Cancer Gene Therapies Improving

July 2007 -

Effective gene therapies for cancer are becoming more plausible for the near future as illustrated by this report from EurekAlert!:

"A molecularly engineered therapy selectively embeds a gene in pancreatic cancer that shrinks or eradicates tumors, inhibits metastasis, and prolongs survival with virtually no toxicity. The researchers call the system a versatile expression vector - nicknamed VISA. It includes a targeting agent, also called a promoter, two components that boost gene expression in the target tissue, and a payload - in this case a gene known to kill cancer cells.

It's all packaged in a fatty ball called a liposome and delivered intravenously. In a test of the therapy against two aggressive lines of pancreatic cancer in two different types of mice, researchers loaded the VISA system with a mutant version of a gene named Bik, which expresses a protein that naturally forces cancer cells to kill themselves. The team created the more lethal mutant and named it BikDD. Untreated control mice in both experiments all died within 40 days. Mice treated with the mutant gene delivered via a less-targeted viral promoter driven expression system employing cytomegalovirus (CMV) all died within 90 days, most much earlier.

In both trials, the VISA-BikDD mice lived longer, with at least half surviving for 14 months with no detectable sign of cancer recurrence."