LncRNA PVT1 Regulates MiR-30d-5p And Its Mechanism Of Action In The Development Of Colon Cancer

Purpose Colon cancer is one of the most ordinary gastrointestinal cancer all over the world.It seriously affects people's health and life with high morbidity and mortality.In recent years,long non-coding RNAs(lncRNAs)have attracted more and more attention in the development of tumors.Plasmacytoma Variant Translocation 1(PVT1)is a known long non-coding RNA,which acts as an oncogene in a variety of tumors.Some studies have shown that PVT1 is highly expressed in colon canc er tissues and cell lines,but the mechanism of PVT1 is still unclear.This study intends to explore the regulatory mechanism of PVT1 on miR-30d-5p and its role in the occurrence and development of colon cancer,so as to provide theoretical basis for the search of new markers and therapeutic targets for colon cancer.Methods In this research,Real-time quantitative polymerase chain reaction(RT-qPCR) was used to perceive the level of PVT1 expression in human's normal colonic epithelial cells,colon cancer cell lines and 60 paired colon cancer and paracancer tissue samples.Moreover,the associations between PVT1 expression level and clinicopathological characteristics and patients' disease-free survival rate was evaluated.Then,the cell lines with knockdown of PVT1 were constructed,and the changes in the proliferation and invasion functions of colon cancer cells with knockdown of PVT1 were detected by CCK8,Colony Formation and Transwell assay.the expression of miR-30d-5p in colon cancer tissues and paracancer tissues was detected by RT-qPCR,and the expression level of miR-30d-5p in colon cancer cell lines were detected before and after knockdown of PVT1.Finally,The interaction between PVT1 and miR-30d-5p was verified by luciferase assay and RNA immunoprecipitation assay.Results In the research,PVT1 expression was significantly higher in tumor tissues than that in corresponding tissues,and was associated with lymph node metastasis,tumor stage and survival time of these patients.Moreover,the expression level of PVT1 in colon cancer cell lines was significantly higher than that in normal human colon epithelial cells,which promoted the growth and invasion of tumors in vitro.In addition,further experiments revealed that miR-30d-5p was a direct target of PVT1 and its expression in tumor tissues negatively correlated to PVT1 expression.Conclusions These results indicate that PVT1 could promote metastasis and proliferation of colon cancer via sponging miR-30d-5p,which may offer a new vision for interpreting the mechanism of colon cancer development.