How Cannabis Cuts Tumour Growth in Three Weeks
According to Harvard the active ingredient in cannabis cuts tumour growth in common lung cancer in half and significantly reduces the ability of the cancer to spread, which have been tested in both lab and mouse studies by Harvard.
The compound, Delta-tetrahydrocannabinol (THC), inhibits EGF-induced growth and migration in epidermal growth factor receptor (EGFR) expressing non-small cell lung cancer cell lines. Lung cancers that over-express EGFR are usually highly aggressive and resistant to chemotherapy, this was the first set of experiments done by Harvard.
Endocannabinoids, which are cannabinoids that are naturally produced in the body and activate these receptors. THC also targets the cannabinoids receptors CB1 and CB2 which are similar to endocannabinoids. The researchers suggest that THC or other designer agents that activate these receptors might be used in a targeted fashion to treat lung cancer.
Although a medical derivative of THC, known as Marinol, has been approved for use as an appetite stimulant for cancer patients, and a small number of U.S. states allow use of medical marijuana to treat the same side effect. Cannabinoids receptors CB1 and CB2 act through endocannabinoids (as well as THC) and are thought to play a role in variety of biological functions, including pain and anxiety control and inflammation.
In a recent study researcher first demonstrated that two different lung cancer cell lines as well as patient lung tumour samples express CB1 and CB2, and that non-toxic doses of THC inhibited growth and spread in the cell lines. Then, for three weeks, researchers injected standard doses of THC into mice that had been implanted with human lung cancer cells and found that tumours were reduced in size and weight by about 50 percent in treated animals compared to a control group. Also, a 60 percent reduction in cancer lesions on the lungs were found in the mice as well as a significant reduction in protein markers associated with cancer progression.
Harvard also speculate that THC may also interfere with angiogenesis and vascularization, which promotes cancer growth, and they also say that cancer could be activating molecules that arrest the cell cycle however they are not exactly sure as to why cancer inhibits tumour growth and tests are needed to be carried out to know exactly why.