MiR-196a Overexpress In Liver Cancer And Promote Hepatoma Cell Proliferation

The diagnosis and treatment of liver cancer are still difficult problems to solvein clinic currently, Traditional conventional therapy surgery, radiotherapy andchemotherapy for moderate and advanced liver cancer patients have less thansatisfactory. Therefore, there is a pressing need for an effective therapy for liver cancer.With the continuous development of technology on tumor biological treatment，genetherapy appears to be a promising strategy for liver cancer treatment and gets moreand more attention. There are large number of research results show that microRNA（miRNA）is directly involved in the occurrence and development of liver cancerand is closely related to the pathological type,malignant degree and the grading andstaging of liver cancer on the feature of clinicopathologic. The above shows thatmiRNA could not only used to be markers on diagnostic and prognostic, but also as atarget for gene therapy of liver cancer. Of which miR-196a’s up-regulated expressingin various malignant tumor, such as pancreatic cancer, cervical cancer,breast cancer,stomach cancer,colon cancer, and by inhibit its target genes such as p27、FOXO1、ING5、netrin4and IκBα to promote the development and the progression ofmalignant tumors. However,there are few people have researches on the expressionlevels and regulation of downstream signaling pathways of miR-196a in liver cancer.Therefor，our researches want to study the expression of miR-196a in liver cancer toelaborate miR-196a’s biological function and the specific molecular mechanism inhepatoma cell proliferation.Objective: To detcet the expression level of miR-196a in liver cancer tissue andexplore the influence of miR-196a in the proliferation of Hep3B cells，then toclarify the role of miR-196a in the development of liver cancer. Methods: Collect twenty pairs of fresh surgical specimens of liver cancer andadjacent tissues，foster HepG2、Hep3B、SMMC-7721of live caner and L02ofnomal liver. Using qRT-PCR to detect the expression level of miR-196a in livercancer,adjacent tissues and nomal liver. Foster human Hep3B cells of liver cancer inthe logarithmic phase, divid them into control,miR-196a mimics and inhibitorsgroup, using MTT to analyze the viability of Hep3B cells,using qRT-PCR to detectethe expression of miR-196a in transfected Hep3B cells,using flow cytometry todetect the cell cycle, using qRT-PCR and Western blot to detect the expression ofFOXO1, one of the potential targets of miR-196a, using immunohistochemical toresearch the expression level of protein of FOXO1in liver cancer and adjacenttissues.Results: The expression of miR-196a were significantly upregulated in livercancer tissues as compared to the adjacent tissues (P<0.05). The expression ofmiR-196a were also upregulated in three hunan hepatoma cells SMMC-7721,HepG2and Hep3B, compared with human normal liver cell L-02(P<0.05). Incultured Hep3B cells, elevated miR-196a level promoted the cell proliferation,whereas suppression of miR-196a had the opposite effect(P<0.05). miR-196ainhibitors reduced Hep3B cell proliferation through blocking G1/S-phasetransition(P<0.05). Ectopic miR-196a expression suppressed FOXO1expression onprotein and mRNA level(P<0.05). miR-196a and FOXO1expression also showed asignificant negative correlation in liver cancer tissue.Conclusion: Our findings suggest that miR-196a promote hepatoma cellproliferation by targeting FOXO1. miR-196a may be a potential diagnosticbiomarker and therapeutic target for liver cancer.