Scientists at Johns Hopkins Oncology Center in Baltimore haveidentified a gene that may suppress colon cancer.
The gene, called MCC (mutated in colon cancer), appears to beone of the first genes damaged in the multistep process bywhich a normal cell becomes a cancer, said Dr. Kenneth W.Kinzler, who directed the study, which was published today inScience.
Kinzler, a member of Dr. Bert Vogelstein's team at the center,told BioWorld that MCC may be linked to an inherited form ofcolon cancer that maps to the same region of chromosome 5 asdoes MCC. These characteristics make MCC potentially usefulfor identifying individuals predisposed to colon cancer beforethe disease occurs, he said.
Colon cancer, the second-leading cancer in the United States,kills 61,000 Americans each year. About 155,000 new caseswere diagnosed in 1990, said Kinzler.
Kinzler cautioned that the researchers still must show thatdefects in MCC cause colon cancer. And the study must beconfirmed and extended before MCC becomes a candidatediagnostic or therapeutic, he said.
Dr. Fred Reynolds, director of technical services at OncogeneScience Inc., said that once MCC is verified as a tumorsuppressor gene, it will take a large effort to develop aconvenient test based on it. Other companies developing tumorsuppressor-based products include Applied bioTechnology Inc.,F. Hoffmann-La Roche & Co., Oncor Inc. and Viagene Inc.
Kinzler's team identified MCC point mutations and deletions inthree colon cancer cell lines.
He said scientists believe that cancer occurs when four to sixgenes are damaged. Vogelstein's group proposes that MCC, theras oncogene, and tumor suppressor genes DCC and p53 are keyplayers in colon cancer development. Vogelstein's labdiscovered DCC and showed that p53 is a tumor suppressorgene.
-- Carol Talkington Verser, Ph.D. Special to BioWorld
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