suspects hybrids. gastric tumor cells that have both a marker of bone marrow derived cells and gastric epithelial cell marker (yellow tag) are raising questions about the origins of stomach cancer.
a surprising new study includes researchers to rethink the origins of gastric tumors.
Stomach cancer is a major cause of cancer death, especially in developing countries. There are approximately 15 years, cancer researchers related stomach infection with the bacteria causing ulcer Helicobacter pylori. H. pylori infections apparently foster stomach cancer due to persistent inflammation they produce. Most researchers thought that inflammatory cells probably stimulated epithelial cells of the stomach lining to become cancerous. But in November 26th issue of Science , researchers offer a more radical possibility - that the cells which finally give rise to cancer are not epithelial cells, but stem cells in the bone marrow which are recruited to try to repair the lining of the stomach.
To investigate the role of bone marrow derived cells in the gastric cancer, a team led by Jean-Marie Houghton of the University of Massachusetts Medical School in Worcester and Timothy Wang, now at Columbia College of physicians and Surgeons in New York, and colleagues used a mouse strain that, when infected with H. felis , developing gastric changes similar to those observed in humans infected H. pylor i. Before infecting mice, however, researchers have irradiated to destroy bone marrow; they were then given the cell transplants rodent marrow carrying a genetically modified marker which allows cells to be distinguished from specific animal cells.
After about 20 weeks of infection, bone marrow cells labeled began incorporating in the lining of the stomach. There, they began to differentiate. But the resulting cells are not quite normal. Their shapes were deformed and showed improved growth abnormalities similar to those cells undergoing cancerous transformation in the beginning. Finally, they produce cancerous tumors.
supportThe results still the idea that the persistent inflammation promotes cancer development. Perhaps most interesting, the results of Houghton and Wang accredit the new controversial concept that cancer can arise from stem cells ( Science , September 5, 03, p. 1308), although some experts cells stem say they are not convinced that the cells of the bone marrow behave as proposed by UMass, Worcester, team. They note that researchers are not definitively rule out the possibility that the cells of the bone marrow fused with epithelial cells of the stomach.
However, the paper is likely to attract considerable research interest. "What it has done is open a new field in gastric carcinogenesis," says Helicobacter expert Richard Peek of Vanderbilt University School of Medicine in Nashville, Tennessee. "He is really a concept totally new, "said Emad El-Omar, a Helicobacter researcher at the University of Aberdeen, UK" It will prepare people to think very hard "on the origins of stomach cancer, he said.
Related Sites
Houghton and colleagues science paper
Read more on H. pylori US Centers for disease control and prevention
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