Skip to main content
Key Specialties
Cardiology Diabetology Endocrinology Gastroenterology Geriatrics and Gerontology Gynecology and Obstetrics Hematology Infectious Disease Internal Medicine Nephrology Neurology Oncology Pediatrics Respiratory Medicine Rheumatology Surgery
Congress Coverage
2024 ACC Congress 2023 ESMO Congress 2023 EASD Congress 2023 ERS Congress 2023 ESC Congress 2023 EHA Congress 2023 ASCO Annual Meeting
Clinical Collections
Advances in Alzheimer’s

At a glance: The ONWARDS insulin icodec trials

A round-up of the ONWARDS phase 3 clinical trials evaluating the novel weekly insulin icodec in people with diabetes.
ADVANCED SEARCH
Log in
Top
Radiation Oncology
Published in: Radiation Oncology 1/2015

Open Access 01-12-2015 | Research

The SMAC mimetic BV6 sensitizes colorectal cancer cells to ionizing radiation by interfering with DNA repair processes and enhancing apoptosis

Authors: Stephanie Hehlgans, Julius Oppermann, Sebastian Reichert, Simone Fulda, Claus Rödel, Franz Rödel

Published in: Radiation Oncology | Issue 1/2015

Login to get access

Abstract

Background

In the present study, we aimed to investigate the effect of counteracting inhibitor of apoptosis (IAP) proteins using the small molecule Second Mitochondria-derived Activator of Caspase (SMAC) mimetic BV6 in combination with ionizing radiation on apoptosis, cell cycle regulation, DNA double-strand break (DSB) repair, three-dimensional (3D) clonogenic survival and expression of IAPs in colorectal carcinoma cells.

Material and methods

Colorectal cancer cell lines (HCT-15, HT-29, SW480) were subjected to BV6 treatment (0–4 μM) with or without irradiation (2–8 Gy, single dose) followed by MTT, Caspase 3/7 activity, γH2AX/53BP1 foci assays, AnnexinV staining, cell cycle analysis, 3D colony forming assays and Western blotting (cellular IAP1 (cIAP1) and cIAP2, Survivin, X-linked IAP (XIAP)).

Results

BV6 treatment decreased cell viability and significantly increased irradiation-induced apoptosis as analyzed by Caspase 3/7 activity, AnnexinV-positive and subG1 phase cells. While basal 3D clonogenic survival was decreased in a cell line-dependent manner, BV6 significantly enhanced cellular radiosensitivity of all cell lines in a concentration-dependent manner and increased the number of radiation-induced γH2AX/53BP1-positive foci. Western blot analysis revealed a markedly reduced cIAP1 expression at 4 h after BV6 treatment in all cell lines, a substantial reduction of XIAP expression in SW480 and HT-29 cells at 24 h and a slightly decreased cIAP2 expression in HCT-15 cells at 48 h after treatment. Moreover, single or double knockdown of cIAP1 and XIAP resulted in significantly increased residual γH2AX/53BP1-positive foci 24 h after 2 Gy and radiosensitization relative to control small interfering RNA (siRNA)-treated cells.

Conclusion

The SMAC mimetic BV6 induced apoptosis and hampered DNA damage repair to radiosensitize 3D grown colorectal cancer cells. Our results demonstrate IAP targeting as a promising strategy to counteract radiation resistance of colorectal cancer cells.
Appendix
Available only for authorised users
Literature
1.
2.
Sauer R, Becker H, Hohenberger W, Rodel C, Wittekind C, Fietkau R, et al. Preoperative versus postoperative chemoradiotherapy for rectal cancer. N Engl J Med. 2004;351:1731–40.CrossRefPubMed
3.
Sauer R, Liersch T, Merkel S, Fietkau R, Hohenberger W, Hess C, et al. Preoperative versus postoperative chemoradiotherapy for locally advanced rectal cancer: results of the German CAO/ARO/AIO-94 randomized phase III trial after a median follow-up of 11 years. J Clin Oncol. 2012;30:1926–33.CrossRefPubMed
4.
Begg AC, Stewart FA, Vens C. Strategies to improve radiotherapy with targeted drugs. Nat Rev Cancer. 2011;11:239–53.CrossRefPubMed
5.
6.
Dubrez L, Berthelet J, Glorian V. IAP proteins as targets for drug development in oncology. Onco Targets Ther. 2013;9:1285–304.CrossRefPubMed
7.
Cheung CH, Huang CC, Tsai FY, Lee JY, Cheng SM, Chang YC, et al. Survivin - biology and potential as a therapeutic target in oncology. Onco Targets Ther. 2013;6:1453–62.PubMedCentralCrossRefPubMed
8.
Rodel F, Sprenger T, Kaina B, Liersch T, Rodel C, Fulda S, et al. Survivin as a prognostic/predictive marker and molecular target in cancer therapy. Curr Med Chem. 2012;19:3679–88.CrossRefPubMed
9.
Carmena M, Wheelock M, Funabiki H, Earnshaw WC. The chromosomal passenger complex (CPC): from easy rider to the godfather of mitosis. Nat Rev Mol Cell Biol. 2012;13:789–803.PubMedCentralCrossRefPubMed
10.
Sprenger T, Rodel F, Beissbarth T, Conradi LC, Rothe H, Homayounfar K, et al. Failure of downregulation of survivin following neoadjuvant radiochemotherapy in rectal cancer is associated with distant metastases and shortened survival. Clin Cancer Res. 2011;17:1623–31.CrossRefPubMed
11.
Flanagan L, Kehoe J, Fay J, Bacon O, Lindner AU, Kay EW, et al. High levels of X-linked Inhibitor-of-Apoptosis Protein (XIAP) are indicative of radio chemotherapy resistance in rectal cancer. Radiat Oncol. 2015;10:131.PubMedCentralCrossRefPubMed
12.
13.
Obexer P, Ausserlechner MJ. X-linked inhibitor of apoptosis protein - a critical death resistance regulator and therapeutic target for personalized cancer therapy. Front Oncol. 2014;4:197.PubMedCentralCrossRefPubMed
14.
LaCasse EC, Mahoney DJ, Cheung HH, Plenchette S, Baird S, Korneluk RG. IAP-targeted therapies for cancer. Oncogene. 2008;27:6252–75.CrossRefPubMed
15.
Varfolomeev E, Blankenship JW, Wayson SM, Fedorova AV, Kayagaki N, Garg P, et al. IAP antagonists induce autoubiquitination of c-IAPs, NF-kappaB activation, and TNFalpha-dependent apoptosis. Cell. 2007;131:669–81.CrossRefPubMed
16.
Vucic D, Dixit VM, Wertz IE. Ubiquitylation in apoptosis: a post-translational modification at the edge of life and death. Nat Rev Mol Cell Biol. 2011;12:439–52.CrossRefPubMed
17.
Chai J, Du C, Wu JW, Kyin S, Wang X, Shi Y. Structural and biochemical basis of apoptotic activation by Smac/DIABLO. Nature. 2000;406:855–62.CrossRefPubMed
18.
Samuel T, Welsh K, Lober T, Togo SH, Zapata JM, Reed JC. Distinct BIR domains of cIAP1 mediate binding to and ubiquitination of tumor necrosis factor receptor-associated factor 2 and second mitochondrial activator of caspases. J Biol Chem. 2006;281:1080–90.CrossRefPubMed
19.
Petersen SL, Wang L, Yalcin-Chin A, Li L, Peyton M, Minna J, et al. Autocrine TNFalpha signaling renders human cancer cells susceptible to Smac-mimetic-induced apoptosis. Cancer Cell. 2007;12:445–56.PubMedCentralCrossRefPubMed
20.
Bake V, Roesler S, Eckhardt I, Belz K, Fulda S. Synergistic interaction of Smac mimetic and IFNalpha to trigger apoptosis in acute myeloid leukemia cells. Cancer Lett. 2014;355:224–31.CrossRefPubMed
21.
Belz K, Schoeneberger H, Wehner S, Weigert A, Bonig H, Klingebiel T, et al. Smac mimetic and glucocorticoids synergize to induce apoptosis in childhood ALL by promoting ripoptosome assembly. Blood. 2014;124:240–50.CrossRefPubMed
22.
Chromik J, Safferthal C, Serve H, Fulda S. Smac mimetic primes apoptosis-resistant acute myeloid leukaemia cells for cytarabine-induced cell death by triggering necroptosis. Cancer Lett. 2014;344:101–9.CrossRefPubMed
23.
Berger R, Jennewein C, Marschall V, Karl S, Cristofanon S, Wagner L, et al. NF-kappaB is required for Smac mimetic-mediated sensitization of glioblastoma cells for gamma-irradiation-induced apoptosis. Mol Cancer Ther. 2011;10:1867–75.CrossRefPubMed
24.
O’Connor PM, Jackman J, Bae I, Myers TG, Fan S, Mutoh M, et al. Characterization of the p53 tumor suppressor pathway in cell lines of the National Cancer Institute anticancer drug screen and correlations with the growth-inhibitory potency of 123 anticancer agents. Cancer Res. 1997;57:4285–300.PubMed
25.
26.
27.
Dupoux A, Cartier J, Cathelin S, Filomenko R, Solary E, Dubrez-Daloz L. cIAP1-dependent TRAF2 degradation regulates the differentiation of monocytes into macrophages and their response to CD40 ligand. Blood. 2009;113:175–85.PubMedCentralCrossRefPubMed
28.
Hehlgans S, Petraki C, Reichert S, Cordes N, Rodel C, Rodel F. Double targeting of Survivin and XIAP radiosensitizes 3D grown human colorectal tumor cells and decreases migration. Radiother Oncol. 2013;108:32–9.CrossRefPubMed
29.
Reichert S, Rodel C, Mirsch J, Harter PN, Tomicic MT, Mittelbronn M, et al. Survivin inhibition and DNA double-strand break repair: a molecular mechanism to overcome radioresistance in glioblastoma. Radiother Oncol. 2011;101:51–8.CrossRefPubMed
30.
Eke I, Deuse Y, Hehlgans S, Gurtner K, Krause M, Baumann M, et al. beta(1)Integrin/FAK/cortactin signaling is essential for human head and neck cancer resistance to radiotherapy. J Clin Invest. 2012;122:1529–40.PubMedCentralCrossRefPubMed
31.
Hehlgans S, Eke I, Cordes N. Targeting FAK radiosensitizes 3-dimensional grown human HNSCC cells through reduced Akt1 and MEK1/2 signaling. Int J Radiat Oncol Biol Phys. 2012;83:e669–676.CrossRefPubMed
32.
33.
Feoktistova M, Geserick P, Kellert B, Dimitrova DP, Langlais C, Hupe M, et al. cIAPs block Ripoptosome formation, a RIP1/caspase-8 containing intracellular cell death complex differentially regulated by cFLIP isoforms. Mol Cell. 2011;43:449–63.PubMedCentralCrossRefPubMed
34.
Tenev T, Bianchi K, Darding M, Broemer M, Langlais C, Wallberg F, et al. The Ripoptosome, a signaling platform that assembles in response to genotoxic stress and loss of IAPs. Mol Cell. 2011;43:432–48.CrossRefPubMed
35.
36.
37.
Ohnishi K, Nagata Y, Takahashi A, Taniguchi S, Ohnishi T. Effective enhancement of X-ray-induced apoptosis in human cancer cells with mutated p53 by siRNA targeting XIAP. Oncol Rep. 2008;20:57–61.PubMed
38.
Sinclair WK, Morton RA. X-ray sensitivity during the cell generation cycle of cultured Chinese hamster cells. Radiat Res. 1966;29:450–74.CrossRefPubMed
39.
Stadel D, Cristofanon S, Abhari BA, Deshayes K, Zobel K, Vucic D, et al. Requirement of nuclear factor kappaB for Smac mimetic-mediated sensitization of pancreatic carcinoma cells for gemcitabine-induced apoptosis. Neoplasia. 2011;13:1162–70.PubMedCentralCrossRefPubMed
40.
Yang D, Zhao Y, Li AY, Wang S, Wang G, Sun Y. Smac-mimetic compound SM-164 induces radiosensitization in breast cancer cells through activation of caspases and induction of apoptosis. Breast Cancer Res Treat. 2012;133:189–99.CrossRefPubMed
41.
Eke I, Schneider L, Forster C, Zips D, Kunz-Schughart LA, Cordes N. EGFR/JIP-4/JNK2 signaling attenuates cetuximab-mediated radiosensitization of squamous cell carcinoma cells. Cancer Res. 2013;73:297–306.CrossRefPubMed
42.
Lee J, Cuddihy MJ, Kotov NA. Three-dimensional cell culture matrices: state of the art. Tissue Eng Part B Rev. 2008;14:61–86.CrossRefPubMed
43.
Qin Q, Zuo Y, Yang X, Lu J, Zhan L, Xu L, et al. Smac mimetic compound LCL161 sensitizes esophageal carcinoma cells to radiotherapy by inhibiting the expression of inhibitor of apoptosis protein. Tumour Biol. 2014;35:2565–74.CrossRefPubMed
44.
Chakravarti A, Zhai GG, Zhang M, Malhotra R, Latham DE, Delaney MA, et al. Survivin enhances radiation resistance in primary human glioblastoma cells via caspase-independent mechanisms. Oncogene. 2004;23:7494–506.CrossRefPubMed
Metadata
Title
The SMAC mimetic BV6 sensitizes colorectal cancer cells to ionizing radiation by interfering with DNA repair processes and enhancing apoptosis
Authors
Stephanie Hehlgans
Julius Oppermann
Sebastian Reichert
Simone Fulda
Claus Rödel
Franz Rödel
Publication date
01-12-2015
Publisher
BioMed Central
Published in
Radiation Oncology / Issue 1/2015
Electronic ISSN: 1748-717X
DOI
https://doi.org/10.1186/s13014-015-0507-4

Other articles of this Issue 1/2015

Radiation Oncology 1/2015 Go to the issue

Research

Gradient-based delineation of the primary GTV on FLT PET in squamous cell cancer of the thoracic esophagus and impact on radiotherapy planning

Research

Long term results of postoperative Intensity-Modulated Radiation Therapy (IMRT) in the treatment of Squamous Cell Carcinoma (SCC) located in the oropharynx or oral cavity

Research

Feasibility of accelerated partial breast irradiation with volumetric-modulated arc therapy in elderly and frail patients

Research

Prostate motion during radiotherapy of prostate cancer patients with and without application of a hydrogel spacer: a comparative study

Research

Determining appropriate timing of adaptive radiation therapy for nasopharyngeal carcinoma during intensity-modulated radiation therapy

Research

Mutant KRAS associated malic enzyme 1 expression is a predictive marker for radiation therapy response in non-small cell lung cancer