The role of Tannerella forsythia and Porphyromonas gingivalis in pathogenesis of esophageal cancer

Tannerella forsythia and Porphyromonas gingivalis are anaerobic, Gram-negative bacterial species which have been implicated in periodontal diseases as a part of red complex of periodontal pathogens. Esophageal cancer is the eight most common cause of cancer deaths worldwide. Higher rates of esophageal cancer cases may be attributed to lifestyle factors such as: diet, obesity, alcohol and tobacco use. Moreover, the presence of oral P. gingivalis and T. forsythia has been found to be associated with an increased risk of esophageal cancer. Our review describes the role of P. gingivalis and T. forsythia in signaling pathways responsible for cancer development. It has been shown that T. forsythia may induce pro-inflammatory cytokines such as IL-1β and IL-6 by CD4 + T helper cells and TNF-α. Moreover, gingipain K produced by P. gingivalis, affects hosts immune system by degradation of immunoglobulins and complement system (C3 and C5 components). Discussed bacteria are responsible for overexpression of MMP-2, MMP-2 and GLUT transporters.