Scientists use fruit fly to screen for lethal brain cancers

Knoxville Times (IANS) Friday 13th February, 2009

Researchers have turned the fruit fly into a lab model for an innovative study of gliomas, the commonest of malignant brain tumours, since the insect shares most of the genes with humans.

'Gliomas are a devastating disease but we still know very little about the underlying disease process,' explained John B. Thomas, professor in the molecular neurobiology lab of the Salk Institute for Biological Studies and senior co-author of the study.

'We can now use the power of Drosophila genetics to uncover genes that drive these tumours and identify novel therapeutic targets, which will speed up the development of effective drugs.'

Better models for research into human gliomas are urgently needed. Last year alone, about 21,000 people in US were diagnosed with brain and nervous system cancers, Senator Edward M. Kennedy the most famous among them.

About 77 percent of malignant brain tumours are gliomas and their prognosis is usually bleak. While they rarely spread to elsewhere in the body, cancerous glial cells quickly infiltrate the brain and grow rapidly, which renders them largely incurable even with current therapies.

Gliomas originate in brain cells known as 'glia' and are categorised into subtypes based on how aggressive they appear, with glioblastoma being the most common and most aggressive form of glioma.

Like most cancers, gliomas arise from changes in a person's DNA that accumulate over a lifetime. Most, if not all human glioblastomas carry mutations that activate the EGFR-Ras and PI-3K signalling pathways. Such mutations are also thought to play a key role in developing drug resistance.

Salk researchers are now using their fly model to search for genes and drugs that might block EGFR/PI-3K-associated brain tumours, said a Salk Institute release.

The drug tests are being done with co-authors Webster Cavenee, porfessor and associate professor Frank Furnari, both experts in brain tumour biology at the Ludwig Institute for Cancer Research at the University of California, San Diego.

These findings were published in the current edition of the Public Library of Science Genetics.