Effect of <i> Porphyromonas gingivalis </i> up-regulating Src protein expression on proliferation, migration and invasion of esophageal squamous cell carcinoma

<b>Objective</b> To investigate the effect ofPorphyromonas gingivalis ( P. gingivalis , Pg) on the proliferation and migration of esophageal squamous cell (KYSE30) through up-regulating proto-oncogene tyrosine protein kinase (Src). <b>Methods</b> KYSE30 cells were divided into four groups: no infection group (Pg- group, without Pg bacterial solution), inhibitor group (without Pg bacterial solution, with Src inhibitor PP2 5 nM for 24 h), infection group (Pg+ group, with only 50 μL of Pg bacterial solution to infect cells) and infection + inhibitor group (Pg+ inhibitor group, PP2 5 nM for 24 h, then 50 μL of Pg solution for infection). Twenty-four hours after infection in the Pg- group and Pg+ group, the expressions of Src and Pg were detected by immunofluorescence. The expressions of Src and STAT3 proteins in the Pg+ group and Pg+ inhibitor group were detected by Western blot at 0, 12, 24 and 48 h, respectively. Twenty-four hours after Pg infection, the migration and invasion number, proliferative activity and apoptosis rate of cells in the four groups were detected by Transwell assay, CCK-8 method and flow cytometry, respectively. <b>Results</b> Compared with Pg- group, the fluorescence intensity of Src and Pg in Pg+ group significantly increased ( P ＜0.05). The expression levels of Src and STAT3 protein in Pg+ group increased at 12, 24 and 48 h of Pg infection compared with at 0 h ( P ＜0.05). The expression levels of Src and STAT3 protein in Pg+ inhibitor group at 12 and 24 h of Pg infection were higher than those at 0 h ( P ＜0.05). At the same time point after infection, the expression levels of Src and STAT3 protein in Pg+ inhibitor group were lower than those in Pg+ group ( P ＜0.05). Compared with Pg- group, the number of migrating and invading cells in inhibitor group decreased, cell proliferation activity decreased, and cell apoptosis rate increased ( P ＜0.05). Compared with Pg- group, the number of migratory and invasive cells in Pg+ group increased, cell proliferation activity increased, and cell apoptosis rate decreased ( P ＜0.05). Compared with Pg+ group, the number of migration and invasion cells in Pg+ inhibitor group decreased, cell proliferation activity decreased, and cell apoptosis rate increased ( P ＜0.05). <b>Conclusion</b> Pg infection can promote the expression of Src and STAT3 in esophageal squamous cell carcinoma cells,and inhibiting Src can reverse the promotion of Pg on the migration and invasion of esophageal squamous cell carcinoma cells, thereby reducing cell proliferation activity and induce cell apoptosis.