Haywire. commandeering a signaling pathway , H. pylori causes cells to malform.
most pathogenic bacteria have been hunted for a long time, but for decades got a microbe with murder. Discovered in 1982, Helicobacter pylori triggers ulcers and cancer that kill 7 million people each year, scientists have learned much about the capabilities ulcer causing bug. Now a new study clarifies H. pylori deadliest talent, showing exactly how it forces the stomach cells to deform and migrate -. a first step in cancer transformation
People infected H. pylori are two to six times more likely than uninfected people to develop either the stomach or lymphoma cancer . When H. pylori infects the lining of the stomach, the stomach cells may lie until they resemble hummingbird beak. The microbe is known to inject a protein called CagA in stomach cells, where it is marked with phosphate groups. Because the addition or removal of phosphate from protein can interfere with cellular signals and help induce cancer, scientists have questioned whether it was H. pylori 's strategy.
Read, molecular oncologist Masanori Hatakeyama Hokkaido University in Sapporo, Japan, and colleagues first made an assumption that the human protein CagA interacts with cells of the stomach inside. They chose the hepatocyte growth factor (HGF), because the stomach cells treated with it exactly as CagA treated cells. HGF receptor alters a signaling protein called SHP-2, and the group wondered whether CagA done too.
Scientists have found that antibodies against CagA fish out SHP-2 from cell extracts of the stomach, and vice versa, indicating that the two proteins team up. Moreover, cells infected with a mutated version of CagA which does not bind SHP-2 helped CagA elongate cells. They proved the point by showing that SHP-2 clips additional signaling proteins phosphates, but only when it is related to CagA. Together, these results mean that CagA plugs into the normal cell signaling system, Hatakeyama said, leading the cell by mistake and put it at risk of becoming cancerous.
Cellular microbiologist Brett Finlay calls the work "a great step forward" in explaining how H. pylori tweaks normal cell signaling pathways, pushing the cells of the stomach a little more . malignancy other experts point out that most of the molecular links between H. pylori and cancer remain to be discovered - but H. pylori investigators are closing in on their careers
Related Sites
Facts H. pylori infection CDC
More background on H. pylori , sponsored by the pharmaceutical company AstraZenica
information H. pylori and ulcers of the National Institutes of Health
the benefits of H. pylori
0 Komentar