Published in:
01-08-2005 | Original Paper
Transfection of thymidine phosphorylase cDNA to human hepatocellular carcinoma cells enhances sensitivity to fluoropyrimidine but augments endothelial cell migration
Published in: Journal of Cancer Research and Clinical Oncology | Issue 8/2005
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Purpose: To investigate the effects on sensitivity to fluoropyrimidine and endothelial cell (EC) migration by transfection with thymidine phosphorylase (TP) cDNA to a hepatocellular carcinoma (HCC) cell line SMMC-7721.
Methods: SMMC-7721 was transfected with pcDNA3.1/zeo (+) with human TP cDNA. TP mRNA expression was determined by RT–PCR. Sensitivity to fluoropyrimidine was determined by 3-[4,5-dimethylthiazol-2-yl]-2, 5-diphenyl-tetrazolium bromide (MTT) assay. Induction of EC migration was detected by Boyden chamber assay.
Results: The construction of pcDNA3.1/zeo(+)-TP was verified by digestion with restriction endonuclease Apa1. When comparison was made between SMMC-7721 cell clone transfected with pcDNA3.1/zeo(+)-TP (S-TP) and control clone transfected with pcDNA3.1/zeo(+) (S-vector), we found that TP mRNA expression level was much higher in S-TP, being 2.09±0.16 vs 0.48±0.06 in S-vector (P<0.01), sensitivity to 5′-deoxy-5-fluorouridine (5′-dFUrd, a prodrug of 5-fluorouracil) in S-TP was significantly enhanced compared with that in S-vector (IC50; 56.81±9.85 μmol/l vs 162.25±11.03 μmol/l, P<0.01), and the culture medium of S-TP possessed more potential to induce EC migration than that of S-vector (the number of ECs appearing on the outer surfaces of the membrane was 275±29 vs 122±35 per field, P<0.01).
Conclusion: Sensitivity to 5′-dFUrd could be enhanced by transfection with TP cDNA for SMMC-7721 cells. However, EC migration was also promoted at the same time. Therefore, transfection with TP alone might have no potential to enhance anti-tumoral effects of fluoropyrimidine in HCC.