Tyrosine kinases power chemical reactions in cells, particularly those involved in cell division. Normally, these molecules are carefully regulated to keep a tight lid on cell growth. But they can lose that regulation when tyrosine kinase genes mutate. Instead of powering reactions only when appropriate, for example, the tel-pdgfrb protein runs constantly, like an engine that won't shut off.

"Mutations in tyrosine kinases can push cells to divide," says Grisolano. "If this is combined with a mutation that blocks cells from maturing, as does the aml1-eto gene, it can lead to cancer."

For example, mutations in a gene known as flt3 (pronounced flit 3), also in the tyrosine-kinase gene family, are among the most common mutations in people with AML. Drugs that block flt3 are being developed as a possible treatment for AML. Tel-pdgfrb is closely related to flt3.

"This study further supports the idea that tyrosine kinases may be highly worthwhile targets for new drugs to treat AML," says Tomasson.

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Contact: Darrell E. Ward
wardd@msnotes.wustl.edu
314-286-0122
Washington University School of Medicine
1-Aug-2003