Researchers at Stanford University School of Medicine have discovered, for the first time, a common molecular pathway that is used by both normal stem cells and cancer stem cells when they reproduce themselves.See also: Common Trigger In Cancer And Normal Stem Cell Reproduction Found, ScienceDaily, August 7, 2009. About the article:
Downregulation of miRNA-200c Links Breast Cancer Stem Cells with Normal Stem Cells by Yohei Shimono and 14 co-authors, including Michael F Clarke, Cell 2009(Aug 7); 138(3): 592-603. [FriendFeed entry][PubMed Citation]. Summary:
Human breast tumors contain a breast cancer stem cell (BCSC) population with properties reminiscent of normal stem cells. We found 37 microRNAs that were differentially expressed between human BCSCs and nontumorigenic cancer cells. Three clusters, miR-200c-141, miR-200b-200a-429, and miR-183-96-182 were downregulated in human BCSCs, normal human and murine mammary stem/progenitor cells, and embryonal carcinoma cells. Expression of BMI1, a known regulator of stem cell self-renewal, was modulated by miR-200c. miR-200c inhibited the clonal expansion of breast cancer cells and suppressed the growth of embryonal carcinoma cells invitro. Most importantly, miR-200c strongly suppressed the ability of normal mammary stem cells to form mammary ducts and tumor formation driven by human BCSCs invivo. The coordinated downregulation of three microRNA clusters and the similar functional regulation of clonal expansion by miR-200c provide a molecular link that connects BCSCs with normal stem cells.For a commentary, see the latter part of: Breast cancer stem cells resemble healthy stem cells, resist chemotherapy by Monya Baker, The Niche, August 10, 2009.