Increased SOX9 Expression in Premalignant and Malignant Pancreatic Neoplasms
SOX9, a progenitor cell marker, is important for pancreatic ductal development. Our goal was to examine SOX9 expression differences in intraductal papillary mucinous neoplasms (IPMNs) and ductal adenocarcinoma (PDAC) compared with benign pancreatic duct (BP).
SOX9 expression was evaluated by immunohistochemistry performed on 93 specimens: 37 BP, 24 low grade (LG) IPMN, 12 high grade (HG) IPMN, and 20 PDAC. A linear mixed-effects model was used to compare the percentage of cells expressing SOX9 by specimen type. A separate linear mixed-effects model evaluated differences in SOX9 expression by staining intensity in pancreatic epithelial cells.
Nuclear SOX9 expression was detected in the epithelial cells of 98% HG IPMN, 93% LG IPMN, 83% PDAC, and 60% BP. Compared with BP, SOX9 was expressed from a significantly greater percentage of cells in LG IMPN, HG IMPN, and PDAC (p < 0.001 for each). BP and PDAC showed greater variability in SOX9 expression in epithelial cells compared with IPMNs which showed strong, homogenous SOX9 expression in almost all cells. Compared with BP, both LG and HG IPMN showed significantly greater SOX9 expression (p < 0.001 for each), but there was no significant difference in SOX9 expression between LG and HG IPMN (p > 0.05). PDAC had significantly higher expression of SOX9 compared with BP but significantly lower SOX9 expression compared with LG or HG IPMN (p < 0.001 for each).
IPMNs demonstrated the highest expression levels of SOX9. SOX9 expression in BP and PDAC demonstrated much more heterogeneity compared with the strong, uniform expression in IPMN.
Jennifer Gnerlich: Study concept and design; acquisition, analysis, and data interpretation; drafting of manuscript; critical revision of manuscript; study supervision. Xianzhong Ding: Acquisition, analysis, and data interpretation; drafting of manuscript Cara Joyce: Statistical analysis; acquisition, analysis, and data interpretation; drafting of manuscript; critical revision of manuscript. Kevin Turner: Study concept and design; acquisition, analysis, and data interpretation; drafting of manuscript; critical revision of manuscript. Christopher Johnson: Critical revision of manuscript and drafting of resubmission. Haiyan Chen: Acquisition, analysis, and data interpretation. Gerard Abood: Critical revision of manuscript. Sam Pappas: Study concept and design; critical revision of manuscript. Gerard Aranha: Study concept and design; acquisition, analysis, and data interpretation; critical revision of manuscript; study supervision; administrative and material support.
The authors do not have any disclosures to report.