A novel prognostic marker and immunogenic membrane antigen: prohibitin (PHB) in pancreatic cancer

Previous study, using immunoblotting with IgG and membrane proteins, identified prohibitin (PHB) as a potential immunogenic membrane antigen. Now, investigate PHB expression and biological functions in pancreatic cancer.

PHB expression was analysed in PDAC cell lines, normal pancreas tissues, cancer tissues, PDAC patient sera and healthy volunteer sera using QRT-PCR, Western blotting, IHC, and ELISA, and a survival analysis and a COX regression analysis were performed. Low and high PHB expression levels were accomplished using RNA interference technology and gene transfer techniques. Cell proliferation, migration, and invasion, apoptosis-related proteins were assessed 48 h after transfection.

PHB was generally expressed in the 8 tested PDAC cell lines. PHB was significantly increased in PDAC tissues and negatively correlated with overall survival (p < 0.01). PHB was an independent prognostic factor in PDAC (p < 0.01). PHB was increased in PDAC patient sera (p < 0.01). siRNA-PHB decreased cell growth, migration and invasion. However, PHB overexpression resulted in the opposite effects. Western blotting and Flow cytometric analysis revealed apoptosis inhibition in siRNA-PHB PDAC cells.

PHB plays a key role in modulating the malignant phenotype and apoptosis induction, which may be a novel prognostic predictor and a candidate for targeted therapy against PDAC.