BALTIMORE, May 21 (UPI) -- U.S. scientists said Friday they have discovered genetic mutations linked to more than a quarter of colon cancers.
Scientists at Johns Hopkins University and the Howard Hughes Medical Institute said the mutations also are linked to several other common cancers, including breast and lung.
They analyzed 157 colon cancers and found 77 mutations in six genes that make tyrosine phosphatases, enzymes that help coordinate signals that manage cell growth, death, differentiation, and nearby tissue invasion. The enzymes normally work by turning off tumor growth, as so-called tumor suppressors, but in cancers the genes are mutated and no longer work properly.
Because it is difficult to restore a mutated suppressor gene with cancer drugs, the investigators think phosphatases
themselves are not good drug targets. Yet, for every tyrosine phosphatase there is a matching enzyme, called a tyrosine kinase, which plays an opposite role -- turning a pathway on and accelerating cellular events. So these enzymes might become good targets for drug therapies, they said.
