A gene that plays a key role in an aggressive form of breast cancer could also function as a cancer "off switch."
Dr. Alex Swarbrick and Dr. Simon Junanka of the Sydney Garvan Institute of Medical Research in Australia say new research has revealed that the "inhibitor of differentiation 4" (ID4) gene could be used to control triple-negative breast cancer.
The study, published in Nature Communications, indicates that the ID4 gene is the determining factor in the transformation of a stem cell into a specialist cell. It may drive the occurrence of triple-negative breast cancers, which come from different cell types.
It's encouraging news for those whose lives have been affected by triple-negative breast cancer, which account for 15 percent of all breast cancers. Patients diagnosed with triple-negative breast cancer face an increased risk of recurrence and a shorter survival period than those with other types of breast cancer.
Of those diagnosed with triple-negative breast cancer, about half are killed by the disease within a three to five year period. Those that beat the cancer typically survive eight years after treatment.
The research team found ID4 is created in hefty amounts in about 50 percent of all triple-negative cancers.
"We also showed that if you block the ID4 gene in experimental models of triple-negative breast cancer, the tumor cells stop dividing," said project leader Swarbrick.
The study indicates triple-negative breast cancer is two separate diseases. The research focused on determining the differences between the two cancers and the role of stem cells, in both the development of breasts and in disease occurrence.
"We speculate, therefore, that by blocking ID4, it might be possible to turn stem-cell-like breast cancers into less aggressive breast cancers that may even respond to tamoxifen," Swarbrick said. Tamoxifen is a successful approach in blocking oestrogen receptor-positive breast cancers and growth.
"If we are correct, that would be remarkable," he added.
According to the study, stem cells share similar traits to cancer cells in that they both have a long life, are resistant to treatment and feature an unlimited capacity to divide.
"We don't know yet whether we are seeing a real oestrogen-dependent cancer after ID4 is blocked – one with an effective oestrogen receptor – or just a caricature of one," Swarbrick said. He added there are tools for investigating processes on a genome-wide basis which would allow a thorough mapping of ID4 interactions.
The next step for the research team is investigating the biochemistry of ID4 in a cell and how to block the cell.
