Breast stem cells could be targeted through Notch
The growth of a rare population of breast stem cells appears to be regulated by Notch signaling, UK scientists have reported.
Presenting the research at the Breast Cancer Campaign's first scientific meeting in London, Robert Clarke, from the University of Manchester, said that Notch signaling could offer a novel target for breast cancer treatment.
Breast epithelial stem cells are thought to be the primary target in the etiology of breast cancer, but current therapies might leave them intact. Consequently, if treatments could be developed that target these highly potent cells, patients may experience a reduction in tumor recurrence, the meeting delegates were told.
As most breast cancers express estrogen receptor (ER) ?, the researchers examined how the biology of cells expressing ER? is related to that of stem cells from normal human breast epithelium.
Clarke and team discovered that ER?-positive cells co-expressed two putative stem cell markers – p21CIP1 and Msi-1. In addition, a population of putative breast stem cells was enriched for ER?-positive cells six fold.
The data suggest a model where scattered ER?-positive cells are stem cells that self-renew through asymmetric cell division and generate patches of differentiated cells.
Further research showed that the breast cancer cell lines and primary tumors contain a self-renewing population that is highly regulated by the Notch receptor-signaling pathway.
Clarke told MedWire News: "Our findings so far suggest that they [stem cells] may be regulated by the Notch receptor signaling pathway and this pathway may represent a new drug target for breast cancer treatment in the future.
"We continue to test this possibility in the lab and are hopeful that it will be useful in the clinic, perhaps in combination with current therapies which target the tumor bulk."
Breast cancer research: the past and the future; London, UK: 1 November 2006
http://www.breastcancercampaign.org/...ic_conference/
Linear Mode
