(Cannabinoids and Cancer Cells) "Cannabinoids, the active components of marijuana and their other natural and synthetic analogues have been reported as useful adjuvants to conventional chemotherapeutic regimens for preventing nausea, vomiting, pain, and for stimulating appetite. Before the discovery of specific cannabinoid systems and receptors, it was speculated that cannabinoids produced their effects via nonspecific interaction with cell membranes. Cannabinoids are proving to be unique based on their targeted action on cancer cells and their ability to spare normal cells. Variation in the effects of cannabinoids in different cell lines and tumor model could be due to the differential expression of CB1 and CB2 receptors. Thus, overexpression of cannabinoid receptors may be effective in killing tumors, whereas low or no expression of these receptors could lead to cell proliferation and metastasis because of the suppression of the antitumor immune response."

Source

Sarfaraz, Sami; Adhami, Vaqar M.; Syed, Deeba N.; Afaq, Farrukh; and Mukhtar, Hasan, "Cannabinoids for Cancer Treatment: Progress and Promise," Cancer Research (Philadelphia, PA: American Association for Cancer Research, January 2008) Vol. 68, pp. 341-342.
http://cancerres.aacrjournals…