The Effects Of STRAP On Migration,Invasion,Proliferation And Apoptosis Of SNU449 And HepG2 Hepatoma Cell Lines

Objective: To detect the expression of STRAP in HCC and explore its effects on migration and invasion,apoptosis and proliferation of SNU449 and HepG2 hepatoma cell lines.Methods:(1)48 pairs of tumor tissues and its corresponding non-tumor tissue were collected,which were diagnosed with HCC by pathological method and operated by the first affiliated hospital of Guangxi Medical University from 2017 to 2018.We detected the expression of STRAP in these by immunohistochemistry.The expression of STRAP in 180 cases of HCC and its corresponding paracancerous tissues in tissue microarray was detected by the same method,and the relationship between STRAP expression level and clinicopathological features and prognosis of patients was analyzed.(2)We detected the relative expression of STRAP in 9 liver cancer cell lines(HepG2,Hep3 b,MHCC97H,Huh7,SNU449,SNU182,MHCC97 L,SK-hep1,MHCC-LM3)and two normal liver tissues by Western blotting,and then used lentiviral-mediated technique to transfect the SNU449 cell line and HepG2 cell line,for constructing stably expressing knockdown or over-expressing cell lines.The construction efficiency of the two cell lines was tested by qRT-PCR.(3)Using cell clone formation assay,Transwell in vitro migration assay,CCK-8 cell proliferation assay and flow cytometry to detect the change of proliferation,migration and invasion of hepatocellular carcinoma cell lines after STRAP knockdown and over-expression.Results:(1)The expression level of STRAP in tumor was significantly higher than adjacent non-tumor tissues(P<0.05).Expression of STRAP in HCC was negatively correlated with pathological grade(P<0.05),and there was no significant correlation with the overall survival of patients after receiving surgical operation(P>0.05).(2)The expression levels of STRAP in HepG2,Hep3 b,MHCC97H,Huh7,SNU449,SNU182,MHCC97 L,SK-hep1 and MHCC-LM3 were significantly higher than it in normal liver tissue(P<0.05);the stable cell line with knockdown and over-expression was successfully constructed,and the relative expression of STRAP was significantly increased after over-expression of STRAP in HepG2 cell line(P<0.05),while SNU449 cell line the expression of STRAP was significantly decreased after STRAP knockdown(P<0.05).(3)After knocked down STRAP gene of SNU449 cell line,the results suggest that cell clone formation ability and Transwell migration and invasion was significant decreased(P<0.05).And the results of CCK-8 cell proliferation assay indicated that the proliferation of SNU449 cells decreased after knockdown of STRAP gene,while the proliferation of HepG2 cells increase after over-expression of STRAP gene(P<0.05);the results of flow cytometry showed that the apoptosis rate of SNU449 cells and HepG2 cells increased and decreased after knockdown and over-expression of STRAP gene,respectively(P<0.05).Conclusion:(1)The expression level of STRAP in liver cancer tissue is significantly higher than that its adjacent tissues.The expression of STRAP in HCC is negatively correlated with pathological stage,but there was no significant correlation with postoperative overall survival of patients with HCC;(2)Knockout of STRAP gene of SNU449 cell line can inhibit its colony forming,migration and invasion and proliferation ability,and promote cell apoptosis.(3)Over-expression of STRAP gene of HepG2 cell line can promote its proliferation ability and inhibit cell apoptosis,it acts as a pro-oncogene in hepatocellular carcinoma.