Madrid, Spain: Compounds in cannabis inhibit cancer cell growth in human breast cancer cell lines and in pancreatic tumor cell lines, according to a pair of preclinical trials published in the July issue of the journal of the American Association for Cancer Research.

In one trial, investigators at Complutense University in Spain and the Institut National de la Sante et de la Recherche Medicale (INSERM) in France assessed the anti-cancer activity of cannabinoids in pancreatic cancer cell lines and in animals. Cannabinoid administration selectively increased apoptosis (programmed cell death) in pancreatic tumor cells while ignoring healthy cells, researchers found. In addition, "cannabinoid treatment inhibited the spreading of pancreatic tumor cells ... and reduced the growth of tumor cells" in animals.

"These findings may contribute to ... a new therapeutic approach for the treatment of pancreatic cancer," authors concluded.

In the second trial, investigators at Spain's Complutense University reported that THC administration "reduces human breast cancer cell proliferation [in vitro] by blocking the progression of the cell cycle and by inducing apoptosis." Authors concluded that their findings "may set the bases for a cannabinoid therapy for the management of breast cancer."

Previous preclinical data published in May in the Journal of Pharmacological and Experimental Therapeutics reported that non-psychoactive cannabinoids, particularly cannabidiol (CBD), dramatically halt the spread of breast cancer cells and recommended their use in cancer therapy.

Separate trials have also shown cannabinoids to reduce the size and halt the spread of glioma (brain tumor) cells in animals and humans in a dose dependent manner. Additional preclinical studies have demonstrated cannabinoids to inhibit cancer cell growth and selectively trigger malignant cell death in skin cancer cells, leukemic cells, lung cancer cells, and prostate carcinoma cells, among other cancerous cell lines.

Full text of both studies, "Cannabinoids induce apoptosis of pancreatic tumor cells via endoplasmic reticulum stress-related genes" and "Delta-9-tetrahydrocannabinol inhibits cell cycle progression in human breast cancer cells through Cdc2 regulation" are available in the July 1, 2006 issue of Cancer Research, available online at: http://cancerres.aacrjournals.org/. Additional information on cannabinoids' anti-cancer properties is available in NORML's report, "Cannabinoids as Cancer Hope," online at: http://www.norml.org/index.cfm?Group_ID=6814