Expression Of Long Non-Coding RNA FALEC In Hepatocellular Carcinoma And Its Effect On Cellular Biological Function

Objective:To investigate the expression of lncRNA FALEC in hepatocellular carcinoma cells and its effect on cell biological function.Methods:（1）Thirty-five pairs of cancer tissues and adjacent tissues diagnosed as hepatocellular carcinoma by hepatobiliary surgery in the Affiliated Hospital of Youjiang Medical College for Nationalities from June 2020 to October 2021 were collected.Five pairs were selected to analyze the lncRNA expression profiles of hepatocellular carcinoma tissues and adjacent normal tissues by using lncRNA-seq+smallRNA high-throughput sequencing technology.With P<0.01 and|log₂FC|>2 as the standards,the differentially expressed lncRNA and mRNA were screened.According to the relevant literature and sequencing results,candidate lncRNA were screened,and their Pearson correlation coefficients with differentially expressed mRNAs were calculated.The lncRNA-mRNA co-expression regulatory network was constructed by introducing Cytoscape.GO functional annotation and KEGG Pathway enrichment analysis of mRNA in co-expression network were performed.（2）qRT-PCR was used to detect the relative expression levels of candidate lncRNA in30 HCC tissues and their adjacent tissues,and to explore the correlation between the finally verified differential lncRNA expression levels and the clinicopathological parameters of HCC patients.Two independent samples T test was used to compare the differences between the two groups.SPSS 23.0 software and Graph Pad Prism 9.3 statistical software were used to analyze the data.（3）qRT-PCR was used to detect the expression of lncRNA FALEC in two hepatocellular carcinoma（Hep G2,SMMC7721）relative to normal liver cell LO2.SiRNA transfection technology was used to make lncRNA FALEC low expression in Hep G2 cells.The transfection efficiency was detected by qRT-PCR.After transfection,CCK8 method was used to detect the proliferation ability of Hep G2 cells,Transwell method was used to detect the invasion ability of Hep G2 cells,and scratch test was used to detect the migration ability of Hep G2 cells.The cell apoptosis and cell cycle of Hep G2 cells were detected by flow cytometry.Results:（1）According to the results of high-throughput sequencing,a total of 85 differentially expressed lncRNA and 357 differentially expressed mRNAs were screened.Six low-expression candidate lncRNA（USP30-AS1,SMIM2-AS1,MGC27382,FGF14-AS2,DRAIC and CCDC26）and four high-expression candidate lncRNA（FALEC,ELF3-AS1,C1orf220 and ASB16-AS1）were selected by bioinformatics technology.（2）The results of qRT-PCR showed that in HCC tissues,the expressions of FALEC and C1orf220 were significantly up-regulated（P<0.05）,and the expressions of SMIM2-AS1,DRAIC and CCDC26 were significantly down-regulated（P<0.05）.here is no significant correlation between their expression and clinicopathological parameters such as gender,age,tumor size and tumor numbers in HCC patients（all P>0.05）.K-M analysis showed that the survival time of the high expression group of FALEC and C1orf220 was significantly decreased（P<0.05）.（3）The relative expression level of lncRNA FALEC in HCC cell lines（Hep G2,SMMC7721）was significantly up-regulated（P<0.05）.The results of siRNA transfection experiment showed that after knocking down lncRNA FALE expression,the proliferation,migration and invasion abilities of Hep G2 cells were significantly decreased（P<0.05）.The proportion of apoptosis was significantly increased（P<0.05）,and the cell cycle was not significantly changed.Conclusion:In this study,241 differentially expressed mRNAs were up-regulated and116 down-regulated in HCC tissues,and 39 differentially expressed lncRNAs were up-regulated and 46 down-regulated.This study confirmed that lncRNA FALEC and C1orf220 were significantly up-regulated in HCC tissues（P<0.05）,and SMIM2-AS1,DRAIC and CCDC26 were significantly down-regulated（P<0.05）.Moreover,FALEC,C1orf220 and SMIM2-AS1 were closely related to the survival time of HCC patients.LncRNA FALEC is up-regulated in hepatocellular carcinoma cells.LncRNA FALEC can promote the proliferation,invasion,migration and inhibit apoptosis of hepatocellular carcinoma cells.LncRNA FALEC is expected to become a new molecular marker for the diagnosis and treatment of hepatocellular carcinoma.