Through the results of widespread experimentation of the… well… let’s say “non-scientific” variety, it’s pretty well known that marijuana has the side effect of making the user very hungry. This is one of the many physiological effects of the active ingredient THC (?9-tetrahydrocannabinol). More relevantly, however, THC and other cannabinoids are actively being investigated for various useful clinical purposes, including the treatment of cancer through the inhibition of tumor growth.
A new study by Salazar et al. in The Journal of Clinical Investigation demonstrates that THC causes tumor cells to begin to degrade themselves from the inside (a process called autophagy, i.e. “self-eating”). Although autophagy has been shown to promote cell survival in some cases and cell death in others, the authors show that in this case it causes cancer cells to undergo programmed cell death (apoptosis). Thus, THC activates a series of events within cancer cells, inhibiting tumor growth.
Despite the imagery that the title of this post (and maybe even casual experience) may imply, it’s not that THC causes cancer cells to ravenously and indiscriminately destroy themselves. Rather, by binding to certain cell-surface receptors, THC activates a cell signaling pathway that leads to cell death. This is a very orderly process, with autophagy just contributing one important step. The authors of this paper work out many of the molecular players in this process, using siRNA and cells derived from knockout mice, although I’ll leave it to the interested reader to further explore that aspect by reading the paper if so inclined.
Mostly, this is interesting (to me) more for the big picture aspect and the implications for clinical medicine. And, of course, for the post title it inspired.
Hat tip to Mo of Neurophilosophy.
Salazar, M., Carracedo, A., Salanueva, I., Hernández-Tiedra, S., Lorente, M., Egia, A., Vázquez, P., Blázquez, C., Torres, S., García, S., Nowak, J., Fimia, G., Piacentini, M., Cecconi, F., Pandolfi, P., González-Feria, L., Iovanna, J., Guzmán, M., Boya, P., & Velasco, G. (2009). Cannabinoid action induces autophagy-mediated cell death through stimulation of ER stress in human glioma cells Journal of Clinical Investigation link