MiR-485-3p/MELK cascade mediates tumor progression in pancreatic cancer.

Pancreatic cancer remains one of the leading causes of mortality worldwide, largely due to the limitations of current clinical strategies for its treatment. As a result, identifying genetic alterations and potential therapeutic targets could offer new opportunities for improving the diagnosis and treatment of pancreatic cancer. The identification of differentially expressed genes (DEGs) and subsequent analyses, including signaling pathway enrichment, functional classification, and protein-protein interaction (PPI) network construction, were conducted using three public datasets: GSE32676, GSE71989, and GSE16515. Kaplan-Meier survival curves and receiver operating characteristic (ROC) curves were employed to investigate the correlation between hub genes and clinicopathological features in pancreatic cancer patients. Genetic alterations were analyzed using the CBioPortal web tool. Cell proliferation was assessed through CCK-8, colony formation, and EdU assays. Tumor migration, invasion, and angiogenesis were evaluated using transwell and tube formation assays, respectively. Protein and mRNA expression levels were measured via western blot analysis and qPCR assays. The subcutaneous xenografted nude mice models were generated to evaluate the potential effect of miR-485-3p/MELK cascade on tumor growth in vivo. Our analysis revealed that MELK expression is positively correlated with poor prognosis in patients with pancreatic cancer. The overexpression or knockdown of MELK significantly influences cell proliferation, tumor metastasis, and angiogenesis across various pancreatic cancer cell lines. Furthermore, we identified that miR-485-3p regulates MELK expression by directly targeting the MELK 3'UTR binding site in pancreatic cancer cells, which subsequently impacts tumor progression. Additionally, our findings demonstrate that the miR-485-3p/MELK cascade is closely associated with tumor progression in pancreatic cancer cells. Mechanistically, the miR-485-3p/MELK cascade promotes the phosphorylation of Akt to regulate pancreatic cancer cell progression, metastasis, and angiogenesis. Furthermore, overexpression of miR-485-3p inhibits the tumor growth induced by MELK overexpression in subcutaneous xenograft model. MiR-485-3p/MELK cascade may serve as a promising biomarker and therapeutic target for the diagnosis and treatment of pancreatic cancer.