Marijuana cuts lung cancer tumor growth in half, according to Harvard researchers:
In the present study, the researchers first demonstrated that two different lung cancer cell lines as well as patient lung tumor samples express [cannabinoid receptors] CB1 and CB2, and that non-toxic doses of THC[the active ingredient in marijuana] inhibited growth and spread in the cell lines. “When the cells are pretreated with THC, they have less EGFR stimulated invasion as measured by various in-vitro assays,” Preet said.Then, for three weeks, researchers injected standard doses of THC into mice that had been implanted with human lung cancer cells, and found that tumors were reduced in size and weight by about 50 percent in treated animals compared to a control group. There was also about a 60 percent reduction in cancer lesions on the lungs in these mice as well as a significant reduction in protein markers associated with cancer progression, Preet says.
Although the researchers do not know why THC inhibits tumor growth, they say the substance could be activating molecules that arrest the cell cycle. They speculate that THC may also interfere with angiogenesis and vascularization, which promotes cancer growth.