Guest blogger Alan Trounson — March stem cell research highlights

Each month CIRM President Alan Trounson gives his perspective on recently published papers he thinks will be valuable in moving the field of stem cell research forward. This month’s report, along with an archive of past reports, is available on the CIRM website.

The lead article in this month’s report focuses on CIRM-funded work in Irv Weissmann’s lab at Stanford. It reports on a protein on the surface of cancer cells that in essence says “don’t eat me” to the immune system cells that are supposed to seek out, engulf and destroy tumor cells. This cell surface protein is called CD47. More important, an antibody that blocks CD47 seems pretty effective in reactivating the immune system’s attack on the tumors—at least in mice. My colleague Amy Adams blogged about this research here.

There are two quite different aspects of this research that excite me. First, it is a finding that could be very important clinically that clearly derived from basic research. Irv’s team originally found the cell surface protein when they were trying to understand the fundamental relationship between the immune system and cancer cells. It turns out CD47 is expressed on the leukemia cells they were studying, but highly expressed on leukemia stem cells, which are hypothesized to be responsible for the tendency of leukemia to relapse after treatment.

The other reason to be excited about this work is that it goes counter to much of the direction of cancer research today. Many of the exciting new therapies are coming from an increased understanding of how individual most cancers are from one another. The newest therapies tend to be most effective for a narrow set of tumors, often with specific genetic compositions. This latest work showed the single antibody to be able to shrink and sometimes eliminate many different solid tumors. The Stanford team reported results for cancer cells from seven different human tumors transplanted into mice. Such a broad-spectrum cancer treatment, even if it has to be paired with other agents, has the potential to be less costly because of the market size.

My full report is available online, along with links to my reports from previous months.

A.T.