Spatial meta-transcriptomics reveal intratumor bacterial association with lung cancer cells showing a distinct oncogenic signature.

8531 Background: The lung intratumor microbiome influences lung cancer tumorigenesis and treatment responses, but detailed data on the extent, location, and effects of microbes within lung tumors is missing, information needed to improve treatment outcomes and prognosis. Methods: To address this gap, we developed a novel spatial meta-transcriptomic method simultaneously detecting the expression level of 1,811 host genes and three microbe targets (16S rRNA, 28S rRNA and CMV). After rigorous validation, we analyzed the spatial meta-transcriptomic profiles of tumor cells, T cells, macrophages, other immune cells, and stroma in tumor samples from 12 patients with early-stage lung cancer. Results: Bacterial burden was significantly higher in tumor cells compared to T cells, macrophages, other immune cells, and stroma. This burden increased from tumor-adjacent normal lung and tertiary lymphoid structures to tumor cells to the airways, suggesting that lung intratumor bacteria derive from the latter route of entry. Expression of oncogenic β-catenin and epithelial-mesenchymal transition pathway genes was strongly correlated with bacterial burden, as were tumor subtypes, mutation profile, histology and smoking history. Conclusions: Intratumor bacteria were enriched with tumor cells and associated with multiple oncogenic pathways, supporting a rationale for reducing the local intratumor microbiome in lung cancer to optimize clinical outcomes. This research was supported in part by the Intramural Research Programs of the NCI and NIAID. Other funding sources included ASCO Young Investigator Award, SITC-AstraZeneca Immunotherapy in Lung Cancer (Early Stage NSCLC) Clinical Fellowship Award, NIH Bench-to-Bedside and Back Program (BtB), NCI R00 award (CA226400), Emerson Collective Cancer Research fund, Lung Cancer Research Foundation (LCRF) pilot grant and W.W. Smith Trust Foundation award. This study was approved by NCI institutional review board (NCT00242723 and NCT02146170) and Animal Use and Care Committee at the University of Pennsylvania (#806875).