Relationship between colitic cancer and the intestinal microbiome

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K18102
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 55020:Digestive surgery-related
• Research Institution: Keio University
• Principal Investigator: Ishida Takashi 慶應義塾大学, 医学部(信濃町), 助教 (90573395)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 潰瘍性大腸炎 / 腸内細菌 / 発癌 / 肥満

Outline of Final Research Achievements

The role of the intestinal microbiome in colitic cancer and obesity-related colorectal cancer and is unclear. This study aimed to clarify the relationship between the intestinal microbiome and tumorigenesis using a mouse model.
We compared an obese and insulin-resistant type 2 diabetes mouse model [KKAy] to wild-type mice (WT) [C57BL/6 J]. Azoxymethane was intraperitoneally injected to develop a mouse model CRC. At 26 weeks, we compared the number of tumors and the intestinal microbiome. We also compared them across two models, namely, antibiotic cocktail and co-housing. In all models, KKAy mice had a significantly greater number of tumors than WT mice. Analysis showed that the distribution of the intestinal microbiome changed in both models; however, no difference in tumor development was observed.
Based on the results, the intestinal microbiome may not be associated with tumorigenesis in obesity-related CRC. It may be necessary to think of other facts linked to obesity-related CRC.

Free Research Field

消化器外科学

Academic Significance and Societal Importance of the Research Achievements

大腸癌発癌に、特定の腸内細菌や代謝産物が関与していることが明らかとなれば、腸内細菌叢を変化させることにより、発癌予防につながることが期待される。
本研究では、腸内細菌叢と腫瘍発現の直接的な関連を示すことはできなかったが、さらに別のモデルマウス（小腸・大腸の多発腫瘍モデルマウスであるAPC min/+マウスなど）を用い、腸内細菌及び代謝産物の解析を進めることを検討している。