Expression of GRP78 protein in pancreatic ductal adenocarcinoma and intraductal papillary mucinous neoplasm.

323Background: Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis due to late detection, aggressive biology and resistance to chemotherapy. Markers for early detection of PDAC and mediators of chemoresistance are poorly understood. GRP78 is a major endoplasmic reticulum (ER) chaperone protein critical for protein quality control of the ER. Increased GRP78 expression promotes in vitro cancer cell survival, progression, and chemoresistance. This study aims to examine expression of GRP78 protein in PDAC and intraductal papillary mucinous neoplasm (IPMN) compared to normal pancreatic ducts using immunohistochemistry (IHC). Methods: The expression of GRP78 was assessed using IHC in 93 sections of formalin-fixed paraffin-embedded tissue: normal ducts (38), low grade IPMN (IPMN-LG, 26), high grade IPMN (IPMN-HG, 9), and PDAC (20). Immunostaining intensity of GRP78 protein was categorized as no or weak staining (0-1+) and strong staining (2-3+). Fisher’s exact test with two tails was performed using the...