Chemotherapy resistance (congenital or acquired) is one of the principal challenges for the treatment of pancreatic carcinoma. Recent evidence has demonstrated that epithelial to mesenchymal transition (EMT) is associated with chemoresistance in pancreatic carcinoma cells. However, the molecular mechanism underlying the development of chemoresistance remains unknown, and limited therapeutic options are available. Therefore, to anticipate individual chemosensitivity or acquired chemoresistance for patients with pancreatic carcinoma, predictive biomarkers are urgently required. Extensive evidence suggests that microRNAs (miRNAs) serve a crucial role in regulating EMT. The aim of this study was to examine the potential role of miRNA (miR)‑200b and miR‑301 in predicting the chemo‑responses to treatment for pancreatic carcinoma. The present results demonstrate that miR‑200b expression predicted chemo‑sensitivity and may have potential as a biomarker. In six different pancreatic carcinoma cell lines (Capan‑1, Capan‑2, Panc‑1, MIAPaCa‑2, BxPC‑3 and PL45 cells), the expression of miR‑200b correlated positively with chemosensitivity. Moreover, the enhanced expression of miR‑200b increased chemosensitivity and induced mesenchymal to epithelial transition. Conversely, miR‑301 modulated gemcitabine resistance and induced EMT through the downregulation of cadherin 1 expression. In addition, gemcitabine‑resistant cells (Capan‑2 and Panc‑1) exhibited upregulated miR‑301 expression and downregulated gemcitabine‑induced apoptosis. In summary, these two miRNAs may serve roles as biomarkers in pancreatic carcinoma, miR‑200b expression may predict chemosensitivity, and elevated miR‑301 expression may have potential applications in the prediction of acquired gemcitabine resistance.
Keywords: pancreatic cancer; microRNA-301; microRNA-200b; gemcitabine resistance.