MiR-139-5p/SLC7A11 Inhibits the Proliferation and Migration of Pancreatic Carcinoma via PI3K/Akt Signaling Pathway

Abstract

Objective: Pancreatic carcinoma (PANC) is one of the important aggressive cancers, with deficiency in effective therapeutics. Studies have unveiled that miR-139-5p expression is significantly downregulated in other types of cancers. However, the functions and mechanisms of miR-139-5p in PANC remain unclear. 
 Methods: Bioinformatic analysis was performed to analyze the differentially expressed genes in the TCGA database. PANC cell line with overexpressed miR-139-5p and Solute Carrier Family 7, Member 11 (SLC7A11) was established, and has been used to detect cell proliferation, migration, invasion and colony formation in PANC. Subsequently, bioinformatic analysis and luciferase assay were performed to confirm that SLC7A11 was a target gene of miR-139-5p. Xenograft mouse model was used to investigate the role of miR-139-5p in PANC tumorigenicity. 
 Results: Through bioinformatic analysis, miR-139-5p was predicted to regulate phosphatidylinositol signaling pathway by targeting SLC7A11. MiR-139-5p was found to be lowly expressed in PANC tissues, while SLC7A11 was highly expressed. Low expression of miR-139-5p and high expression of SLC7A11 were positively associated with poor clinical outcomes. PANC cell proliferation, migration, and invasion could be inhibited by miR-139-5p overexpression and could be promoted by SLC7A11 overexpression. MiR-139-5p could regulate the protein expression level of PI3K and Akt associated with phosphatidylinositol signaling pathway could be by inhibiting the expression of SLC7A11. MiR-139-5p overexpression could suppress PANC tumor growth and the expression of SLC7A11, p-PI3K, p-Akt in tumor tissues. Therefore, the inhibiting effect of miR-139-5p to PANC cell proliferation, invasion and migration, at least, was partly due to its inhibiting effect on SLC7A11 expression. 
 Conclusion: These results demonstrated a novel role of miR-139-5p/SLC7A11 in PANC and provided potential prognostic predictors for PANC patients.