Propionate-producing Veillonella parvula regulates the malignant properties of tumor cells of OSCC

Abstract Oral squamous cell carcinoma(OSCC) remains a global health concern with high mortality and morality around the world. Emerging evidence implicates the abnormal abundance and species of oral microbiota are associated with the development of OSCC. Veillonella parvula is an anaerobic Gram-negative coccus and the resident member of the normal oral microbial community. In our study, 16S rDNA (V4) amplicon sequencing of salivary microbiome genome revealed that OSCC patients with a high expression of trop2 showed a dysbacteriosis and characterized with a significant decreased distribution of veillonella parvula. In vitro study, Veillonella parvula treatment promoted the apoptosis inhibited the proliferation and invasion ability of TROP2-high expressed head and neck sauamous cell carcinema HN6 cells compared with the human oral keratinocyte (HOK) cells through its metabolite products rather than the bacteria cell itself. Further, Propionate the main metabolite of Veillonella parvula also plays the similar anti cancer role through inhibiting the activation of TROP2 related PI3K/Akt pathway. These results suggest that propionate, the SCFA metabolite of Veillonella parvula induces cell apoptosis, inhibits cell proliferation and invasion through reducing the activation of TROP2/PI3K/AKt pathway in OSCC cells.