The Experimental Study On The Regulation Of CLIC1 And Gastric Cancer Metastasis By Long Non-coding RNA CCAT1

Objectives:To study the expression of long non-coding RNA(Inc RNA)colon cancer-related transcription factor 1(CCAT1)in gastric cancer and its relationship with the clinicopathological characteristics of gastric cancer patients,and to observe the expression changes of CLIC1 by constructing a CCAT1 down-regulating plasmid,and to analyze the possible regulatory mechanisms.Methods:(1)The expression level of lncRNA CCAT1 in 20 gastric cancer tissues was measureed by PCR(RT-qPCR).(2)Combine the expression level of CCAT1 with the clinicopathological characteristics of gastric cancer patients,and analyze the factors that affect the expression of CCAT1 in gastric cancer patients.(3)Real-time fluorescence quantitative(RT-qPCR)and Western-blot(Western-blot,WB)were used to detect the expression of CLIC1 in gastric cancer tissue and its corresponding adjacent tissues.(4)The expression of CCAT1 gene was down-regulated in gastric cancer cell line SGC-7901,the expression of CLIC1 was detected,and the relationship between CCAT1 and CLIC1 was analyzed.Results:(1)The expression of CCAT1 is elevated in gastric cancer tissues.(2)The high expression of CCAT1 is related to the tumor size(P=0.003),depth of invasion(P=0.004),and CEA(P=0.033)in gastric cancer patients.The tumor size can be used as an independent risk factor for the expression level of CCAT1 in gastric cancer tissue.(3)Kaplan-Meier Plotter database survival analysis results show that patients with high CCAT1 expression have a shorter survival time and a worse prognosis.(4)The expression of CLIC1mRNA and CLIC1 protein in gastric cancer tissues is higher than thatin adjacent tissues,and the expression level of CLIC1 is positively correlated with the expression of CCAT1.(5)After using the plasmid pc-CCAT1 as a vector to down-regulate the expression of CCAT1,the expression of CLIC1 was significantly reduced,suggesting that CLIC1 may bea downstream regulatory gene of CCAT1.Conclusions:(1)CCAT1 is highly in gastric cancer tissues,and is positively correlated with tumor size,depth of invasion,and CEA level.K-M showed that high CCAT1 level patient had shorter survival.The results suggested that CCAT1 may be involved in the occurrence of this kind of cancer.(2)The expression of CLIC1 is up-regulated in gastric cancer tissues and is positively correlatedwith the expression of CCAT1.When the expression of CCAT1 is down-regulated,the expression of CLIC1 also decreases.This indicates that CCAT1may be a regulatory gene of CLIC1.