A low protein diet is effective in inhibiting the growth of colorectal cancer

[메디컬투데이=한지혁 기자] Reducing protein intake has been shown to be effective in inhibiting the growth of colorectal cancer.

A study on the effect of a low protein diet on the growth of colorectal cancer was published in the journal Gastroenterology.

Colorectal cancer refers to a situation in which cells in the colon or rectum grow abnormally. According to statistics in the United States, colorectal cancer accounts for 7.9% of all cancer incidence and 8.6% of cancer-related deaths in 2022.

According to previous studies, hyperactivation of a molecule called “mTORC1” is associated with more than 70% of human cancers, including colorectal cancer, and inhibition of mTORC1 can lead to inhibition of tumor growth.

Although the effect of drugs that inhibit the mTORC1 signaling pathway has been clinically proven, they have immunosuppressive side effects and have limitations as the recurrence rate is high after treatment is finished.

In this study, the researchers demonstrated that amino acids absorbed into the body through protein intake activate mTORC1, and limiting it reduces mTORC1, helping to inhibit tumor growth.

First, the research team analyzed colorectal cancer cells in a mouse model and found that mTORC1 activity was higher when amino acids were supplied.

Next, they fed a live mouse model of colorectal cancer a low-protein diet for two weeks, followed by chemotherapy for one month. The control mice’s regular diet contained 21% protein, while the low protein diet contained only 4% protein.

As a result of their observations, the researchers found that early tumor growth was slower and more cancer cells died in mice fed a low-protein diet.

Through further analysis in the laboratory, the researchers confirmed that a low-protein diet, specifically a decrease in the amino acids “leucine” and “cystine”, alters the mTORC1-associated signaling pathway via the “GATOR1” and “GATOR2” protein complex. “. . .

In an amino acid-rich environment, GATOR2 enhances the activity of mTORC1. On the other hand, mTORC1 is inactivated by GATOR1 in an amino acid-poor environment.

Through examination of human colorectal cancer tissue, the researchers confirmed that the higher the expression of mTORC1, the higher the resistance to chemotherapy and the worse the prognosis.

They noted that a genetic test that detects amino acids could predict in advance the effect of a low-protein diet on each patient’s gene expression pattern.

According to experts, molecules such as GATOR and mTORC1 are responsible for sensing and signaling nutrients that cancer cells consume for growth, and a lack of nutrients that are not synthesized in the body, such as amino acids, can lead to massive cancer cell death. . .

The researchers argued that to apply the findings of this study to humans, various variables such as the tumor microenvironment should be taken into account and that follow-up clinical studies will be needed for this.

Medical Today reporter Han Ji-hyeok ([email protected])

[저작권자ⓒ 메디컬투데이. 무단전재-재배포 금지]