MicroRNA-375 targets the 3-phosphoinositide-dependent protein kinase-1 gene in pancreatic carcinoma

Pancreatic carcinoma (PC) is an aggressive malignancy with one of the poorest mortality rates. It is the sixth leading cause of mortality from malignant disease in China and the fourth leading cause of cancer-related mortality in the United States. The poor outcome reflects the requirement for an improved understanding of the transcriptional control of oncogenic signaling pathways. 3-phosphoinositide-dependent protein kinase-1 (PDK1) is a potent oncogenic driver of PC. The present study aimed to elucidate the transcriptional regulation of microRNA (miR)-375-targeted PDK1. miR-375 is a putative target and, in the present study, was observed to be significantly downregulated in the tumor compared with non-tumor tissues from patients with PC (n=44). As determined by a luciferase reporter assay, the ectopic expression of miR-375 was identified to diminish the transcriptional activity of PDK1. Furthermore, immunoblotting revealed that miR-375 suppressed endogenous PDK1 protein levels. Functional assays showed that miR-375 was able to inhibit proliferation and promote apoptosis of the PC cells. miR-375 is a significant regulator of the PDK1 oncogene, suggesting that it may have a potential therapeutic role in the treatment of PC.