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more in the mystery of breast cancer stem cells
...but are mice and humans the same--they ought to be able to do this with human stem cells,too. Will keep the radar out!
Study Says Mouse Breast Stem Cells Are Similar to Aggressive Human Breast Cancer [Journal of the National Cancer Institute; Subscribe; Sample]
A study by Geoffrey Lindeman, M.D., Ph.D., Jane Visvader, Ph.D., and colleagues at the Walter and Eliza Hall Institute in Melbourne, Australia, in collaboration with the BC Cancer Agency in Vancouver, Canada, finds that mouse mammary stem cells express receptor patterns similar to those of aggressive (or basal) human breast cancer, in which the stem cells did not express estrogen and progesterone receptors but did express another receptor. In contrast, mouse mammary cells that were not stem cells (luminal cells), expressed estrogen and progesterone receptors, similar to less aggressive types of breast cancer.
In an accompanying editorial, William F. Anderson, M.D., and Rayna Matsuno of the National Cancer Institute in Bethesda, Md., discuss the importance of Lindeman's findings. They write, "These data provide opportunity for reflection and change. At a minimum, breast cancer can no longer be viewed as a single biologic entity. [...] If breast cancer consists of a mixture of at least two main types, we need a stratified rather than a unified approach for breast cancer research, prevention, and treatment."
ABSTRACT: Steroid Hormone Receptor Status of Mouse Mammary Stem Cells [Journal of the National Cancer Institute; Subscribe; Sample]
The estrogen receptor ? (ER?), progesterone receptor (PR), and erbB2 (Her2 in humans) are important prognostic markers of human breast cancer, and they are variably expressed in different subtypes of breast cancer. The basal subtype, for example, is negative for ER?, PR, and Her2 by immunohistochemistry. We investigated the expression of these signaling molecules in enriched populations of mouse mammary stem cells and luminal cells that were isolated according to their differential expression of CD24 and the ?6?1-integrin complex. We found that the basal population, which is enriched in mouse mammary stem cells, did not express ER?, PR, or ErbB2/Her2 but did express epidermal growth factor receptor (EGFR)/ErbB1, whereas the subset of cells enriched for luminal cells expressed ER? (37% of cells) and PR (40% of cells) but not ErbB2/Her2 or EGFR/ErbB1. Ovariectomy confirmed the importance of estrogen signaling to luminal cell proliferation but had no effect on the size of the mouse mammary stem cell-enriched population. Thus, mouse mammary stem cells were negative for ER?, PR, and ErbB2 and appeared to share common properties with poor-prognosis basal breast cancer.
Interestingly they had EGFR1 as did a woman I was helping with basal (triple negative) breast cancer. Look to see Iressa, Tarceva, and Erbitux used more in trials...
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