Abstract A102: Secreted frizzled related-protein 2 is prognostic for survival in pancreatic cancer

Abstract

Abstract INTRODUCTION: Secreted frizzled-related protein 2 (SFRP2) is overexpressed in several tumor types and blocks tumor apoptosis, increases angiogenesis, and promotes T-cell exhaustion. It has also been shown to be associated with fibrosis in non-neoplastic pathologies. We hypothesize SFRP2 is prognostic for survival and associated with PDAC fibrosis and mesenchymal transformation. METHODS: SFRP2 gene expression and protein levels in patients with PDAC were analyzed using NCI’s The Cancer Genome Atlas (TCGA) data and data from resected tumors analyzed for protein levels by western blot. Disease free survival (DFS) and overall survival (OS) were analyzed using Kaplan Meier test. The association of stroma content and SFPR2 RNA expression in human PDAC was studied using Spearman correlation between the ESTIMATE algorithm stromal score and TCGA data. The GEPIA tool was used to compare SFRP2 mRNA levels between PDAC and normal pancreas tissue. Immunohistochemistry (IHC) for SFRP2 in KPC PDAC tumors were correlated with fibrosis stains Picrosirus red and Massone trichome. The role of SFRP2 in mesenchymal transformation was assessed by western blot in fibroblasts. RESULTS: TCGA RNAseq analysis of SFRP2 expression showed highest SFRP2 mRNA levels in pancreatic cancer out of 32 cancer types. GEPIA analysis of PDAC (n=179) and normal pancreas (n=177) mRNA data showed higher levels of SFRP2 mRNA in PDAC compared to normal pancreas (p<.01). High SFRP2 mRNA levels were associated with decreased disease-free survival hazard ratio = 2.6; p=0.0097). PDAC tissue showed higher SFRP2 protein compared to matched normal-adjacent tissue (n=24, p=0.0003). High SFRP2 expression was associated with decreased OS (p=0.0158. The ESTIMATE stromal score correlated with SFRP2 expression in human PDAC (Spearman correlation coefficient 0.81). Fibrosis levels in KPC PDAC tumors correlated with SFRP2 IHC (Spearman correlation coefficient 0.75). Fibroblasts treated with SFRP2 and TGFβ showed higher mesenchymal markers compared to untreated control. CONCLUSIONS: SFRP2 is increased in PDAC, associated with tumor fibrosis, and prognostic for survival. SFRP2 is a novel therapeutic target in PDAC. Citation Format: Lillian Hsu, Julie Siegel, Patrick Nasarre, Rupak Mukherjee, Meghan Gormley, Bailey Richardson, Jordan Morningstar, Imran Khan, Eleanor Hilliard, John O’Bryan, Krist Helke, Laura Spruill, Nathan Dolloff, Nancy Klauber-Demore. Secreted frizzled related-protein 2 is prognostic for survival in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr A102.