Urinary Eubacterium sp. CAG:581 promotes non-muscle-invasive bladder cancer (NMIBC) development through ECM1/MMP9 pathway

Abstract Background: Increasing evidence points to the urinarymicrobiota as a possible key susceptibility factor for early-stage bladder cancer(BCa) progression. However, its underlying mechanism interpretation is often insufficient, given that various environmental conditions have affected the composition of urinary microbiota. Herein, we sought to rule out confounding factors and clarify how urinary Eubacterium sp. CAG:581 promoted non-muscle-invasive bladder cancer (NMIBC) development. Methods: Differentially abundant urinary microbiota of 51 NMIBC patients and 47 healthy controls as the Cohort 1 were firstly determined by metagenomics analysis. Then we modeled the coculture of NMIBC organoids with candidate urinary Eubacterium sp. CAG:581 in anaerobic condition and explored differentially expressed genes of NMIBC organoids by RNA-Seq. Furthermore, we dissected the mechanisms involved into Eubacterium sp. CAG:581-induced extracellular matrix protein 1 (ECM1) and matrix metalloproteinase 9 (MMP9) upregulation. Finally, we used multivariate Cox modeling to investigate the clinical relevance of urinary Eubacterium sp. CAG:581 16S ribosomal RNA (16SrRNA) levels with the prognosis of 406 NMIBC patients as the Cohort 2. Results: Eubacterium sp. CAG:581infection accelerated the proliferation of NMIBC organoids (P < 0.01); ECM1 and MMP9 were the most upregulated gene induced by increased colony forming units (CFU) gradient of Eubacterium sp. CAG:581 infection, via phosphorylating ERK1/2 in NMIBC organoids of the Cohort 1. Excluding the favorable impact of potential contributing factors, ROC curve of the Cohort 2 manifested its 3-year AUC value as 0.79 and the cut-off point of Eubacterium sp. CAG:581 16SrRNA as 10.3 (delta CT value). Conclusion: Our evidence suggests that urinary Eubacterium sp. CAG:581 promoted NMIBC progression through ECM1/MMP9 pathway, which may serve as the promising noninvasive diagnostic biomarker for NMIBC.