Cancer support cells may promote growth.

• Position: Tumors

Cancers may cause surrounding supportive cells to evolve and ultimately promote cancer growth, say scientists at the University of North Carolina, Chapel Hill. Their research offers what is believed to be the first evidence that mutations within cancer cells can signal surrounding tissues to alter their molecular composition in ways that promote tumor growth and proliferation. Moreover, their findings suggest that cell mutations that promote cancer progression may arise in cells other than the predominant cancer cell.

While not offering immediate application to the treatment of human cancers, the research indicates that new anti-tumor therapies may be more effective if their targets are broadened to include molecules within supporting cells of the cancer. These additional target cells are in the tumor's surrounding "microenvironment," or stroma, including the supporting connective tissue that forms the framework of organs such as the breast, colon, and prostate. They also are found in the tumor's blood vessels, or its vasculature.

"Basically, virtually all the studies on genetic changes or changes in gene expression have focused on the cancer cell, on events within the cancer cell itself," points out Terry Van Dyke, professor of genetics, biochemistry, and biophysics. Thus, research focused solely on the predominant cancer cell, such as epithelial cells that form the bulk of many tumors, including breast cancer, would be on the accumulated mutations that have allowed the cell to survive and grow unchecked.

"However...