Cancer is one of the most devastating diseases in the animal kingdom. However, mammals have an advantage that other animals don’t have. Mammals are the only animals that have an endocannabinoid system. Incidentally, cancer cells in mammals have higher levels of cannabinoid receptors than the surrounding healthy tissue, so the ECS has more of an effect on these cells.
How is the endocannabinoid system involved in cancer?
Immense volumes of anecdotal evidence have led researchers to pursue whether or not cannabis is effective as a cancer treatment, rather than just as a palliative pain management supplement. The subsequent discovery that almost all types of cancer cells exhibit a high density of CB2 receptors is important because CB2 receptors regulate, among many other things, how quickly our cells produce the immune system chemicals that trigger a process called apoptosis.
Apoptosis, sometimes called programmed cell death, can be viewed as the cellular equivalent to dying of natural causes: over the course of a cell’s life, it produces antigens on its surface. Once it has accumulated enough of these antigens, T- cells treat it like a pathogen and engulf it, keeping only the useful parts. This process occurs in about 80,000,000,000 (Billion) cells every day in the average adult human; it’s absolutely vital to our health and survival, and cancer is defined by the fact that its cells don’t die, they just keep proliferating and growing, which is why tumors are able to form.
When CB2 receptors in cells are activated by endocannabinoids, they inhibit the process of the development of these antigens, which delays apoptosis and allows a cell to stay alive.
Because cancer cells have a high number of CB2 receptors, there is a higher rate of blockage of this process, so cancer cells live much longer than healthy cells. This is what makes them cancerous; normal cells live 5-10 days, but cancer cells can live for 100 days or even longer.
How can CBD and plant cannabinoids help?
CBD and the other cannabinoids play their role by taking advantage of the excess amount of CB2 receptors in cancer cells. It is now becoming clearly understood that when these receptors are activated by endocannabinoids, they inhibit the synthesis (creation) of the enzyme that produces “old age” antigens, which in turn delays apoptosis.
Because cancer cells have a much higher number of CB2 receptors than normal cells, the endocannabinoids they produce have a much greater effect in delaying apoptosis. In fact, the lifespan of tumor cells has shown to be directly correlated to the number of cannabinoid receptors present in the cell: more CB2 receptors = less apoptosis = longer cell lifespan. Cancer cells have around 25 TIMES the CB2 receptors of healthy cells. If only there was a way to reverse the action of these receptors…
A wide range of effects
Phytocannabinoids (cannabinoids from plants) have several different effects on cannabinoid receptors than endocannabinoids (cannabinoids produced in your body). Some phytocannabinoids are antagonists like cannabigerol (CBG), which means they have the opposite effect of the endocannabinoids produced in your cells.
These phytocannabinoids cause the CB2 receptor to change its shape slightly, so it no longer can recognize the presence of the endocannabinoids that are preventing it from triggering the production of the apoptosis enzyme.
Other phytocannabinoids, including CBD, do something else entirely. CBD is a negative allosteric modulator, which means that it binds to the side of the receptor rather than the primary target (allosteric), making it less responsive (negative) to activators (endocannabinoids, THC, etc.) but more responsive to deactivators (like CBG). This has the net effect of causing the cell to produce more of the old age antigens, especially in the presence of other plant cannabinoids like CBG.
This negative response is magnified just like the action of endocannabinoids is magnified, due to the inordinately high number of CB2 receptors expressed in cancer cells. Thus, phytocannabinoids have an anti-cancer effect that increases with the number of CB2 receptors exhibited in the cancerous tissue.
In this manner, it appears that cannabis-based treatments actually target cancer cells specifically, because of their extremely high number of CB2 receptors and the crucial role they play in programmed cell death.