Effect And Mechanism Of LncRNA LIMT On EGF/EGFR Signaling Pathway In Hepatocellular Carcinoma

ObjectiveTo investigate the effect and mechanism of long non-coding RNA LIMT(LncRNA LIMT,also known as LINC01089)on epidermal growth factor/epidermal growth factor receptor(EGF/EGFR)signaling pathway in HCC.MethodsBased on the Department of Hepatobiliary Pancreatology,People’s Hospital of Henan University,HCC tissues and corresponding paracancer tissue samples of 45 patients who underwent hepatocellular carcinoma resection from December 2020 to December 2021 with complete case data were collected and selected.Quantitative fluorescence reverse transcriptase polymerase chain reaction(q RT-PCR)was used to determine the expression levels of LncRNA LIMT in HCC tissue and its corresponding paracancer tissue specimens,and the differences of LncRNA LIMT expression in HCC tissue and paracancer tissue specimens were statistically analyzed by paired sample t test.Meanwhile,Chi-square test was used to analyze the relationship between LncRNA LIMT expression and clinicopathological features in HCC tissues,and independent sample T-test was used to analyze the differences in LncRNA LIMT expression between groups.Subsequently,LncRNA LIMT overexpression and silencing plasmids were constructed and transfected into human liver cancer cell lines LM-3 and Huh-7.Transwell assay,cell colony assay and protein western blotting assay were performed.To explore the interaction between LncRNA LIMT and EGF/EGFR signaling pathway in HCC and its specific mechanism.Results1.45 In HCC patient tissues,compared with paracancer tissues,the downregulation ratio of LncRNA LIMT in HCC cancer center tissues was 75.56%(34/45).2.The relative expression level of LncRNA LIMT in HCC central tissues was(0.85±0.04),and that in adjacent tissues was(1.25±0.07),the difference was statistically significant(t=3.63,P < 0.05).3.In HCC cancer center tissues,LncRNA LIMT expression was significantly correlated with the differentiation level of tumor tissues(P < 0.01)and whether there was a portal vein cancer thrombin(P <0.05).There was no significant correlation with gender,age,HBV/HCV infection,tumor size,serum AFP concentration and other factors(P > 0.05).In HCC tissues,the expression level of LncRNA LIMT in the highly differentiated group was higher than that in the poorly differentiated group,and the expression level of LncRNA LIMT in the group without portal vein cancer thrombus was higher than that in the group with portal vein cancer thrombus.4.Transwell assay and cell colony assay showed that LncRNA LIMT overexpressed in HCC LM-3 and Huh-7 cells inhibited the proliferation,migration and invasion of HCC cells,and had an inhibitory effect on the development of HCC.5.Transwell assay and cell colony assay showed no significant differences in the proliferation,migration and invasion of LncRNA Limt-overexpressed cells after EGF-stimulated HCC LM-3 and Huh-7cells compared with non-EGF-stimulated HCC cells.In HCC cells stimulated by EGF directly and transfected with blank plasmid,cell proliferation,migration and invasion were significantly enhanced,indicating that LncRNA LIMT overexpression inhibited the stimulation effect of EGF.6.In HCC LM-3 and Huh-7 cells,the expression of LncRNA LIMT was significantly down-regulated after EGF stimulation,while the activation of STAT3 was enhanced.In LncRNA LIMT overexpressed HCC cells,the activated STAT3 expression level was significantly lower than that in the HCC cells directly stimulated by EGF or transfected with blank plasmid after EGF stimulation.Conclusion1.LncRNA LIMT was lower expressed in HCC central tissues than in adjacent tissues.In HCC tissues,LncRNA LIMT expression was low in the poorly differentiated group and the group with portal vein cancer embolus.These findings suggest that LncRNA LIMT may inhibit the occurrence,migration and invasion of HCC.2.Overexpressed LncRNA LIMT inhibited the proliferation,migration and invasion of HCC.3.In HCC,EGF/EGFR signaling pathway may inhibit LncRNA LIMT through activation of STAT3,thus promoting proliferation,migration and invasion of HCC.Conversely,overexpressed LncRNA LIMT may inhibit the proliferation,migration and invasion of HCC by inhibiting the activation of EGF/EGFR signaling pathway.