Lactobacilli inhibit cervical cancer cell migration in vitro and reduce tumor burden in vivo through upregulation of E-cadherin.

The present study was designed to investigate the antitumor effects of Lactobacillus and the potential mechanisms. Cell Counting Kit-8 (CCK-8) assays were carried out to determine suitable doses for investigating the inhibitory effect of lactobacilli on cell migration ability of HeLa and U14 cells in vitro. In addition, western blot assays were performed to investigate the possible mechanisms corresponding to its antitumor effects. Furthermore, a xenograft mouse model was established for investigating the E-cadherin expression in tumor tissues after treatment with lactobacilli. Our results showed that live lactobacilli [multiplicity of infection (MOI) of 1,000:1] significantly possessed inhibitory effects on cell migration ability of cervical cancer cells. Lactobacilli (MOI: 1,000:1) significantly upregulated E-cadherin expressions in HeLa and U14 cells (p<0.05). On the contrary, our results showed that inactivated lactobacilli could not affect the E-cadherin expression levels in HeLa and U14 cells. Similar to the western blot assay, immunohistochemistry results also indicated that lactobacilli treatment significantly upregulated E-cadherin in tumor tissues (p<0.05). In conclusion, our results above suggest that lactobacilli have the potential for inhibiting the migratory ability of cervical cancer cell lines, and the possible pharmacological mechanism may be closely related to the upregulation of E-cadherin.