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

Oral squamous cell carcinoma (OSCC), main head and neck squamous cell carcinomas (HNSCCs), remains a global health concern with unknown pathogenesis. Veillonella parvula NCTC11810 was observed to decrease in saliva microbiome of OSCC patients in this study and the aim was to detect the novel role of Veillonella parvula NCTC11810 in regulating the biological characteristics of OSCC through TROP2/PI3K/Akt pathway. Oral microbial community changes of OSCC patients were detected by 16S rDNA gene sequencing technology. CCK8 assay, Transwell assay, and Annexin V-FITC/PI staining were used for proliferation, invasion, and apoptosis analysis of OSCC cell lines. Expression of proteins were determined by Western blotting analysis. Veillonella parvula NCTC11810 showed decreased in saliva microbiome of TROP2 high-expressed OSCC patients. Culture supernatant of Veillonella parvula NCTC11810 promoted the apoptosis and inhibited the proliferation and invasion ability of HN6 cells, while sodium propionate (SP), the main metabolite of Veillonella parvula NCTC11810, played a similar role through the inhibition of TROP2/PI3K/Akt pathway. Studies above supported the proliferation-inhibiting, invasion-inhibiting, and apoptosis-promoting function of Veillonella parvula NCTC11810 in OSCC cells which provided new insights into oral microbiota and their metabolite as a therapeutic method for OSCC patients with TROP2 high expressing.