Functional Characterization of miR-216a-5p and miR-125a-5p on Pancreatic Cancer Stem Cells.

Pancreatic ductal adenocarcinoma (PDAC) is the third leading cause of cancer-related death. Its poor prognosis is closely related to late-stage diagnosis, which results from both nonspecific symptoms and the absence of biomarkers for early diagnosis. MicroRNAs (miRNAs) exert a regulatory role in numerous biological processes and their aberrant expression has been found in a broad spectrum of diseases, including cancer. Cancer stem cells (CSCs) represent a driving force for PDAC initiation, progression, and metastatic spread. Our previous research highlighted the interesting behavior of miR-216a-5p and miR-125a-5p related to PDAC progression and the CSC phenotype. The present study aimed to evaluate the effect of miR-216a-5p and miR-125a-5p on the acquisition or suppression of pancreatic CSC traits. BxPC-3, AsPC-1 cell lines, and their CSC-like models were transfected with miR-216a-5p and miR-125a-5p mimics and inhibitors. Following transfection, we evaluated their impact on the expression of CSC surface markers (CD44/CD24/CxCR4), ALDH1 activity, pluripotency- and EMT-related gene expression, and clonogenic potential. Our results show that miR-216a-5p enhances the expression of CD44/CD24/CxCR4 while negatively affecting the activity of ALDH1 and the expression of EMT genes. MiR-216a-5p positively influenced the clonogenic property. MiR-125a-5p promoted the expression of CD44/CD24/CxCR4 while inhibiting ALDH1 activity. It enhanced the expression of Snail, Oct-4, and Sox-2, while the clonogenic potential appeared to be affected. Comprehensively, our results provide further knowledge on the role of miRNAs in pancreatic CSCs. Moreover, they corroborate our previous findings about miR-216a-5p's potential dual role and miR-125a-5p's promotive function in PDAC.