New Delhi, Aug 23: In a study that could help design better drugs for breast cancer, researchers at the Indian Institute of Science Education and Research (IISER)-Bhopal have identified the mechanism by which breast cancer cells proliferate and spread.  The team studied the regulation of a gene called ‘ESRP1’ in breast cancer. They found that there is a difference in the expression of the ESRP1 gene between normal and tumour tissues of breast cancer patients. The gene was expressed more in breast tumour tissues than normal tissues. They then explored the regulatory mechanism behind this. The expression of a gene goes through many steps, the first of which is transcription. The ‘message’ encoded in the DNA of the gene is transcribed into RNA signals by proteins called transcription factors. The team found that in tumour tissues, a transcription factor called E2F1 that regulates transcription of ESRP1 gets up-regulated, thereby increasing its expression and eventually leading to excessive growth of breast cancer cells. The team also found the mechanistic aspects of cancer spread to other parts of the body or what is technically called metastasis. Cancerous tumors create regions of reduced oxygen due to poor blood circulation. It has been known that such oxygen-deprived regions instigate metastasis. The IISER researchers have unraveled the mechanism behind this also. They have shown that the transcription factor E2F1 fails to bind the ESRP1 promoter in oxygen-deprived breast cancer cells, thereby downregulating the expression of ESRP1.  This downregulation may cause the cancerous cells to break free from primary cancer and join the bloodstream to be carried to other parts of the body, thereby resulting in metastasis. The study was led by Dr. Sanjeev Shukla, Associate Professor, and DBT/Wellcome Trust India Alliance Fellow in the Department of Biological Sciences at IISER-Bhopal. The work was supported by the DBT/Wellcome Trust India Alliance Fellowship Grant. Speaking to India Science Wire, Dr. Shukla said, “Our research, for the first time, shows the reason behind an elevated expression of a key gene, ESRP1, in breast tumor tissue supporting tumor progression. Another important part of the discovery was a novel epigenetic…