Pregnancy reduces the risk of breast cancer through pre-genetic reprogramming

previous studies showed that women who became pregnant before the age of 25 were 30 percent less likely to develop breast cancer. Pregnancy can lead to a series of cellular and molecular changes in mammary epithal cells (MECs) in adult women.A new study of mice has revealed how pregnancy reduces the risk of breast cancer. The researchers found that pregnancy reprogrammed chromatin enhancers in mice's MECs and affected the transcriptional output of cancer-causing transcription factors (cMYC). The findings were published in the journal Nature Communications.The paper's author, Dr. Camila dos Santos, an assistant professor at cold spring harbor laboratories in the United States, studies how signals that appear during pregnancy alter gene expression, how these changes affect normal and malignant breast development, and the molecular details that provide pregnancy protection.Dr Camila dos Santos said: "Pregnancy itself changes the way DNA areas are opened or closed. Like yo-yo, the center is what we call a nuclear gadget. It is a bunch of proteins that protect DNA. When you release the ball, you get a string that represents that part of the DNA is open. And because it is open, transcription factors can bind and turn genes on or off. If you pull the yo-yo back, everything goes inside the yo-yo. This is what we call closed chromosomes, so transcription factors cannot be combined there. "The team overexacted the cMYC gene and found that MEC after pregnancy was resistant to the carcinogenic effects of the gene. In contrast, the MEC is not resistant to cMYC before pregnancy and is still prone to cancer. Basically, pregnancy prevents breast cells from interacting with cancer-causing genes, and doing so does not change the normal pregenitology of pregnancy.Dr. Dos Santos's research also showed that cMYC over-expression drives MEC into aging after pregnancy, preventing cell growth and preventing cancer from developing.According to Dr. Dos Santos, senescing cells are "in gray areas and do not grow or die," meaning they can age, die or become cancerous. The cancer gene is turned off, while the gene that causes the cell to die is turned on. These signals are a key factor in how these cells do not turn into cancer.Dr. Dos Santos and his team are now determining whether human breast cells work in the same way as mice. They also transplanted pregnancy-altering cells into mice that had never been pregnant, hoping to find out if the altered cells affected the non-pregnant environment.In summary, this study provides useful insights into the protective nature of pregnancy and may lead to new drug targets. (Biological exploration)