Page 114 - D. Cancer biology

[D. Cancer biology-72]

Oral microbiota-epithelium crosstalk regulates local and

distal carcinogenesis

NA-YOUNG SONG¹

¹Dept. of Oral Biology, Yonsei University College of Dentistry, Seoul 03722, Korea

Bacteria and fungi, two major components of the microbiota, develop both antagonistic and symbiotic relationships
on the host epithelium. However, the crosstalk between epithelium and microbiota on tumorigenesis is poorly
understood. Oral mucosa is a well-known habitat for various microorganisms and cancer patients frequently present

oral fungal infection. Thus, we investigated whether oral fungal infection can regulate local and distal tumorigenesis,

particularly in the context of interaction between oral microbiota and epithelium. IKKα is one of the crucial factors
regulating the homeostasis of squamous epithelial tissues. To investigate the crosstalk between epithelium and
microbiota, we adopted IKKα conditional knockout mice in epithelial cells of oral mucosa and skin. Then, the mice

were orally inoculated with Cladosporium cladosporioidesfungi. Disruption of epithelial homeostasis by IKKα
ablation promoted bacterial colonization in oral cavity and skin, oral dysplasia, and skin carcinogenesis in mice.

Interestingly, it was further accelerated by oral fungal-bacterial symbiosis. Thus, disrupted epithelial homeostasis by
IKKα loss allows the bacterial-fungal symbiosis in the oral mucosa, which expedites local and distal tumorigenesis.