Science and Medicine : Suspect Gene Discovered

A team of U.S. and Italian researchers reported last week the discovery of a gene that appears to cause some cancers of the pituitary gland and may also trigger tumor growth in the thyroid, ovary and similar glands.

Reporting in the British journal Nature, the researchers said they identified mutations on the “gasp” gene that causes uncontrolled production within a cell of a growth-promoting molecule called cyclic AMP. UC San Francisco researcher Henry Bourne, who headed the study, said the mutations appear to alter a protein that regulates an enzyme that makes cyclic AMP. The defect causes the cyclic AMP-making protein to be permanently switched on, leading to the uncontrolled growth of tumor cells.

In addition to pituitary cells, researchers said other cells programmed to grow in response to elevated cyclic AMP are in the thyroid, ovary, testes, adrenal and other endocrine glands. Although non-endocrine cells are not as sensitive to cyclic AMP changes, Bourne said cyclic AMP-promoting gene mutations may play a secondary role in the growth of cancers outside the endocrine system. The identification of the gasp gene brings to about 50 the number of genes known to be cancer-causing when damaged or mutated.