Single cell RNA seq of cells invaded by bacteria

Recently, there has been increasing awareness that human tumors contain significant amount of viable commensal microbiota. To unveil the mystery of intratumor bacteria in tumor progression, we performed the optimized 16S library preparation and found that a significant amount of intratumor bacteria predominantly residing in the tumor cell cytosol, which faithfully recapitulates the pattern of human breast cancer microbiota. To understand the crosstalk between this intracellular bacteria and tumor cell, we co-cultured the intratumor CFSE-labelled bacteria and PYMT cancer cells and sorted out the individual cells with and without bacteria to conduct single cell RNAseq. KEGG pathway analysis revealed that tumor cells invaded by bacteria specifically enriched the fluid shear stress pathway. Functional analysis suggested that tumor cells had a significantly reduced stress fiber intensity in vitro and increased colonization ability via intravenous injection after the invasion of bacteria. All these findings would open a new area of intratumor bacteria in cancer biology and cancer clinical.