A herpes virus suspected of causing Kaposi’s sarcoma, a cancer often found in AIDS patients, also may set off a reaction leading to multiple myeloma, a bone marrow cancer that kills 10,000 Americans annually, researchers say.
In a study to be published today in the journal Science, a group of California scientists reported finding the Kaposi’s sarcoma-associated herpes virus, or KSHV, in some types of blood cells of patients with multiple myeloma - but not in patients who are free of the disease.
Dr. James R. Berenson of the Veterans Affairs West Los Angeles Medical Center said the virus is not found in the malignant bone marrow cells themselves but in nearby dentritic cells. He said the virus apparently causes the dentritic cells to secrete interleukin-6, a protein that nurtures the myeloma tumors.
“The soil, the dentritic cell, is putting out a bunch of fertilizer, and that makes the seed, the tumor cell, germinate,” said Berenson.
Yuan Chang, a KSHV expert at Columbia University, said in Science that the study suggests a “novel mechanism” for causing cancer and that it could be an important discovery if it can be confirmed by other laboratories.
KSHV, a member of the highly troublesome family of herpes viruses, is thought to cause Kaposi’s sarcoma, a cancer that causes large purplish welts on the skin and then often spreads to internal organs. The disease once was rare but now is common among AIDS patients whose immune systems are unable to fight off the virus.
Berenson said that his team was investigating interleukin-6, which is a growth factor for myeloma cancer, when it discovered the presence of KSHV in the dentritic cells.