpn J Clin Oncol. 2007, 37: 897-906. 10.1093/jjco/hym132.PubMed
108.
go back to reference Wiewrodt D, Nagel G, Dreimuller N, Hundsberger T, Perneczky A, Kaina B: MGMT in primary and recurrent human glioblastomas after radiation and chemotherapy and comparison with p53 status and clinical outcome. Int J Cancer. 2008, 122: 1391-1399. 10.1002/ijc.23219.PubMed Wiewrodt D, Nagel G, Dreimuller N, Hundsberger T, Perneczky A, Kaina B: MGMT in primary and recurrent human glioblastomas after radiation and chemotherapy and comparison with p53 status and clinical outcome. Int J Cancer. 2008, 122: 1391-1399. 10.1002/ijc.23219.PubMed
109.
go back to reference Brandes AA, Franceschi E, Tosoni A, Bartolini S, Bacci A, Agati R, Ghimenton C, Turazzi S, Talacchi A, Skrap M, Marucci G, Volpin L, Morandi L, Pizzolitto S, Gardiman M, Andreoli A, Calbucci F, Ermani M: O(6)-methylguanine DNA-methyltransferase methylation status can change between first surgery for newly diagnosed glioblastoma and second surgery for recurrence: clinical implications. Neuro Oncol. 2010, 12: 283-288.PubMedPubMedCentral Brandes AA, Franceschi E, Tosoni A, Bartolini S, Bacci A, Agati R, Ghimenton C, Turazzi S, Talacchi A, Skrap M, Marucci G, Volpin L, Morandi L, Pizzolitto S, Gardiman M, Andreoli A, Calbucci F, Ermani M: O(6)-methylguanine DNA-methyltransferase methylation status can change between first surgery for newly diagnosed glioblastoma and second surgery for recurrence: clinical implications. Neuro Oncol. 2010, 12: 283-288.PubMedPubMedCentral
110.
go back to reference Parkinson JF, Wheeler HT, McDonald KL: Contribution of DNA repair mechanisms to determining chemotherapy response in high-grade glioma. J Clin Neurosci. 2008, 15: 1-8. 10.1016/j.jocn.2007.06.005.PubMed Parkinson JF, Wheeler HT, McDonald KL: Contribution of DNA repair mechanisms to determining chemotherapy response in high-grade glioma. J Clin Neurosci. 2008, 15: 1-8. 10.1016/j.jocn.2007.06.005.PubMed
111.
go back to reference Candiloro IL, Mikeska T, Hokland P, Dobrovic A: Rapid analysis of heterogeneously methylated DNA using digital methylation-sensitive high resolution melting: application to the CDKN2B (p15) gene. Epigenetics Chromatin. 2008, 1: 7-10.1186/1756-8935-1-7.PubMedPubMedCentral Candiloro IL, Mikeska T, Hokland P, Dobrovic A: Rapid analysis of heterogeneously methylated DNA using digital methylation-sensitive high resolution melting: application to the CDKN2B (p15) gene. Epigenetics Chromatin. 2008, 1: 7-10.1186/1756-8935-1-7.PubMedPubMedCentral
112.
go back to reference Weller M, Stupp R, Reifenberger G, Brandes AA, van den Bent MJ, Wick W, Hegi ME: MGMT promoter methylation in malignant gliomas: ready for personalized medicine?. Nat Rev Neurol. 2010, 6: 39-51. 10.1038/nrneurol.2009.197.PubMed Weller M, Stupp R, Reifenberger G, Brandes AA, van den Bent MJ, Wick W, Hegi ME: MGMT promoter methylation in malignant gliomas: ready for personalized medicine?. Nat Rev Neurol. 2010, 6: 39-51. 10.1038/nrneurol.2009.197.PubMed
113.
go back to reference Anda T, Shabani HK, Tsunoda K, Tokunaga Y, Kaminogo M, Shitaba S, Hayashi T, Iseki M: Relationsip between expression of O6-methylguanine-DNA methyltransferase, glutathione-S-transferase π in glioblastoma and the survival of the patients treated with nimustine hydrochloride: An immunohistochemical analysis. Neurol Res. 2003, 25: 241-248. 10.1179/016164103101201445.PubMed Anda T, Shabani HK, Tsunoda K, Tokunaga Y, Kaminogo M, Shitaba S, Hayashi T, Iseki M: Relationsip between expression of O6-methylguanine-DNA methyltransferase, glutathione-S-transferase π in glioblastoma and the survival of the patients treated with nimustine hydrochloride: An immunohistochemical analysis. Neurol Res. 2003, 25: 241-248. 10.1179/016164103101201445.PubMed
114.
go back to reference Nakasu S, Fukami T, Jito J, Matsuda M: Prognostic significance of loss of O6-methylguanine-DNA methyltransferase expression in supratentorial diffuse low-grade astrocytoma. Surg Neurol. 2007, 68: 603-608. 10.1016/j.surneu.2006.12.053.PubMed Nakasu S, Fukami T, Jito J, Matsuda M: Prognostic significance of loss of O6-methylguanine-DNA methyltransferase expression in supratentorial diffuse low-grade astrocytoma. Surg Neurol. 2007, 68: 603-608. 10.1016/j.surneu.2006.12.053.PubMed
115.
go back to reference Nakagawa T, Ido K, Sakuma T, Takeuchi H, Sato K, Kubota T: Prognostic significance of the immunohistochemical expression of O6-methylguanine-DNA methyltransferase, P-glycoprotein, and multidrug resistance protein-1 in glioblastomas. Neuropathology. 2009, 29: 388-10.1111/j.1440-1789.2008.00983.x. Nakagawa T, Ido K, Sakuma T, Takeuchi H, Sato K, Kubota T: Prognostic significance of the immunohistochemical expression of O6-methylguanine-DNA methyltransferase, P-glycoprotein, and multidrug resistance protein-1 in glioblastomas. Neuropathology. 2009, 29: 388-10.1111/j.1440-1789.2008.00983.x.
116.
go back to reference Cao VT, Jung TY, Jung S, Jin SG, Moon KS, Kim IY, Kang SS, Park CS, Lee KH, Chae HJ: The correlation and prognostic significance of MGMT promoter methylation and MGMT protein in glioblastomas. Neurosurgery. 2009, 65: 866-875. 10.1227/01.NEU.0000357325.90347.A1.PubMed Cao VT, Jung TY, Jung S, Jin SG, Moon KS, Kim IY, Kang SS, Park CS, Lee KH, Chae HJ: The correlation and prognostic significance of MGMT promoter methylation and MGMT protein in glioblastomas. Neurosurgery. 2009, 65: 866-875. 10.1227/01.NEU.0000357325.90347.A1.PubMed
117.
go back to reference Sonoda Y, Yokosawa M, Saito R, Kanamori M, Yamashita Y, Kumabe T, Watanabe M, Tominaga T: O(6)-Methylguanine DNA methyltransferase determined by promoter hypermethylation and immunohistochemical expression is correlated with progression-free survival in patients with glioblastoma. Int J Clin Oncol. 2010, 15: 352-358. 10.1007/s10147-010-0065-6.PubMed Sonoda Y, Yokosawa M, Saito R, Kanamori M, Yamashita Y, Kumabe T, Watanabe M, Tominaga T: O(6)-Methylguanine DNA methyltransferase determined by promoter hypermethylation and immunohistochemical expression is correlated with progression-free survival in patients with glioblastoma. Int J Clin Oncol. 2010, 15: 352-358. 10.1007/s10147-010-0065-6.PubMed
118.
go back to reference Kuo LT, Kuo KT, Lee MJ, Wei CC, Scaravilli F, Tsai JC, Tseng HM, Kuo MF, Tu YK: Correlation among pathology, genetic and epigenetic profiles, and clinical outcome in oligodendroglial tumors. Int J Cancer. 2009, 124: 2872-2879. 10.1002/ijc.24303.PubMed Kuo LT, Kuo KT, Lee MJ, Wei CC, Scaravilli F, Tsai JC, Tseng HM, Kuo MF, Tu YK: Correlation among pathology, genetic and epigenetic profiles, and clinical outcome in oligodendroglial tumors. Int J Cancer. 2009, 124: 2872-2879. 10.1002/ijc.24303.PubMed
119.
go back to reference Felsberg J, Rapp M, Loeser S, Fimmers R, Stummer W, Goeppert M, Steiger HJ, Friedensdorf B, Reifenberger G, Sabel MC: Prognostic significance of molecular markers and extent of resection in primary glioblastoma patients. Clin Cancer Res. 2009, 15: 6683-6693. 10.1158/1078-0432.CCR-08-2801.PubMed Felsberg J, Rapp M, Loeser S, Fimmers R, Stummer W, Goeppert M, Steiger HJ, Friedensdorf B, Reifenberger G, Sabel MC: Prognostic significance of molecular markers and extent of resection in primary glioblastoma patients. Clin Cancer Res. 2009, 15: 6683-6693. 10.1158/1078-0432.CCR-08-2801.PubMed
120.
go back to reference Gerson SL: MGMT: its role in cancer aetiology and cancer therapeutics. Nat Rev Cancer. 2004, 4: 296-307. 10.1038/nrc1319.PubMed Gerson SL: MGMT: its role in cancer aetiology and cancer therapeutics. Nat Rev Cancer. 2004, 4: 296-307. 10.1038/nrc1319.PubMed
121.
go back to reference Esteller M, Herman JG: Generating mutations but providing chemosensitivity: the role of O6-Methylguanine DNA methyltransferase in human cancer. Oncogene. 2004, 23: 1-8. 10.1038/sj.onc.1207316.PubMed Esteller M, Herman JG: Generating mutations but providing chemosensitivity: the role of O6-Methylguanine DNA methyltransferase in human cancer. Oncogene. 2004, 23: 1-8. 10.1038/sj.onc.1207316.PubMed
122.
go back to reference Herman JG, Baylin SB: Gene silencing in cancer is association with promoter hypermethylation. N Engl J Med. 2003, 349: 2042-2054. 10.1056/NEJMra023075.PubMed Herman JG, Baylin SB: Gene silencing in cancer is association with promoter hypermethylation. N Engl J Med. 2003, 349: 2042-2054. 10.1056/NEJMra023075.PubMed
123.
go back to reference Deeks JJ: Systematic reviews in health care: Systematic reviews of evaluations of diagnostic and screening tests. BMJ. 2001, 323: 157-162. 10.1136/bmj.323.7305.157.PubMedPubMedCentral Deeks JJ: Systematic reviews in health care: Systematic reviews of evaluations of diagnostic and screening tests. BMJ. 2001, 323: 157-162. 10.1136/bmj.323.7305.157.PubMedPubMedCentral
124.
go back to reference Leeflang MM, Debets-Ossenkopp YJ, Visser CE, Scholten RJ, Hooft L, Bijlmer HA, Reitsma JB, Bossuyt PM, Vandenbroucke-Grauls CM: Galactomannan detection for invasive aspergillosis in immunocompromised patients. Cochrane Database Syst Rev. 2008, CD007394- Leeflang MM, Debets-Ossenkopp YJ, Visser CE, Scholten RJ, Hooft L, Bijlmer HA, Reitsma JB, Bossuyt PM, Vandenbroucke-Grauls CM: Galactomannan detection for invasive aspergillosis in immunocompromised patients. Cochrane Database Syst Rev. 2008, CD007394-
125.
go back to reference Sasai K, Nodagashira M, Aoyanagi E, Wang L, Katoh M, Murata J, Ozaki Y, Ito T, Fujimoto S, Kaneko S, Nagashima K, Tanaka S: Careful exclusion of non-neoplastic brain components is required for an appropiate evaluation of O6-methylguanine-DAN methyltransferase status in glioma. Am J Surg Pathol. 2008, 32: 1220-1227. 10.1097/PAS.0b013e318164c3f0.PubMed Sasai K, Nodagashira M, Aoyanagi E, Wang L, Katoh M, Murata J, Ozaki Y, Ito T, Fujimoto S, Kaneko S, Nagashima K, Tanaka S: Careful exclusion of non-neoplastic brain components is required for an appropiate evaluation of O6-methylguanine-DAN methyltransferase status in glioma. Am J Surg Pathol. 2008, 32: 1220-1227. 10.1097/PAS.0b013e318164c3f0.PubMed
126.
go back to reference Buccoliero AM, Castiglione F, Rossi Deglínnocenti D, Paglierani M, Maio V, Gheri CF, Garbini F, Moncini D, Taddei A, Sardi I, Sanzo M, Giordano F, Mussa F, Genitori L, Taddei GL: O6-Methylguanine-DNA-Methylytansefrase in recurring anaplastic ependymomas: PCR and immunohistochemistry. J Chemother. 2008, 20: 263-268.PubMed Buccoliero AM, Castiglione F, Rossi Deglínnocenti D, Paglierani M, Maio V, Gheri CF, Garbini F, Moncini D, Taddei A, Sardi I, Sanzo M, Giordano F, Mussa F, Genitori L, Taddei GL: O6-Methylguanine-DNA-Methylytansefrase in recurring anaplastic ependymomas: PCR and immunohistochemistry. J Chemother. 2008, 20: 263-268.PubMed
127.
go back to reference Cankovic M, Mikkelsen T, Rosenblum ML, Zarbo RJ: A simplified laboratory validated assay for MGMT promoter hypermethylation analysis of glioma specimens from formalin-fixed paraffin-embedded tissue. Lab Invest. 2007, 87: 392-397.PubMed Cankovic M, Mikkelsen T, Rosenblum ML, Zarbo RJ: A simplified laboratory validated assay for MGMT promoter hypermethylation analysis of glioma specimens from formalin-fixed paraffin-embedded tissue. Lab Invest. 2007, 87: 392-397.PubMed
128.
go back to reference Kim JI, Suh JT, Choi KU, Kang HJ, Shin DH, Lee IS, Moon TY, Kim WT: Inactivation of O(6)-methylguanine-DNA methyltransferase in soft tissue sarcomas: association with K-ras mutations. Hum Pathol. 2009, 40: 934-941. 10.1016/j.humpath.2009.01.005.PubMed Kim JI, Suh JT, Choi KU, Kang HJ, Shin DH, Lee IS, Moon TY, Kim WT: Inactivation of O(6)-methylguanine-DNA methyltransferase in soft tissue sarcomas: association with K-ras mutations. Hum Pathol. 2009, 40: 934-941. 10.1016/j.humpath.2009.01.005.PubMed
129.
go back to reference Zou XP, Zhang B, Zhang XQ, Chen M, Cao J, Liu WJ: Promoter hypermethylation of multiple genes in early gastric adenocarcinoma and precancerous lesions. Hum Pathol. 2009, 40: 1534-1542. 10.1016/j.humpath.2009.01.029.PubMed Zou XP, Zhang B, Zhang XQ, Chen M, Cao J, Liu WJ: Promoter hypermethylation of multiple genes in early gastric adenocarcinoma and precancerous lesions. Hum Pathol. 2009, 40: 1534-1542. 10.1016/j.humpath.2009.01.029.PubMed
130.
go back to reference Kuester D, El-Rifai W, Peng D, Ruemmele P, Kroeckel I, Peters B, Moskaluk CA, Stolte M, Monkemuller K, Meyer F, Schulz HU, Hartmann A, Roessner A, Schneider-Stock R: Silencing of MGMT expression by promoter hypermethylation in the metaplasia-dysplasia-carcinoma sequence of Barrett's esophagus. Cancer Lett. 2009, 275: 117-126. 10.1016/j.canlet.2008.10.009.PubMed Kuester D, El-Rifai W, Peng D, Ruemmele P, Kroeckel I, Peters B, Moskaluk CA, Stolte M, Monkemuller K, Meyer F, Schulz HU, Hartmann A, Roessner A, Schneider-Stock R: Silencing of MGMT expression by promoter hypermethylation in the metaplasia-dysplasia-carcinoma sequence of Barrett's esophagus. Cancer Lett. 2009, 275: 117-126. 10.1016/j.canlet.2008.10.009.PubMed
131.
go back to reference Mikami T, Yoshida T, Numata Y, Shiraishi H, Araki K, Guiot MC, Jass JR, Okayasu I: Low frequency of promoter methylation of O6-methylguanine DNA methyltransferase and hMLH1 in ulcerative colitis-associated tumors: comparison with sporadic colonic tumors. Am J Clin Pathol. 2007, 127: 366-373. 10.1309/RFETXN6387KLQ1LD.PubMed Mikami T, Yoshida T, Numata Y, Shiraishi H, Araki K, Guiot MC, Jass JR, Okayasu I: Low frequency of promoter methylation of O6-methylguanine DNA methyltransferase and hMLH1 in ulcerative colitis-associated tumors: comparison with sporadic colonic tumors. Am J Clin Pathol. 2007, 127: 366-373. 10.1309/RFETXN6387KLQ1LD.PubMed
132.
go back to reference Kawaguchi K, Oda Y, Saito T, Yamamoto H, Takahira T, Kobayashi C, Tamiya S, Tateishi N, Iwamoto Y, Tsuneyoshi M: DNA hypermethylation status of multiple genes in soft tissue sarcomas. Mod Pathol. 2006, 19: 106-114. 10.1038/modpathol.3800502.PubMed Kawaguchi K, Oda Y, Saito T, Yamamoto H, Takahira T, Kobayashi C, Tamiya S, Tateishi N, Iwamoto Y, Tsuneyoshi M: DNA hypermethylation status of multiple genes in soft tissue sarcomas. Mod Pathol. 2006, 19: 106-114. 10.1038/modpathol.3800502.PubMed
133.
go back to reference Fox EJ, Leahy DT, Geraghty R, Mulcahy HE, Fennelly D, Hyland JM, O'Donoghue DP, Sheahan K: Mutually exclusive promoter hypermethylation patterns of hMLH1 and O6-methylguanine DNA methyltransferase in colorectal cancer. J Mol Diagn. 2006, 8: 68-75. 10.2353/jmoldx.2006.050084.PubMedPubMedCentral Fox EJ, Leahy DT, Geraghty R, Mulcahy HE, Fennelly D, Hyland JM, O'Donoghue DP, Sheahan K: Mutually exclusive promoter hypermethylation patterns of hMLH1 and O6-methylguanine DNA methyltransferase in colorectal cancer. J Mol Diagn. 2006, 8: 68-75. 10.2353/jmoldx.2006.050084.PubMedPubMedCentral
134.
go back to reference Shen L, Kondo Y, Rosner GL, Xiao L, Supunpong Hernandez N, Vilaythong J, Houlihan PS, Krouse RS, Prasad AR, Einspahr JG, Buckmeier J, Alberts DS, Hamilton SR, Issa J-PJ: MGMT promoter methylation and field defect in sporadic colorectal cancer. J Natl Cancer Inst. 2005, 97: 1330-1338. 10.1093/jnci/dji275.PubMed Shen L, Kondo Y, Rosner GL, Xiao L, Supunpong Hernandez N, Vilaythong J, Houlihan PS, Krouse RS, Prasad AR, Einspahr JG, Buckmeier J, Alberts DS, Hamilton SR, Issa J-PJ: MGMT promoter methylation and field defect in sporadic colorectal cancer. J Natl Cancer Inst. 2005, 97: 1330-1338. 10.1093/jnci/dji275.PubMed
135.
go back to reference Koga Y, Kitajima Y, Miyoshi A, Sato K, Kitahara K, Soejima H, Miyazaki L: Tumor progression through epigenetic gene silencing of O(6)-methylguanine-DNA methyltransferase in human biliary tract cancers. Ann Surg Oncol. 2005, 12: 354-363. 10.1245/ASO.2005.07.020.PubMed Koga Y, Kitajima Y, Miyoshi A, Sato K, Kitahara K, Soejima H, Miyazaki L: Tumor progression through epigenetic gene silencing of O(6)-methylguanine-DNA methyltransferase in human biliary tract cancers. Ann Surg Oncol. 2005, 12: 354-363. 10.1245/ASO.2005.07.020.PubMed
136.
go back to reference Kang GH, Lee S, Lee HJ, Hwang KS: Aberrant CpG island hypermethylation of multiple genes in prostate cancer and prostatic intraepithelial neoplasia. J Pathol. 2004, 202: 233-240. 10.1002/path.1503.PubMed Kang GH, Lee S, Lee HJ, Hwang KS: Aberrant CpG island hypermethylation of multiple genes in prostate cancer and prostatic intraepithelial neoplasia. J Pathol. 2004, 202: 233-240. 10.1002/path.1503.PubMed
137.
go back to reference Zhang YJ, Chen Y, Ahsan H, Lunn RM, Lee PH, Chen CJ, Santella RM: Inactivation of the DNA repair gene O6-methylguanine-DNA methyltransferase by promoter hypermethylation and its relationship to aflatoxin B1-DNA adducts and p53 mutation in hepatocellular carcinoma. Int J Cancer. 2003, 103: 440-444. 10.1002/ijc.10852.PubMed Zhang YJ, Chen Y, Ahsan H, Lunn RM, Lee PH, Chen CJ, Santella RM: Inactivation of the DNA repair gene O6-methylguanine-DNA methyltransferase by promoter hypermethylation and its relationship to aflatoxin B1-DNA adducts and p53 mutation in hepatocellular carcinoma. Int J Cancer. 2003, 103: 440-444. 10.1002/ijc.10852.PubMed
138.
go back to reference Esteller M, Gaidano G, Goodman SN, Zagonel V, Capello D, Botto B, Rossi D, Gloghini A, Vitolo U, Carbone A, Baylin SB, Herman JG: Hypermethylation of the DNA repair gene O(6)-methylguanine DNA methyltransferase and survival of patients with diffuse large B-cell lymphoma. J Natl Cancer Inst. 2002, 94: 26-32.PubMed Esteller M, Gaidano G, Goodman SN, Zagonel V, Capello D, Botto B, Rossi D, Gloghini A, Vitolo U, Carbone A, Baylin SB, Herman JG: Hypermethylation of the DNA repair gene O(6)-methylguanine DNA methyltransferase and survival of patients with diffuse large B-cell lymphoma. J Natl Cancer Inst. 2002, 94: 26-32.PubMed
139.
go back to reference Hayashi H, Yazawa T, Okudela K, Nagai J, Ito T, Kanisawa M, Kitamura H: Inactivation of O6-Methylguanine-DNA Methyltransferase in human lung adenocarcinoma relates to high-grade histology and worse prognosis among smokers. Jpn J Cancer Res. 2002, 93: 184-189.PubMed Hayashi H, Yazawa T, Okudela K, Nagai J, Ito T, Kanisawa M, Kitamura H: Inactivation of O6-Methylguanine-DNA Methyltransferase in human lung adenocarcinoma relates to high-grade histology and worse prognosis among smokers. Jpn J Cancer Res. 2002, 93: 184-189.PubMed
Metadata
Title
O6-Methylguanine-DNA methyltransferase protein expression by immunohistochemistry in brain and non-brain systemic tumours: systematic review and meta-analysis of correlation with methylation-specific polymerase chain reaction
Authors
Marta Brell
Javier Ibáñez
Avelina Tortosa
Publication date
01-12-2011
Publisher
BioMed Central
Published in
BMC Cancer / Issue 1/2011
Electronic ISSN: 1471-2407
DOI
https://doi.org/10.1186/1471-2407-11-35

Other articles of this Issue 1/2011

BMC Cancer 1/2011 Go to the issue
Webinar | 19-02-2024 | 17:30 (CET)

Keynote webinar | Spotlight on antibody–drug conjugates in cancer

Antibody–drug conjugates (ADCs) are novel agents that have shown promise across multiple tumor types. Explore the current landscape of ADCs in breast and lung cancer with our experts, and gain insights into the mechanism of action, key clinical trials data, existing challenges, and future directions.

Dr. Véronique Diéras
Prof. Fabrice Barlesi
Developed by: Springer Medicine