Inhibitory effect and mechanism of Lactobacillus crispatus on cervical precancerous cells Ect1/E6E7 and screening of early warning factors

OBJECTIVE: To study the potential mechanism of Lactobacillus crispatus inhibiting cervical squamous intraepithelial lesion (SIL) and screen the early warning factors of SIL. METHODS: The effects of Lactobacillus crispatus on the proliferation, apoptosis, cross pore migration and invasion and cytokines of cervical precancerous cells Ect1/E6E7 were detected respectively. The effect of Lactobacillus crispatus on the expression of differential proteins screened in Ect1/E6E7 cells were detected by Western blot. RESULTS: Lactobacillus crispatus significantly inhibited the proliferation, induced apoptosis and inhibited cell migration of Ect1/E6E7 cells in a time-dependent manner (P < 0.05), but had no significant effect on cell invasion. Lactobacillus crispatus significantly promoted the secretion of Th1 cytokines and inhibited the secretion of Th2 cytokines by Ect1/E6E7 cells (P < 0.05). In addition, compared with SiHa cells in the control group, the expression of differential proteins PCNA, ATM, LIG1 and HMGB1 in Ect1/E6E7cells decreased significantly, while the expression of TDG and OGG1 proteins increased significantly (P < 0.05). ABCG2 protein in Ect1/E6E7 cells was slightly higher than that in SiHa cells, but the difference was not statistically significant. What is interesting is that Lactobacillus crispatus significantly inhibited the expression of ABCG2, PCNA, ATM, LIG1, OGG1 and HMGB1 proteins in Ect1/E6E7 cells, and promoted the expression of TDG protein. CONCLUSIONS: Lactobacillus crispatus may inhibit the function of Ect1/E6E7 cells through multiple pathways and exert the potential to reverse the progression of SIL.