PTEN Gene Suggests Treatment for Melanoma

Researchers have discovered that a switched-off PTEN gene allows malignant melanoma to grow and spread, suggesting that the introduction of normal PTEN into cells might represent a new therapeutic approach for the disease. The findings were reported in the June 1, 2003, issue of Cancer Research.

In noncancerous cells, PTEN normally starts a chain reaction ensuring that malfunctioning and damaged cells are killed. In contrast, abnormal cancerous cells gain the ability to switch off PTEN, allowing the dysfunctional cells to survive and thrive. Accumulation of multiple changes like this in melanoma cells results in the development of a faster growing and more aggressive tumor. The researchers believe PTEN may be responsible for 30-60% of melanomas. They used chromosome transfer technology to transfer an entire chromosome 10 from healthy cells into the abnormal melanoma cells. This introduction of chromosome 10, which contains the PTEN gene, temporarily switched-off the tumor cell growth in mice and allowed cell death to resume. Eventually, however, the melanoma cells begin to grow again. Introducing the PTEN gene into melanoma cells using a harmless virus could be a new therapeutic approach for killing melanoma cells.

"These discoveries may lead to another crucial weapon in the rather small arsenal of treatments available for this dangerous disease and offer the first hope for a new melanoma treatment target in decades,” said Gavin Robertson, Ph.D., assistant professor of pharmacology, pathology, and dermatology at Penn State College of Medicine, Hershey Medical Center (Hershey, PA, USA).