Summary Although bacteria have been detected in hepatocellular carcinoma (HCC), the low microbial biomass has hindered isolation of viable intratumoral strains and evaluation of their functional relevance. Intratumoral microbiota profiling by 5R 16S rRNA sequencing, together with a stringent contamination-controlled workflow, identified enrichment of Staphylococcus in advanced-stage (Barcelona Clinic Liver Cancer BCLC C) HCC and enabled isolation of a viable S. epidermidis strain, GX3-2, from HCC tissue. GX3-2 promoted HCC cell proliferation and migration in vitro and was associated with accelerated xenograft growth in a pilot intratumoral inoculation model. Multi-omics analyses linked GX3-2 to distinct metabolic features, including adenosine and 2-phenylethylamine (2-PEA), together with host transcriptional programs related to cell cycle and epithelial-mesenchymal transition. These findings provide proof-of-concept evidence that a tumor-derived S. epidermidis isolate may modulate malignant phenotypes in HCC.
Yang et al. (Wed,) studied this question.