Adiponectin suppresses tumorigenesis in Apc(Min)(/+) mice.

Recent reports have shown that adiponectin has a suppressive effect on various types of malignancy. In order to clarify the role of adiponectin in colorectal carcinogenesis, we examined the effect of exogenous administration of adiponectin on intestinal polyp formation in C57BL/6J-Apc(Min)(/+) mice, which possess a point mutation in the Apc gene. And we found that adiponectin treatment significantly decreased the number of adenomatous polyps, especially polyps larger than 2mm in diameter, in the small intestine. Two major receptors for adiponectin, AdipoR1 and AdipoR2, were expressed in adenomatous polyps, and their expression levels were not altered by adiponectin injection. In conclusion, adiponectin suppresses the growth of intestinal adenomas in the Apc(Min)(/+) mice. Increasing the adiponectin level may be a new strategy for the prevention of colorectal cancer at an early step of carcinogenesis.