Obesity Impairs Immune Cell Function in Cancer, Triggers Tug-of-War for Fuel
December 10, 2020
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Research by a Harvard Medical School (HMS)-led research team has uncovered a new mechanism by which obesity can interfere with the immune system’s ability to fight cancer. Their studies demonstrated how, in tumor-bearing mice fed a high-fat diet, cancer cells reprogram their metabolism in response to the increased fat availability, so they can better consume energy-rich fat molecules, which then deprives tumor-killing T cells of fuel and accelerates tumor growth. The cancer cells effectively outcompete the immune cells in the battle for fuel, leading to reduced numbers and activity of CD8+ T cells in the tumor microenvironment (TME). Because CD8+ T cells are the main weapon used by immunotherapies that activate the immune system against cancer, the study results could point to potential new strategies for improving these treatment approaches.
Scientists studied the relation between obesity and cancer
A metabolic tug-of-war.
Tumor cells are marked in cyan and CD8+ T cells mark in red. On the top is a tumor from an animal on a normal diet. On the bottom is a tumor from an animal on a high-fat diet. There are significantly fewer CD8+ T cells in the obese tumor.
Credit: Ringel et al, 2020
Obesity is responsible for various diseases, including cancer, as well as worse prognosis and survival. In many studies, scientists have studied obesity-related processes that cause tumor growth, like metabolic changes and chronic inflammation, yet the interplay between obesity and cancer has remained elusive.