Molecular biologists at the University of California, San Diego, have discovered the mechanism causing breast cancer in women with type 2 diabetes. The journal Nature Cell Biology indicates that the pancreas, when affected by type 2 diabetes, does not secrete sufficient amounts of insulin, which regulates the sugar needed by cells. This leads to elevated blood glucose levels, in turn causing disturbances in blood flow, neural function, and immune system operation. Researchers note that the development of breast cancer in women with type 2 diabetes is 20-27% higher compared to other diseases. The progression of diabetes essentially increases two years after cancer diagnosis, with a 20% rise after ten years. According to World Health Organization data, doctors diagnose 2.3 million women with breast cancer annually, leading to the deaths of 685,000 of them.
From the analysis of molecules secreted by cancer cells, researchers found that they produce a significant amount of the miR-22 RNA molecule. This nucleotide sequence typically does not exist outside liver tissues and cells, where the RNA molecule regulates fat metabolism and also plays a significant role in the development of hepatitis C and a form of cancer. The researchers, through studying the effect of miR-122 in mouse organs injected with RNA molecules or cancer cells, discovered that large accumulations of miR-122 infiltrated pancreatic cells and suppressed the production of insulin molecules. Thus, cancer cells obtain the necessary calories for rapid growth and reproduction while depriving neighboring healthy cells of nutrition.
The researchers believe that cancer cells could be suppressed by returning the body’s sugar levels to normal. Insulin implants and diabetes medications slow tumor growth and improve the condition of the mice. The researchers hope that, thanks to these findings, it will be possible to treat breast cancer with drugs that inhibit the action of miR-122.
