A common biological molecule helps kill some cancer cells by blocking their guardian protein, according to City of Hope molecular biologists. The finding sheds light on the longstanding mystery behind the biomolecule’s anticancer activity.
Glucosamine is a common mono-saccharide, or simple sugar, found in cells. It also is a popular nutritional supplement, most often touted as a treatment for osteoarthritis.
|Viktor Chesnokov helped find how glucosamine kills cancer cells. (Photo by Darrin S. Joy)|
Researchers have long known that glucosamine can be toxic to some cancer cells while remaining harmless to normal cells.
Now, a team led by Keiichi Itakura, Ph.D., professor of molecular biology, has found that glucosamine can block the activity of a protein called signal transducer and activator of transcription 3, or STAT3.
STAT3 is highly overproduced in many cancer cells. Previous research has shown that STAT3, when activated, promotes cancer development and guards tumor cells from the immune system.
In the current lab study, Itakura and his team gave doses of glucosamine to prostate cancer cells that continuously produce STAT3. They then observed the effect on the cells and measured the amount of activated STAT3 produced by the cells. The team found that adding glucosamine greatly reduced the amount of activated STAT3, and the cells stopped growing and died.
“By blocking activation of STAT3, we prevent it from protecting the cancer cells,” said Itakura.
The team also found that the amounts of other proteins that help tumor cells grow, including one known as survivin, were lowered in cells exposed to glucosamine.
“Survivin is controlled by STAT3, so it makes sense that we see less of it when STAT3 is suppressed,” explained Viktor Chesnokov, Ph.D., assistant research scientist in the Department of Molecular Biology and lead author on the study.
The researchers suggested that, while more research is needed, glucosamine might be used to treat tumors that produce STAT3 continuously.
Chao Sun, Ph.D., research fellow in molecular biology, also contributed to the study, which appeared in the Sept. 10 issue of Cancer Cell International.