Differential Expression Of LncRNA SLCO4A1-AS1 In Colorectal Cancer And Its Relationship With Prognosis

Objective: Recently,a large number of studies have reported that lncRNA is involved in the development of human cancer.However,the function and mechanism of many lncRNAs in colorectal cancer(CRC)remains unclear.First,the differentially expressed lncRNAs were screened by two sets of CRC Gene Microarray data and high-throughput sequencing data.SLCO4A1-AS1 with up-regulated expression was selected as the follow-up study object.Secondly,the expression of SLCO4A1-AS1 in CRC tissues was verified by qRT-PCR and in situ hybridization experiments,and its correlation with clinicopathological parameters was analyzed.Finally,the function and mechanism of SLCO4A1-AS1 in CRC cells were investigated by cell function assay and Western Blotting assay.Method: 1.To construct differential expression profiles of lncRNA by Gene Microarray and high-throughput sequencing data,and the lncRNA with common differential expression was selected as the follow-up study object..2.Through the collection of 22 normal colorectal tissues and 43 CRC tissues,qRT-PCR was used to detect the expression of SLCO4A1-AS1 in CRC tissue samples,and its relationship with clinicopathological parameters was analyzed by in situ hybridization.3.Normal colon cell line NCM460 and 5 CRC cell lines were cultured.The expression of SLCO4A1-AS1 in CRC cell line and normal colon cell line NCM460 was analyzed by qRT-PCR..4.Two cell lines with high differential expression,HCT116 and SW480,were selected for siRNA silencing experiments.CCK-8,colony formation assay for cell proliferation;wound healing assay,transwell assay for cell migration and invasion.5.The effects of silencing SLCO4A1-AS1 on EGFR and MAP3K1 were studied by mRNA and protein levels by qRT-PCR and Western Blotting.Result: 1.Using NCBI to download two GEO datasets GSE32323 and GES39582 to screen for 18 commonly differentially expressed lncRNAs.By conbining the RNA sequencing GSE104836 datasetwith the commonly differentially expressed lncRNA obtained by the Gene Microarray,the 7 co-up-regulated and 5 co-down-regulated lncRNAs were furtherobtained.Based on literature research and preliminary experimental results,SLCO4A1-AS1 was finally selected as the lncRNA for the purpose of subsequent research.2.SLCO4A1-AS1 is highly expressed in CRC and is associated with clinical pathological parameters of CRC.By qRT-PCR,it was found that SLCO4A1-AS1 was significantly up-regulated in tumor tissues.The high expression of SLCO4A1-AS1 in CRC was also detected by in situ hybridization assay.The high expression of SLCO4A1-AS1 was closely related to the survival time T stage,TNM stage and OS of CRC patients(P<0.05).3.HT29,HCT116,SW620,SW480,LoVo five CRC cell lines and normal colon cell line NCM460 were used for qRT-PCR detection.It was found that SLCO4A1-AS1 was highly expressed in CRC cells.Targeting silencing of SLCO4A1-AS1 in CRC cells with siRNA significantly reduced the proliferation,migration and invasion of cells,and the mRNA and protein levels of EGFR and MAP3K1 were also down-regulated.Conclusion: 1.The expression of LncRNA SLCO4A1-AS1 was significantly increased in CRC tissues and correlated with T stage,TMN stage and OS.2.LncRNA SLCO4A1-AS1 may promote CRC proliferation,migration and invasion through the EGFR/MAPK pathway.