Fig. 2
From: Oral microbiota and Helicobacter pylori in gastric carcinogenesis: what do we know and where next?
Oral bacteria increase the production of various types of inflammatory mediators such as interleukin-1β (IL-1β), IL-6, IL-17, IL-23, TNF-α, and MMP-8 and MMP-9, which are involved in DNA damage, tumor invasiveness, migration, metastasis and prevention of cell apoptosiss. High content of IL-1β correlates with tumor invasiveness and migration. IL-6 contributes to apoptosis suppression. IL-6 also influences the metastasis and invasion processes via increasing the expression of MMPs. TNF-α may induce DNA damage through generation of ROS. TNF-α can affect invasion and motility processes via inducing expression of MMPs. TNF-α: tumor necrosis factor-α, MMPs: matrix metalloproteinases, ROS: reactive oxygen species