The Mechanism Study Of Small Nucleolar RNA Host Gene 12(SNHG12) Promotes Metastasis In Hepatocellular Carcinoma

Part I The expression of SNHG12 in hepatocellular carcinoma and its clinical significanceObjective To investigate the expression level of SNHG12 in hepatocellular carcinoma and its clinical significance.Methods The expression levels of SNHG12 in HCC tissues were detected by RT-qPCR.Then the expression level of SNHG12 was further confirmed by In situ hybridization(ISH).RT-qPCR technique was used to analyze the expression difference of SNHG12 in different tumor diameter and different Edmondson-Steiner grades.The relationship between the expression level of SNHG12 and Edmondson-Steiner classification was analyzed by HE staining.Combined with the clinical and survival datas of HCC patients,we then analysed the correlation between the expression of SNHG12 with clinical and pathological data.Kaplan-Meier analysis showed the relationship between the SNHG12 expression level and survival rate and recurrence-free survival.Results Here,we report that SNHG12 is overexpressed in HCC tissues(2.94±0.88)compared with adjacent tissues(1.61±0.53),(P<0.01).HCC patients whose tumor diameter>5 cm had a higher SNHG12 level(4.02±0.28)than those tumor diameter≤5 cm(2.59±0.39).(P<0.01).HCC patients with a higher Edmonson-Steiner grade had a higher SNHG12 level.(P<0.01).SNHG12 was closely associated with tumor diameter(P=0.020),Edmonson-Steiner grade(P=0.015)and metastasis(P=0.031).Furthermore,Kaplan-Meier and log-rank test analyses suggested that HCC patients with high SNHG12 expression have shorter overall survival and high recurrence rate than those with low expression of SNHG12.(P<0.01).Conclusion SNHG12 maybe an oncogene in hepatocellular carcinoma and a potential warning indicator for poor prognosis of HCC patients.Part Ⅱ The molecular mechanisms of SNHG12 promoting hepatocellular carcinoma metastasisObjective To explore the possible molecular mechanism of SNHG12 promoting hepatocellular carcinoma metastasis.Methods The effects of SNHG12,Transwell invasion assay,MTT assay and cell scratch test on the invasion and growth and migration ability of hepatocarcinoma cells were observed by RNA interference technique in hepatocellular carcinoma cell line HepG2.Western blotting was used to detect the changes of key molecules in TGF-β/Smad pathway in SNHG12 knockdown HepG2 cells.Results Transwell cell invasion assay showed that the invasion ability of SNHG12 HepG2 was significantly lower than that of the control group(Fig.5B),the difference was statistically significant(p<0.05).MTT assay showed that the growth capacity of SNHG12 HepG2 was significantly decreased,the difference was statistically significant(p<0.05).Western blotting showed that the expression of vascular endothelial growth factor(VEGF),matrix metalloproteinase-2(MMP-2)and matrix metalloproteinase-9(MMP-9)were significantly higher than those of control group Significantly down.Cell scratches showed that the migration ability of silencing SNHG12 HepG2 cells was significantly lower than that of the control group.Western blotting showed that the expression of TGF-β1 was down-regulated and the expression of Smad7 was up-regulated by interfering with SNHG12 TGF-P/Smad pathway There was no significant change in total Smad2/3(T-Smad2/3),and the phosphorylation of Smad2/3(P-Smad2/3)was significantly down-regulated.Coclusion Upregulation of SNHG12 exhibits an oncogenic effect,Our research provides new views and landscapes to understand the complex signaling network in HCC,and potential new strategies for the prognosis and therapy of HCC.