drugs already approved indirectly attack breast cancer stem cells (responsible for bc

[Lani]

growth and spread).
I heard much about this at last year's AACR annual conference in Washington, DC in APril

Now it has been published(and via open access):


U-M researchers find indirect path to attack breast cancer stem cells
[University of Michigan Health System]
ANN ARBOR, Mich. — Scientists at the University of Michigan Comprehensive Cancer Center have identified a potential new way of attacking breast cancer stem cells, the small number of cells in a tumor that fuel its growth and spread. Researchers found that breast cancer stem cells are regulated by a type of cell derived from bone marrow, called mesenchymal stem cells. These cells are drawn from the bone marrow to the cancer and create a "niche" for the cancer stem cells, allowing them to replicate.

"The importance of this is that we may be able to attack breast cancer stem cells indirectly by blocking these signals from the niche," says study author Max S. Wicha, M.D., Distinguished Professor of Oncology and director of the University of Michigan Comprehensive Cancer Center.

Breast cancer stem cells were first identified by Wicha and colleagues at the University of Michigan in 2003. Cancer stem cells are believed to be resistant to current chemotherapies and radiation treatment, which researchers say may be the reason cancer so often returns after treatment.

Little is known about the cancer stem cell niche - a type of microenvironment that is highly associated with tumor growth and metastasis. The researchers looked at mesenchymal stem cells, which arise in bone marrow. They found that breast cancers in mice sent out signals which attracted mesenchymal stem cells from the bone marrow into the tumor where these cells interacted and stimulated the growth of breast cancer stem cells.

Researchers then identified two signals from a cytokine network - a type of protein that affects how cells communicate - that were responsible for stem cell regulation. These same cytokines play a role in inflammation and drugs that block them have already been approved for the treatment of inflammatory diseases such as rheumatoid arthritis. By blocking these cytokine signals, researchers hope that they can successfully target the cancer stem cell population providing a more effective treatment for breast cancer.

Results: of the study appear in the Jan. 15 issue of Cancer Research.

Additional authors: From U-M: Suling Liu, Sing J. Ou, Shawn Clouthier, Shivani H. Patel, Hasan Korkaya, Amber Heath, Julie Dutcher, Celina G. Kleer, Younghun Jung, Gabriela Dontu, Russell Taichman; from Centre de Recherche en Cancerologie de Marseille: Christophe Ginestier

Funding: National Institutes of Health, Taubman Research Institute

Disclosure: Wicha has financial holdings in OncoMed Pharmaceuticals, which has applied for a patent on cancer stem cell technologies.

OPEN ACCESS: Breast Cancer Stem Cells Are Regulated by Mesenchymal Stem Cells through Cytokine Networks
[Cancer Research]
We have used in vitro and mouse xenograft models to examine the interaction between breast cancer stem cells (CSC) and bone marrow-derived mesenchymal stem cells (MSC). We show that both of these cell populations are organized in a cellular hierarchy in which primitive aldehyde dehydrogenase expressing mesenchymal cells regulate breast CSCs through cytokine loops involving IL6 and CXCL7. In NOD/SCID mice, labeled MSCs introduced into the tibia traffic to sites of growing breast tumor xenografts where they accelerated tumor growth by increasing the breast CSC population. With immunochemistry, we identified MSC-CSC niches in these tumor xenografts as well as in frozen sections from primary human breast cancers. Bone marrow-derived MSCs may accelerate human breast tumor growth by generating cytokine networks that regulate the CSC population.