Singapore scientists uncover gene associated with aggressive breast cancer

SINGAPORE - Scientists here have uncovered a gene associated with triple negative breast cancer (TNBC), an often deadly disease.

The scientists from the Agency for Science, Technology and Research's (A*Star) Genome Institute of Singapore (GIS), together with local clinicians and colleagues in the United States, identified a biomarker, a gene called RASAL2, which is strongly associated with TNBC.

This newly identified gene provides a target for developing new therapeutics designed to treat the highly aggressive carcinoma that often relapses and spreads after chemotherapy. Unlike other types of breast cancers, TNBC tumours do not respond to targeted therapy.

Using breast cancer cell lines and genomic data from patient samples, molecular biologist Min Feng and her GIS colleagues found that TNBC patients whose tumours have high levels of RASAL2 tend to have a lower survival rate compared to those whose tumours have low levels of this gene.

The study also showed that "silencing" the RASAL2 gene can lead to reduced metastasis, or spreading of cancer cells, in mouse models.

The findings were published recently in the Journal of Clinical Investigation, a top medicine and research journal.

The study is a result of collaboration with consultants such as as Dr Dave Hoon at the John Wayne Cancer Institute in Santa Monica, California and Dr Tan Ern Yu at Tan Tock Seng Hospital.

Dr Tan, a breast cancer doctor, said: "Therapeutic options remain limited and women with TNBC have a higher risk of disease relapse, with prognosis being generally poor after a relapse."

The finding of RASAL2 points to the variety in genetic makeup of breast cancer tumours, she said, adding that it "explains why not everyone with tumours of the same disease stage responds the same way to similar treatment."

The study's project leader Professor Qiang Yu, who is the senior group leader of cancer therapeutics and stratified oncology programme at the GIS, said further work will need to be done to apply the laboratory findings to clinical practice.