"The Weed"

I'm a little late on it, however this journal article proposes Δ⁹-tetrahydrocannabinol (that is, the agent found in marijuana, THC) has a profound impact on human glioma, a cancer of the brain and spine. The following is the abstract from the article:

Autophagy can promote cell survival or cell death, but the molecular basis underlying its dual role in cancer remains obscure. Here we demonstrate that Δ⁹-tetrahydrocannabinol (THC), the main active component of marijuana, induces human glioma cell death through stimulation of autophagy. Our data indicate that THC induced ceramide accumulation and eukaryotic translation initiation factor 2α (eIF2α) phosphorylation and thereby activated an ER stress response that promoted autophagy via tribbles homolog 3–dependent (TRB3-dependent) inhibition of the Akt/mammalian target of rapamycin complex 1 (mTORC1) axis. We also showed that autophagy is upstream of apoptosis in cannabinoid-induced human and mouse cancer cell death and that activation of this pathway was necessary for the antitumor action of cannabinoids in vivo. These findings describe a mechanism by which THC can promote the autophagic death of human and mouse cancer cells and provide evidence that cannabinoid administration may be an effective therapeutic strategy for targeting human cancers.

What this means is that THC, from marijuana, caused an accumulation of a lipid molecule called ceramide, which is instrumental in regulating cell death. This accumulation induced an ER stress response, which regards the cell organelle the endoplasmic reticulum that is responsible for folding and transporting proteins for proper use within the cell . This stress response is such that too many proteins are unfolded or misfolded, triggering the cell to halt normal function such as translation (genetic reproduction) until a homeostasis is reached. When this homeostasis is not reached, it induces autophagy, essentially a form of cell death. Thus, the findings indicate that marijuana is effective in treating cancer cells.