SOX9: A Novel Marker for Pancreatic Centroacinar Cell and Ductal Cell Differentiation
Stuti Shroff, Asif Rashid, Hua Wang, Matthew H Katz, Jeffrey E Lee, James L Abbruzzese, Jason B Fleming, Huamin Wang. University of Texas, MD Anderson Cancer Center, Houston, TX
Background: The function of the DNA binding protein SOX9 [SRY (Sex determining region Y)-box9] in chondrocyte, gonadal and neural crest differentiation has been well established. Recent studies from mouse models have implicated that SOX9 plays a role in pancreatic development. We therefore examined the expression of SOX9 in benign pancreatic tissue (BP) and different types of pancreatic neoplasms.
Design: We constructed tissue microarrays using archival tissue samples from 145 patients with pancreatic ductal adenocarcinoma (PDA), 39 patients with pancreatic neuroendocrine tumor (PEN), 23 patients with solid pseudopapillary neoplasm (SPN), 9 patients with acinar cell carcinoma (ACC) and their matched BP samples from 146 patients who underwent pancreatectomy at our institution. Benign pancreas and tumor were sampled in duplicate with a 1.0 mm punch from representative areas. Nuclear expression of SOX9 was evaluated by immunohistochemistry using a polyclonal antibody (1:2000, Millipore) and categorized as SOX9-negative (no staining in the tumor cells) or SOX9-positive (>20% staining in tumor cells). The nuclear expression of SOX9 was correlated with the clinicopathologic parameters.
Results: Nuclear expression of SOX9 was detected in the centroacinar cells and pancreatic ductal epithelial cells in 100% BP samples (146/146), 89.0% (129/145) PDAs, 2% (1/39) PENs, 11% (1/9) of ACCs and 0% (0/23) SPNs (P<0.05). No correlation between the nuclear expression of SOX9 and other clinicopathologic parameters were identified (P>0.05).
Conclusions: The expression of SOX9 in centroacinar and pancreatic ductal epithelial cells but not in acinar or endocrine cells of the pancreas suggests that SOX9 may have an important role in ductal differentiation. In addition, nuclear expression of SOX9 in PDA's may be a useful tool to distinguish it from challenging cases of SPT, PEN and ACC.
Tuesday, March 5, 2013 9:30 AM
Poster Session III # 211, Tuesday Morning