Abstract P4-04-21: Host response to microbes found in the tumor microenvironment and healthy adjacent tissue

Abstract

Abstract Next generation sequencing methods have defined the bacterial microbiome in human breast milk and breast tissue, but the role of bacteria or their components in breast cancer has not been well defined. There is growing evidence in humans and animals that alterations of the gut microbiome may contribute to host susceptibility to cancer. However, the presence of bacteria at the site of the tumor microenvironment may also contribute to carcinogenesis (e.g. by promoting chronic inflammation) or immune surveillance (e.g. by stimulating antitumor pathways). Previously, we found that bacterial load in breast cancer tissue is inversely correlated to the progression of disease and that antimicrobial gene expression was comparatively higher in breast tissue from healthy subjects. Our investigation of the microbiome of breast tissue showed that overall microbiome signatures in breast cancer patients are similar when comparing their healthy adjacent tissue vs. the tumor tissue. However, our published preliminary studies did identify some differences in the abundance of specific bacteria between the two tissues. Here we investigated how those bacteria in healthy adjacent vs. tumor tissue may differentially stimulate cells found in breast tissue including breast ductal epithelium, adipocytes, and immune cells. Our preliminary data suggest that bacteria found in healthy adjacent vs. tumor tissue stimulate differential cytokine responses that may shape the local tumor microenvironment and beyond and may also contribute to local/regional immune surveillance. Citation Format: Marian Navarrete, Peter A Sieling, Delphine J Lee, Andrew W Chung. Host response to microbes found in the tumor microenvironment and healthy adjacent tissue [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P4-04-21.