“How obesity promotes colorectal cancerâ€
- January 24, 2016, 9:34 pm
- Breaking News
- 93 Views
HQ City Desk
QUETTA: People with obesity have a 50% greater risk of developing colorectal cancer than lean people according to a recent research.
The scientists have revealed a biological connection between obesity and colorectal cancer and they have identified an approved drug that might prevent the cancer from developing.
They found that obesity whether from excess fat carbohydrate consumption or both is associated with loss of the hormone guanylin. Guanylin is produced in the lining cells or epithelium of the intestine.
The lining of the intestines is very dynamic and continuously being replaced. A receptor guanylin cyclase C (GUCY2C) contributes to this regeneration. Guanylin is the hormone that turns on this receptor.
The findings showed that a high caloric diet turned off the expression of guanylin in the intestine leading to deactivation of a tumor suppressor pathway.
One feature of colorectal cancer is the deactivation of the guanylin gene. This has been seen in both humans and animals. Morbidly obese patients have an 80% lower guanylin gene expression compared with lean people.
It appears that the guanylin hormone receptor acts as a growth controlling tumor suppressor. Without the hormone the receptor is silenced from the early stages of the cancer. This causes the epithelium to become dysfunctional and sets up the conditions for cancer development.
The experiments showed that the hormone and its receptor were far more likely to be silenced in obese mice than in lean mice.
The team proposes that colorectal cancer could be prevented in obese individuals through hormone replacement therapy in the same way that diabetes is treated with insulin.
The researchers also showed that caloric restriction can reverse the effect of excess calorie consumption and reconstitute guanylin expression even in obese mice suggesting a role for lifestyle changes.
