Abstract C132: Fusobacterium nucleatum in colorectal carcinoma and expression of multiple immune checkpoint molecules on T cells

Background: Fusobacterium nucleatum (Fn) appears to play a role in colorectal cancer carcinogenesis through suppression of antitumor immune response. This study aims to characterize immune-related signatures, including the expression of multiple immune checkpoint molecules in tumor-infiltrating T cells. Methods: We measured Fn DNA by quantitative PCR in a total of 155 colorectal cancer tissues. Gene expression profile was studied using microarray technology to determine the consensus molecular subtypes (CMS) and immune-related signatures using CIBERSORT and Gene Set Enrichment Analysis (GSEA), respectively. Expression of immune checkpoint molecules (PD-1, TIM-3, and TIGIT) on CD8+ cytotoxic T cells and the ratio of FOXP3-CD4-/FOXP3+CD4 were examined using multicolor flow cytometric analysis. Results: All patients had stage III disease underwent curative surgery. Fn infection was observed in 43% of patients and was associated with recurrence (Fisher’ exact test, P=0.002) and decreased overall survival (log-rank test, P Citation Format: Han Sang Kim, Wonkyu Kim, Chang Gon Kim, Jinseon Yoo, Soonmyung Paik, Eui-Cheol Shin, Tae-Min Kim, Hoguen Kim, Joong Bae Ahn. Fusobacterium nucleatum in colorectal carcinoma and expression of multiple immune checkpoint molecules on T cells [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr C132. doi:10.1158/1535-7163.TARG-19-C132