The research was presented here today at the 95th Annual Meeting of the American Association for Cancer Research. Inhibition of experimental colon cancer metastasis by the GABA-receptor agonist Nembutal: Abstract No. 5513
A drug that acts as a "downer" on the central nervous system also works to suppress metastasis in an experimental model of colon cancer, according to researchers from M.D. Anderson Cancer Center in Houston, Tex.
The barbiturate Nembutal, or pentobarbital, is known to have similar effects in the brain as gamma-aminobutyric acid (GABA), a neurotransmitter-inhibiting amino acid. Nembutal acts in the manner of a GABA receptor agonist. GABA acts through cell surface receptors, and GABA receptor membrane proteins are present not only in the brain, but on colon and ovarian cancer cells as well.
Premal Thaker, M.D., and colleagues, tested whether Nembutal activated GABA receptors on the cancer cells both in culture and in vivo using a mouse model for colon cancer. After confirming the presence of GABA receptors in the colon cancer cell lines, the researchers documented a marked reduction in cellular cAMP concentrations in colon cancer cell lines treated with Nembutal.
In animal models, nude mice were injected in the cecum or spleen with KM12SM, a GABA receptor positive colon cancer cell line. Nearly half as many mice treated with Nembutal (4 of 10) developed primary tumors after injection in the spleen as the non-Nembutal treated mice (8 of 10). When the cells were injected into the
Contact: Aimee Frank
American Association for Cancer Research