One Gene May Be Key to Myeloma

June 24 -- MONDAY, June 23 (HealthDay News) -- Cancerous myeloma cells are so "addicted" to a gene known as IRF4, they simply can't live without it, new research has revealed.

Reducing the activity of the gene by only 50 percent is enough to kill myeloma cells without compromising other healthy activities, said scientists reporting in the current issue of Nature.

"This pathway is so critical to the growth of myeloma that, potentially, if you turn it off, you've found a chink in the armor," said Dr. Bart Kamen, executive vice president and chief medical officer at The Leukemia & Lymphoma Society.

The gene could present a target for future drug development.

"IRF4 is absolutely a target in myeloma. This is not an easy target but not an impossible target," said Dr. Louis Staudt, senior author of the paper and chief of the Lymphoid Malignancies Section, Metabolism Branch, Center for Cancer Research at the U.S. National Cancer Institute.

"It's obviously a little bit away, but we have the ability to fairly quickly figure out how to block [genes]," added Dr. Mitchell Smith, head of the lymphoma service at Fox Chase Cancer Center in Philadelphia.

Multiple myeloma, a cancer of the white blood cells, primarily affects older adults and, partly for that reason, often doesn't have a good prognosis.

What's more, there are least seven different "flavors" of multiple myeloma, each having its own unique genetic abnormalities, Staudt said. "One worries that would mean we'd need different drugs for each of these."

While there has been an explosion in new drugs to treat the disease over the past five to 10 years, there is still no cure, Smith said.

The authors took advantage of a genetic screen devised several years ago. This "Achilles' heel screen" uses RNA interference to spot particularly vulnerable parts of cancer cells

"It allows you to inactivate one gene at a time in a cancer cell and then ask what happens," Staudt explained. "We looked simultaneously at thousands of different genes . . . and then asked which one prevents the proliferation and survival of cancer cells."