Phosphatase of regenerating liver-3-signal transducer and activators of transcription 3-miR-21 sighal pathway promotes proliferation and invasion of colon cancer cells

Abstract

Objective To explore the effect of phosphatase of regenerating liver-3-signal transducer and activators of transcription 3-microRNA-21 (PRL-3-STAT3-miR-21) signal pathway on proliferation and invasion of colon cancer cellsMethods We stablely transfected PRL-3 expressing plasmid and empty plasmid into LoVo colon cancer cells and established two cell lines:LoVo-PRL-3 and LoVo-VC.We used quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) to detect the expression of miR-21 in LoVo cells.We also performed transient transfection of PRL-3 into SW480 and CACO2 cells to validate the expression of miR-21.Western blotting was used to detect the effect of PRL-3 on the expression of STAT3.RNA interference was used to knocked down STAT3 in LoVo-PRL-3 cells,after that miR-21 expression was detected.Transient transfection of miR-21mimic into LoVo-VC cells or transient transfection of miR-21 inhibitor into LoVo-PRL-3 cells were performed to evaluate the proliferation and invasive ability of these cells by CCK8 proliferating assay and Transwell chamber assay.Results PRL-3 promoted proliferation of LoVo-PRL-3 cells at 72 h,96 h and invasion of LoVo-PRL-3 cells after 24 h compared with LoVo-VC cells (P＜0.01).In LoVo-PRL-3 cells,pSTAT3 and miR-21 were up-regulated.Knock-down of STAT3 mRNA decreased the expression of miR-21 (P ＜ 0.05).Over-expression of miR-21 promoted proliferation and invasion of LoVo-VC cells (P ＜ 0.01),while knocking down of miR-21 inhibited proliferation and invasion of LoVo-PRL-3 cells (P ＜ 0.05).Conclusion PRL-3-STAT3-miR-21 signal pathway promotes proliferation and invasion of colon cancer cells. Key words: Phosphatase of regenerating liver-3; Signal transducer and activators of transcription 3 ; MicroRNA-21