Abstract 1607: Versican status in the tumor microenvironment heterogeneously impacts immune infiltration and inflammatory pathway expression

Background: Versican (VCAN) and its proteolysis product, Versikine (Vkine), have been shown to regulate CD8+ T-cell infiltration in cancers. Here, we evaluate the impact of VCAN proteolysis and accumulation on immune infiltration and immune-related pathway expression across cancer types. Methods: RNA expression (Z-score) signatures of VCANhi/ADAMTS4hi/TIMP3lo and VCANhi/ADAMTS4lo/TIMP3hi were used to identify VCAN proteolytic predominant (VPP) and weak (VPW) cohorts, respectively, from TCGA Pan-cancer Atlas datasets. Gene-set enrichment analysis was performed between VPP and VPW cohorts for each cancer type. 10 tissue microarrays (TMAs, UW Carbone Cancer Center Translational Science Biocore and TissueArray.com) were used to evaluate VCAN, Vkine, and CD8+ tumor infiltrating lymphocytes (TILs) by immunohistochemistry (IHC). VCAN and Vkine stromal intensity was scored from 0-3+. Cancers were categorized by IHC as VPP (VCAN low, Vkine high), VVL (VCAN low, Vkine low), and VPW (all others). CD8+ TILs were quantified per high-powered field (HPF). Results: Patients (n = 4664) were evaluated across 9 cancer types [breast, esophageal (EsC), gastric, kidney (KC), lung, melanoma, endometrial (EnC), bladder (BlC), and colorectal (CRC)], of which 400 were VPP or VPW. In ≥ 6 cancer types with VPP status, E2F targets and TNFα signaling via NFκB were enriched in (q < 0.001). In ≥ 2 cancer types with VPW status, myogenesis, coagulation, IFNα response, and epithelial mesenchymal transition were enriched (q < 0.05). IL6 (average log2 fold change 2.33), CSF3 (2.26), CXCL2 (1.76), CXCL3 (1.71), CXCL1 (1.47), CXCL8 (1.42) were upregulated across all VPP groups. SPP1 (0.96), PPP1R3C (0.95), and COMP (0.84) were upregulated across most VPW groups. IHC was performed on BlCs, KCs, EsCs, EnCs, triple-negative breast cancers (TNBCs), non-TNBCs, pancreatic ductal adenocarcinomas (PDACs), non-small cell lung cancers, and mismatch repair deficient (dMMR) and proficient (pMMR) CRCs. The most prevalent phenotype was VPP for EnCs (46.3%) and EsCs (52.0%), VPW for TNBCs (63.9%), pMMR CRCs (64.8%), PDACs (80.7%) and non-TNBCs (84.5%), and VVL for BlCs (78.6%) and KCs (85.9%). There were 0 VPP PDACs. CD8+ TILs were higher in VPP than VPW KCs (VPP average 16.3 CD8+ TILs/HPF = 16.3, VPW 13.7), EsC (39.9, 16.8), EnC (13.8, 9.8), dMMR CRC (31.5, 3.1), pMMR CRC (16.4, 2.2), and TNBC (37.0, 7.3). Cancers with < 5 average CD8+ TILs/HPF included VPW dMMR CRCs (3.1), pMMR CRCs (2.2), and PDACs (0.7) as well as VVL PDACs (2.9) and VPP non-TNBCs (4.5). Conclusion: VCAN proteolysis is associated with CD8+ TIL abundance, especially in EsCs, EmCs, dMMR and pMMR CRCs, and TNBCs, and expression of inflammatory genes and pathways. Further insight into VCAN prevalence and interactions with inflammatory pathways and other TME components is necessary to establish its potential as a pan-cancer biomarker for immunotherapy response. Citation Format: Ruchi Shah, Sean G. Kraus, Somak Chaudhuri, Elizabeth L. Field, Cheri A. Pasch, Katherine A. Johnson, Dustin A. Deming. Versican status in the tumor microenvironment heterogeneously impacts immune infiltration and inflammatory pathway expression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 1607.