# Race-related host and microbe transcriptomic signatures in triple-negative breast cancer

## TL;DR

This study finds racial differences in tumor microbes and immune cells in triple-negative breast cancer, which may affect survival outcomes.

## Contribution

The study identifies race-related microbial and immune signatures in TNBC tumors and links them to survival differences.

## Key findings

- AA tumors had higher abundance of Hafnia and Cedecea, while EA tumors had more Erwinia.
- AA tumors showed higher Th1 cells, while EA tumors had higher M2 macrophages.
- High SPDYE2B gene expression was linked to Hafnia abundance and worse survival in AA patients.

## Abstract

Triple-negative breast cancer (TNBC) shows racial disparities, with higher incidence in women of African ancestry (AA) compared to European ancestry (EA). Meta-transcriptomic analysis of TNBC tumor tissues from AA (n = 17) and EA (n = 19) subjects revealed distinct microbial landscapes. Hierarchical clustering based on microbial transcripts separated samples into two groups predominantly defined by racial ancestry. Bacterial genera including Hafnia and Cedecea were more abundant in AA tumors, while Erwinia was higher in EA tumors. Cellular composition analysis by xCell revealed differences in immune cell populations, with AA tumors having higher Th1 cell abundance and EA tumors containing higher macrophage M2 cell abundance. Nonetheless, AA women with high M2 abundance experienced poorer disease-free survival (DFS) than EA women. Integrative analyses revealed that high expression of human SPDYE2B gene was associated with Hafnia abundance and decreased DFS, highlighting complex host-microbe interactions in TNBC patients.