Regulatory effect of miR-30b on migration and invasion of pancreatic cancer stem cells

Abstract

Objective: To detect the expression of micro RNA(miRNA, miR)-30bin pancreatic cancer stem cells (PCSCs) and to observe the regulatory effect of miR-30b on epithelial-mesenchymal transformation (EMT) process, migration and invasion of PCSCs. Methods: CD24, CD44 and EpCAM triple-positive PCSCs in pancreatic ductal adenocarcinoma(PDAC) cell line PANC-1 were sorted out by flow cytometry and the expression of Nanog and Oct4 were evaluated. The expression profile of miR-30 family in PCSCs and common cancer cells was analyzed, and the memberwith the most obvious differential expression was selected.miR-30b mimic was transfected into PCSCs and then RT-qPCR or Western Blot were performed to investigate the expression of EMT markers. The effect of miR-30b on the migration and invasion ability of PCSCs was detected by Transwell assay. Then, miR-30b agomir was transfected into PCSCs and inoculated in nude mice to study the effect of mir-30b on the tumorigenic ability. Results: PCSCs accounted for 4.52-8.09% of the total. The mRNA and protein levels of Oct4 and Nanog of PCSCswere significantly higher than those of PANC-1(P<0.001). The expression levels of miR-30b, c and d were significantly down-regulated, among which miR-30b was the most significant. After miR-30b overexpression in PCSCs, E-cadherin was significantly up-regulated (P<0.001), N-cadherin (P<0.001) and transcription factor Snail (P<0.001) were significantly down-regulated, while vimentin expression was not significantly changed. Transwell assay showed that both migration and invasiveness of PCSCs were significantly decreased after transfection (P<0.001). In vivo experiments, the tumor volume and weight of the nude mice injected with PCSCs overexpressing miR-30b were also significantly lower than those of the control group (P<0.01). Conclusions: CD24, CD44 and EpCAMtriple positive PCSCs in pancreatic cancer cells showed obvious stemness characteristics. miR-30b can reverse the EMT process of PCSCs, reduce their migration and invasion, and inhibit the tumorigenicity of PCSCs.