A surprising new study has researchers rethinking the origins of
gastric tumors. Stomach cancer is a major cause of cancer
deaths, especially in developing countries. About 15 years ago,
researchers linked stomach cancer to infection with the ulcer-
causing bacterium Helicobacter pylori. H. pylori infections
apparently foster stomach cancer because of the persistent
inflammation they produce. Most researchers thought that
inflammatory cells probably spurred epithelial cells in the
stomach lining to become cancerous. But in the 26 November issue
of Science, researchers offer a more radical possibility--that
the cells that ultimately give rise to cancer are not the
epithelial cells but bone marrow stem cells that are recruited
to try to repair the stomach lining. To study the role of bone-
marrow-derived cells in stomach cancer, a team led by JeanMarie
Houghton of the University of Massachusetts Medical School in
Worcester and Timothy Wang, who is now at Columbia College of
Physicians and Surgeons in New York Cit