Immune response to cancer stem cells may dictate cancer's course

Although stem cells hold incredible promise in the fight against certain diseases, in cancer they are anything but helpful. In fact, mounting evidence is showing that a tumor's growth and spread may depend on "cancer stem cells," which comprise only a very small subset of the tumor. Now, a new study by Rockefeller University scientists shows that immunity to cancer stem cells may help protect people with a precancerous condition from developing the full-blown disease, and that these cells could be an important target for cancer vaccines.

About three percent of adults over 40 test positive for a condition known as monoclonal gammopathy of undetermined significance, or MGUS. MGUS itself is relatively benign, but in a small number of cases it progresses into multiple myeloma, a cancer of blood plasma cells. Yet despite the fact that MGUS and myeloma cells are genetically quite similar, researchers had been unable to figure out why most MGUS patients never develop the cancer. In research published in the March 26 issue of the Journal of Experimental Medicine, Madhav Dhodapkar, associate professor and head of Rockefeller's Laboratory of Tumor Immunology and Immunotherapy, shows that MGUS patients who naturally develop an immune response to an embryonic stem cell protein, called SOX2, appear to be protected against the development of myeloma.

Dhodapkar and his colleagues tracked patients with early plasma cell tumors