Update on Stem Cells: Potential for a Cure?

Cancer scientists are slowly but surely making potentially promising discoveries in stem cell research.

Stem Cells 101

Stem cells are immature body cells. They make identical copies of themselves and mature into different tissue types to replace aging or damaged cells.

Cancer stem cells are at the heart of tumors. Although they are just one to three percent of all cells in tumors, they have the greatest capacity to invade and spread. Cancer stem cells may also be resistant to chemotherapy and radiation, which is why, researchers suspect, cancer often returns after treatment.

Some cancer patients receive life-saving blood stem cell transplants to replace cells destroyed during treatment.

Cancer Stem Cell Research

Many scientists believe we must eradicate cancer stem cells if we hope to successfully cure cancer.

At the Cancer Centers of America, researchers are studying "mini stem cell transplants" for patients with certain types of leukemia, lymphoma, and other cancers. Physicians give patients lower, less toxic doses of treatment to eliminate some, but not all, of the bone marrow. They also suppress patients' immune systems to prevent them from rejecting the transplants. Using donated bone marrow cells, oncologists then try to destroy the cancer cells that were not eliminated by anticancer drugs.

At the University of Michigan, researchers created the first human embryonic stem cells lines carrying genes responsible for inherited diseases, allowing them to study the onset and progress of genetic diseases such as cancer.

They've also made several important direct cancer discoveries. For example, they've learned that prostate cancer cells target and overrun a section of bone marrow that makes red and white blood cells. It appears the cells stay dormant, and then become active years later. Researchers also learned how breast cancer stem cells work, so they may be able to attack breast cancer by blocking the signals that tell the cancer to multiply.

Elsewhere, scientists have identified proteins that influence how cancer stem cells can become any cell type in the body. They've also found new ways to measure circulating tumor cells in the body using genetic markers to identify cancer and cancer stem cells. Measuring circulating cells, rather than the whole tumors, may be more important for assessing the impact of chemotherapy and reducing the need for biopsies.

All of these findings open the door to develop potential new, targeted treatments, or help physicians determine which patients are highest risk for recurrence and poor prognosis.

National Cancer Institute. "Understanding Cancer Series: Blood Stem Cell Transplants." Web. 1 September 2006.

National Cancer Institute. "The Evolving Science of Cancer Stem Cells." Web.

Chustecka, Zosia. "Cancer Stem Cell Theory Boosted by Clinical Data." Medscape Medical News. Web. 29 December 2010.

Kim, Daniel, MD, Kwok, Brian, MD, Steinberg, Amir, MD. "Simultaneous Acute Myeloid Leukemia and Multiple Myeloma Successfully Treated with Allogeneic Stem Cell Transplantation." Southern Medical Journal 103(12) (2010): 1246-1249. Medscape Medical News. Web. 5 January 2011.

Chustecka, Zosia. "New Assay for Circulating Tumor Stem Cells May Be Game Changer." Medscape Medical News. Web. 5 April 2011.

Cancer Centers of America. "Mini Transplant Process." Web. 26 October 2010.

University of Michigan. "Prostate cancer spreads to bones by overtaking the home of blood stem cells." Press release. Web. 23 March 2011.

University of Michigan. "U-M researchers find indirect path to attack breast cancer stem cells." Press release. Web. 17 January 2011.

Physorg.com. "Tet further revealed: Studies track protein relevant to stem cells, cancer." Web. 30 March 2011.