Endometrial Regenerative Cells Inhibit Cancer

Cell Cycle, February 15, 2009

Researchers have announced a new and somewhat surprising discovery with the novel population of extremely promising adult stem cells known as endometrial regenerative cells (ERCs). Already recognized for their highly angiogenic properties, ERCs are currently in development as a treatment for critical limb ischemia, which is an advanced form of peripheral artery disease. Now, in a counter-intuitive turn of events, ERCs have also demonstrated a strong ability to inhibit angiogenesis in tumor growth.

ERCs share certain similarities with mesenchymal stem cells while also exhibiting unique surface markers, and the cells are highly superior in a number of characteristics such as growth factor production, differentiability and expandability. In this latest study, researchers examined the ability of unmanipulated ERCs to influence gliomal growth in a Sprague Dawley rat model. A glioma is a type of cancer that arises from glial cells and is therefore most commonly found in the brain though also less often in the spine.

In a paper entitled, "Inhabition of Intracranial Glioma Growth by Endometrial Regenerative Cells", the scientists found that ERCs inhibit the growth of these types of tumors. In fact, regardless of the route of administration, the ERCs were observed to induce dramatic inhibition of the glioma, with a 49% reduction in volume after intravenous administration of the ERCs and a 46% reduction in volume following intratumoral administration. In both cases, both an inhibition of angiogenesis as well as a reduction in the number of CD133+ cells were associated with the diminished intracranial tumor growth.

Such findings suggest a number of intriguing possibilities, such as, for example, an association between the strong anti-inflammatory properties of ERCs and the conceptual model of cancer in which tumor stem cells are thought to be triggered to enter the cell cycle as a result of cellular injury, which usually precipitates an inflammatory response. Although the precise molecular mechanisms underlying the behavior of ERCs have yet to be fully elucidated, they nevertheless offer a number of new and promising therapeutic modalities.

As the authors explain in their paper, "Despite the angiogenic potential of ERCs in the hindlimb ischemia model, these data support a paradoxical tumor inhibitory activity of ERCs. Further studies are needed to determine the qualitative differences between physiological angiogenesis, which seems to be supported by ERCs, and tumor angiogenesis which appeared to be inhibited."