Biological mechanism behind diabetes and breast cancer association

American research shows a possible biological mechanism that explains the association between diabetes and breast cancer. The research was recently published in Nature Cell Biology.

Previous research has uncovered associations between diabetes and breast cancer. In addition, insulin resistance has been associated with breast cancer incidence and poorer survival.

The research shows a possible biological mechanism linking the two diseases. The authors show that extracellular vesicles (EVs), derived from breast cancer cells, suppress pancreatic insulin secretion and thus impair glucose homeostasis. EV-encapsulated miR-122 targets PKM in cells suppressing glycolysis and ATP-dependent insulin exocytosis. Mice that received high miR-122 EVs or had breast cancer tumors showed suppressed insulin secretion, increased endogenous glucose production, impaired glucose tolerance and fasting hyperglycemia.

These effects contribute to tumor growth and could be abolished by inhibition of EV secretion or miR-122. Compared to controls without cancer, breast cancer patients were found to have higher levels of circulating EV-encapsulated miR-122 and fasting glucose concentrations but lower fasting insulin. Impairment of glycemic control thus contributes not only to tumor progression, but also to the incidence of type 2 diabetes in breast cancer patients.

Bron:

Cao M, et al. Cancer-cell-secreted extracellular vesicles suppress insulin secretion through miR-122 to impair systemic glucose homeostasis and contribute to tumour growth. Nat Cell Biol. 2022;24:954-67.

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