MLPH regulates EMT in pancreatic adenocarcinoma through the PI3K-AKT signaling pathway

Pancreatic adenocarcinoma (PAAD) is an extremely malignant tumor, and most patients develop postoperative metastases. Melanophilin (MLPH) is involved in the progression of various tumors, but its molecular mechanisms and role in pancreatic cancer progression are unknown. In this study, differential MLPH expression in cancer tissues and the adjacent tissues was evaluated using the Gene Expression Profiling Interaction Analysis 2 (GEPIA 2) and Human Protein Atlas (HPA) databases. The role of MLPH in PAAD proliferation, invasion, and migration in vitro was explored via clone formation, Cell Counting Kit-8 assay, Transwell assay, and western blot. The in vivo validation of function was performed using a metastatic nude mouse model. The result showed that the pancreatic cancer tissues had significantly higher MLPH expression levels than the noncancerous pancreatic tissues. MLPH expression changes were related to PAAD cell proliferation, invasion, and migration. The western blotting demonstrated that PAAD cells had reduced Epithelial-mesenchymal transition (EMT)-related marker expression. Furthermore, overexpressing MLPH enhanced cell proliferation, migration, and invasion, and increased EMT-related marker expression. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that the molecular mechanism underlying the effect of MLPH on PAAD was significantly related to the PI3K-AKT pathway. LY294002 blocked the MLPH overexpression-mediated enhanced cell invasion and migration and inhibited EMT-associated marker expression. Conversely, 740Y-P reversed the inhibitory effects of MLPH downregulation and led to cell migration, invasion, and EMT. MLPH regulated EMT to mediate PAAD cell invasive migration through the PI3K-AKT pathway. The results indicated that MLPH is a possible target for blocking PAAD metastasis.