MiR-192 Reverses Cisplatin Resistance Of Human Gastric Cancer Cell Lines By Targeting ERCC3 And ERCC4

Objective The malignancies of stomach is a common disease in clinical diagnosis. In the early stage,gastric cancer is asymptomatic manifestation,so ti is often found at advanced stages,chemotherapy is essential to the most patients who are in advanced stages of gastric cancer.chemotherapeutic regimen in gastric cancer now we often choose is cisplatin-based chemotherapy,the acquisition of chemo-resistance is a major clinical obstacle to the successful treatment of gastric cancer.Currently,to investigate the mechanism of resistance, reversal of platinum-resistant is very hot. A number of studies demonstrated that nucleotide excision repair( or nucleotide excision repair, NER) is an important cause of acquired resistance to cisplatin[15]. The abnormal expression of micro RNAs(mi RNAs) could modulate cisplatin resistance of gastric cancer cells by multiple cell signaling pathways.Recent evidence indicated that mi RNA-192 was found to be resume the sensitivity of Hep G2.2.15 cells to cisplatin inhibiting nucleotide excision repair by targeting ERCC3 and ERCC4[16].It showed that mi RNA-192 may act as a promising therapeutic target for improvement of responsiveness to chemotherapy in liver cancer. However, it remains unclear whether mi RNA-192 can regulate cisplatin resistance in gastric cancer by nucleotide excision repair pathway,it is a problem worth to study.Methods Single cell gel electrophoresis(SCGE) was used to measure the level of DNA damage and repair in gastric cancer cell line SGC-7901 and gastric cancer cisplatin resistance cell line SGC-7901/DDP by observing the tail length.mi R-192 expression level in Gastric cancer cell line(SGC-7901) and cisplatin-resistant cell line(SGC-7901/DDP) were counted by quantitative real-time PCR,respectively.TheSGC7901 and SGC7901/DDP cells were transfected with the mimics or inhibitors of mi R-192 or negative control RNA(NC) by lipofectamine 2000.The expression of ERCC3 and ERCC4 in SGC-7901 and SGC-7901/DDP were discovered by Western blot, the apoptosis analysis was measured by flow cytometric apoptosis assay.The degree of migration of SGC-7901/DDP and SGC-7901 measured by cell wound scratch assay was used to estimate the ability of invasion.Results The level of DNA damage and repair in SGC-7901/DDP was higher than that in SGC-7901 according to the tail length of SCGE tests.The expression of mi R-192 was downregulated in SGC-7901/DDP in comparison with its parental cell lines SGC-7901,the SGC7901 were transfected with the mi R-192 mimics and NC, and the SGC7901/DDP transfected with the mi R-192 inhibitors and NC,the expression of ERCC3 and ERCC4 in SGC-7901 and SGC-7901/DDP were respectively upregulated and downregulated in comparison with their NC and veicle group;and the apoptosis rate in SGC-7901 and SGC-7901/DDP were respectively lower and higher than their NC and veicle group.Cell wound scratch assay showed that the migration of SGC-7901/DDP was weaker than that of SGC-7901.Conclusion Mi R-192 reverses cisplatin resistance in gastric cancer through adjusting NER pathway by targeting ERCC4 and ERCC3,the ability of DNA damage and repair in gastric cancer cisplatin resistance cell line SGC-7901 is enhanced significantly.The migration of SGC-7901/DDP is weaker than that of SGC-7901.