by Simone Alves

Regulation is controlled by PTEN, PI3K/Akt and drug-effluxing ABCG2

Some chemotherapeutics used to target gliomas may actually increase the cancer stem cell population and make tumours more aggressive.

Working in mice genetically engineered to have gliomas, Eric Holland and his team at the Memorial Sloan-Kettering Cancer Center in New York showed that a previously identified population of brain cells known as the side population is more tumorigenic than other cells in the brain. The proportion of cells belonging to the side population (SP) was also several-fold larger in glioma-susceptible mice compared to normal mice, and this population increased in the absence of the tumour suppressor gene PTEN. SP cells from gliomas were able to generate neurospheres in vitro, suggesting that this population can harbour brain cancer stem cells.

vivan g. cheungHoward Hughes Medical Institute researchers have identified a group of genes that influence a person’s sensitivity to radiation. The findings are a step toward a long-term goal of developing new tests that would help physicians determine the optimal dosage of radiation for cancer treatment based on a person’s genetic profile.

“This study identifies a set of genetic variants that influence how a cell responds to radiation-induced damage,” said Vivian G. Cheung, senior author of a report published on April 6, 2009, in the journal Nature.

stem cell therapiesby Amber Dance

A biotech start-up sees stem cells as targets, not transplants

When Captain Kirk and the crew of the starship Enterprise travel back in time to the 1980s in Star Trek IV: The Voyage Home, Dr. McCoy runs across an elderly woman with kidney failure languishing in the hospital. He offers her a pill to swallow. Minutes later, the cured patient rejoices before her baffled physicians: "The doctor gave me a pill and I grew a new kidney!"

To physician Leonard Zon of Harvard Medical School in Boston, the scene parallels his goals for the company he helped found, Fate Therapeutics. Fate, located in La Jolla, California, launched in 2007 with a US$12 million budget. Fate aims to develop small molecules and biologics that stimulate a patient's own stem cells, marrying the tried-and-true methodology of drug development to the relatively new science of stem cells.

douglas sippby Sorapop Kiatpongsam and Douglas Sipp

Costs, risks, benefits, and a call for regulation

For some patients with debilitating illnesses, hope seems only a plane ride away. Though the scientific mainstream has dismissed stem cell clinics operating outside standard medical practice, patients continue to go. Patients and providers accuse the biomedical establishment of inaction and excessive caution; the biomedical establishment accuses providers of selling false hope to patients who have exhausted all available options. The resulting impasse arguably stands as the greatest current threat to the advancement of stem cell therapies, and the strongest evidence of the need for regulatory frameworks capable of addressing the needs of the diverse stakeholders in the 'offshore' stem cell drama.

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This news service is provided by Good Samaritan Institute, located in Santa Rosa Beach, Florida.

GSI is a non-profit dedicated to the advancement of medical research by improving communication among scientists.