NEW YORK (Reuters Health) - US researchers have identified a group of tyrosine phosphatase genes that appear to be tumor suppressor genes, according to a new study. Protein tyrosine phosphatase (PTP) mutations were most strongly associated with colorectal cancer. Twenty-six percent of colorectal tumors analyzed harbored such mutations.
PTPs and kinases are known to regulate tyrosine phosphorylation, which plays an important role in tumorigenesis, according to a paper in the May 21st issue of Science. While various kinase genes have been directly linked to tumorigenesis, relatively few phosphatase genes have been tied to malignancy.
Dr. Victor E. Velculescu, from Johns Hopkins University in Baltimore, and colleagues performed a mutational analysis of the PTP superfamily in various human cancer specimens. The authors identified a total of 83 somatic mutations in six PTPs.
In addition to being found in colorectal cancers, PTP mutations were also found in substantial proportion of lung, gastric, and breast cancers. By contrast, no mutations were found in pancreatic cancers, ovarian cancers, medulloblastomas, or glioblastomas, the researchers point out.
Analysis of the PTP mutations revealed several that would have resulted in absent or decreased phosphatase activity. Moreover, introducing a wild-type PTP, but not a mutant PTP, into cancer cells blocked tumor growth-further supporting the role of these genes as tumor suppressors.
“Like the analysis of genetic alterations in tyrosine kinases, the present study suggests the possibility of individualized therapy based on the mutate phosphatases present in specific tumors,” the investigators note.
Source: Science 2004;304:1164-1166. [ Google search on this article ]
MeSH Headings:Neoplasms: Genes, p53: DiseasesCopyright © 2002 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Reuters and the Reuters sphere logo are registered trademarks and trademarks of the Reuters group of companies around the world.
