KOLKATA: A team of researchers from Saha Institute of Nuclear Physics (SINP) and Indian Institute of Chemical Biology (IICB) from Kolkata in collaboration with MD Anderson Cancer Centre, Texas, have identified a protein, which may hold key to treat the deadliest form of breast cancer , dubbed “triple-Negative” breast cancer, which is still non-responsive to therapy.The initial findings have already been published in the research journal, Nature Communications. The researchers are now trying to design small molecules — which will mimic this protein — that can initiate the self-killing of tumour cells.This Indo-US collaborative research, initiated nearly five years back, brought together senior cancer researchers Chandrima Das, a chromatin biologist at SINP, IICB’s structural biologist Siddhartha Roy and Houston-based genomic medicine expert Kunal Rai, attempting to modulate the genetic behaviour of cancer cells to combat the disease.“The loss of factors responsible for maintaining the normal state of the cell can transform a healthy cell into tumorigenic state. The idea is to restore these factors in cancer cells to initiate the self-killing of the oncogenic cells, ultimately leading to the regression of the tumour,” Das said.The three senior scientists along with their team of researchers Santanu Adhikary, Deepavali Chakravarti, Christopher Terranova, Isha Sengupta, Anirban Dasgupta, Dushyant Kumar Srivastava and a group of statistians and clinicians from SINP, IICB and MD Anderson Cancer Centre has found out that loss of a protein, named UBR7, alters the epigenome of the normal breast cells, rendering them tumorigenic.In fact, this protein is absent in “triple-negative” breast cancer, that has an enhanced state of metastasis but no known treatment. They isolated this protein from an intensive search of factors that are present in normal cells but absent in breast cancer cells.“Studies in mouse models showed that injecting them with the protein stopped cancer cells from proliferating,” said Adhikary. A clinical analysis of cancer patients and their kin clearly showed that UBR7 expression was lesser as the breast tumour became more advanced. The initial findings published say loss of UBR7 may be among the key reasons, which cause this aggressive subtype of breast cancer. Now the research is attempting to test these findings in clinical settings.“Breast cancer is one of the major causes of mortality in females,” explained a researcher. It is the “heterogeneity” of the disease is a therapeutic challenge. Through early diagnosis breast cancer can be treated with conventional therapies, which include chemotherapy , radiation therapy, hormonal therapy and surgery. Complexities, however, arises with a subtype of the disease, which is “triple-negative” breast cancer. This subtype is the most aggressive and therapy non-responsive form of the disease, with chances of relapse.“Although accumulation of genetic defects lead to the development of breast cancer, epigenetic abnormalities are also known to play significant role,” explains Das.