Antibiotics fight stomach cancer.

The repeat may upset the regulation of HRASI, either by altering the DNA'S structure slightly or by allowing generegulating proteins to bind to this section of genetic material, suggests James F Gusella from Harvard University 

Krontiris suspects that other variably repeating regions influence the development of other diseases with genetic components, including diabetes.

New evidence reinforces the link between the ulcer-causing bacterium Helicobacter pylori and stomach cancer (SN: 12/14/91, p.399). Pilot studies in Europe suggest that treating people with antibiotics to get rid of these bacteria can also quash some early forms of this cancer.

It seems that when the bacteria infect the stomach lining, they cause an immune response that can lead to cancerous growth, says Peter G. Isaacson from the University College, London, Medical School in England. He and his colleagues treated six infected patients who had developed lymphoid tumors in their stomach linings. The antibiotics eliminated the bacteria in all six, and the cancer disappeared in five, they report in the Sept. 4 LANCET.

In a commentary accompanying the Isaacson report, Manfred Stolte from the Institute of Pathology in Bayreuth, Germany, says he also saw tumors regress in 12 of 32 similar cases, results that agree with other, unpublished work in Austria.

Isaacson and his colleagues also exposed tumor cells grown in the laboratory some of which came from infected stomach linings, to different strains of dead H. pylori. They then monitored the changes in immune-system messengers and in cellular activity

The bacteria seem to exert their cancer-causing influence by stimulating the immune system's T-cells, which then produce chemical messengers that cause different lymphoid cells, B-cells, to increase in number, Isaacson says. But the bacteria had no effect on B-cell tumors taken f rom other parts of the body or on more aggressive stomach tumors, the group reports.

The eradication of both tumor and infection suggests that H. pylori stimulates tumor growth and that antibiotics should be tried as an inexpensive first line of attack in these early stomach cancers, the researchers conclude.