Washington: Researchers have identified a transcription factor, known as ZEB1, that is capable of converting non-aggressive basal-type cancer cells into highly malignant, tumor-forming cancer stem cells (CSCs).
Intriguingly, luminal breast cancer cells, which are associated with a much better clinical prognosis, carry this gene in a state in which it seems to be permanently shut down.
The researchers from Whitehead Institute report that the ZEB1 gene is held in a poised state in basal non-CSCs, such that it can readily respond to environmental cues that consequently drive those non-CSCs into the dangerous CSC state.
Basal-type breast carcinoma is a highly aggressive form of breast cancer.
According to a 2011 epidemiological study, the 5-year survival rate for patients with basal breast cancer is 76 percent, compared with a roughly 90 percent 5-year survival rate among patients with other forms of breast cancer.
"We may have found a root source, maybe the root source, of what ultimately determines the destiny of breast cancer cells-their future benign or aggressive clinical behavior," Whitehead Founding Member Robert Weinberg, who is also a professor of biology at MIT and Director of the MIT/Ludwig Center for Molecular Oncology, said.
Transcription factors are genes that control the expression of other genes, and therefore have a significant impact on cell activities.
In the case of ZEB1, it has an important role in the so-called epithelial-to-mesenchymal transition (EMT), during which epithelial cells acquire the traits of mesenchymal cells.
Unlike the tightly-packed epithelial cells that stick to one another, mesenchymal cells are loose and free to move around a tissue.
The findings are published in the journal Cell.
ANI
