Immune changes linked to diabetes could guide development of new cancer treatments

New research published in The Journal of Immunology reveals a link between high blood sugar levels and type 1 diabetes (T1D) that may provide clues for developing new cancer treatments. The study found that hyperglycemia, which is common in T1D patients, is associated with a decreased risk of certain cancers such as melanoma, breast, and colon cancer. Researchers hypothesize that this link could be due to changes in immune cells, specifically T cells, caused by high blood sugar levels.

To investigate further, scientists observed that tumors in mice with hyperglycemia grew more slowly compared to diabetic mice receiving insulin or mice with normal blood sugar levels. When they examined the cause, they discovered that hyperglycemia reprogrammed T cells to better control tumor growth. Hyperglycemic mice had a higher number of T cells, and these T cells were more effective at fighting tumors.

This enhanced cancer-fighting ability could be attributed to hyperglycemia leading to a higher concentration of inflammatory immune cells, which contribute to their ability to combat cancer.

However, when T1D mice were given insulin to regulate their blood sugar, the heightened cancer-fighting abilities of their T cells were lost. To further understand the specific changes in T cells from hyperglycemic mice, researchers compared T cells from hyperglycemic mice, diabetic mice receiving insulin, and those with normal blood sugar levels.

They found that T cells from hyperglycemic mice had an increased use of a particular cellular signaling pathway, which contributed to the T cells' increased cancer-fighting ability.

By identifying this signaling pathway as a factor that enhances T cell tumor-fighting abilities, researchers believe it could lead to the development of new cancer treatments that mimic this enhancement. The researchers also discovered that similar changes in immune cells were present in people with hyperglycemia. According to Dr. Anamika Bose, the study's senior author, "Our findings open several research avenues for new cancer immunotherapies by applying the changes we see in T cells of patients with type 1 diabetes and mimicking those cell changes in new treatments for all patients."