The molecular mechanism of miR-34a targeting on regulating c-MET expression in promoting pancreatic carcinoma and its clinical relevance / 中华胰腺病杂志

ABSTRACT

Objective To detect miR-34a expression in pancreatic cancer tissue and BxPC3 cells,determine the target genes and analyze the correlation of the expression of miR-34a and its target genes with clinicopathological parameters in pancreatic cancer as well as the influence on the proliferation and migration abilities of BxPC3 cells.Methods c-MET 3'UTR dual-luciferase reporter vectors cloned wild-type and mutant c-MET 3'UTR to validate that c-MET was the target gene of miR-34a,respectively.Liposome was used to establish miR-34a overexpressing BxPC3 cells (miR-34a group) and c-MET downregulating BxPC3 cells (c-METsi group).qPCR,Western blot and IHC was used to measure the mRNA and protein expression of miR-34a and c-MET.The cell viability and migration ability of miR-34a overexpressing BxPC3 cells was assessed by CCK-8 and transwell assay.Results In miR-34a group,the 3'UTR of wild-type c-MET was obviously downregulated compared with that of control group [(65.00 ± 4.04) ％ vs 100％,P =0.00131)],but no statistical difference was found between two mutant groups,which proved that c MET was the target gene of miR-34a.The expression level of miR-34a was significantly down-regulated in cancer tissues compared to adjacent normal tissues by an average fold change of 1.92,and the difference was statistically significant (P =0.003).Compared with control group,c-MET mRNA and protein expression was obviously decreased in miR-34a group (0.045 ±0.003 vs 0.085 ±0.001,0.400±0.058 vs 1.133 ±0.120).After 4-day culture,the cell viability of miR-34a group and c-METsi group was obviously decreased (P =0.0012;P =0.0001),the transmembrane cells was also obviously decreased(231 ± 12 vs 351 ± 16,P =0.0039;259 ±7 vs 351 ± 16,P=0.0066),and the differences were statistically significant.miR-34a overexpression and c-MET positively expression in pancreatic cancer were significantly associated with TNM stage and tumor differentiation (P ＜0.001),and the expression of c-MET negatively correlated with miR-34a (P ＜0.001).Conclusions miR-34a was lowly expressed in pancreatic cancer,and its tumor suppressive activity may be partly through inhibiting c-MET.Overexpressing miR-34a or inhibiting c-MET may be new targets for the diagnosis and treatment of pancreatic cancer.