MiR-130b Is a Prognostic Marker and Inhibits Cell Proliferation and Invasion in Pancreatic Cancer through Targeting STAT3

Accumulating evidence indicates that microRNAs (miRNAs) are aberrantly expressed in human cancer and contribute to the tumorigenesis, but their roles in pancreatic cancer are still largely unknown. In this study, our data showed that miR-130b was significantly downregulated in 52 pairs of pancreatic cancer tissues and five cell lines. Furthermore, the deregulated miR-130b was correlated with worse prognosis, increased tumor size, late TNM stage, lymphatic invasion and distant metastasis. Multivariate analysis showed that miR-130b expression was a significant and independent prognostic predictor for pancreatic cancer patients. Functional studies indicated that the overexpression of miR-130b dramatically suppressed the proliferation of pancreatic cancer cells both in vitro and in vivo, which could be attributed to the induction of apoptosis and cell cycle arrest at S phase. Meanwhile, an overexpressed miR-130b remarkably inhibited the invasive ability of pancreatic cancer cells. Moreover, the dual luciferase assay revealed that STAT3 was directly targeted by miR-130b, which was further confirmed by the inverse expression of miR-130b and STAT3 in pancreatic cancer samples. Our findings suggested that miR-130b might have a considerable potential in prognosis identification and application of therapy for pancreatic cancer.