The glioma brain tumor just got a new enemy in the combined power of THC and TMZ. The results show remarkable tumor reduction, when using combination treatment.
Glioblastoma multiforme (GBM), or grade IV glioma brain tumor, is one of the most frequently seen of malignant brain tumors. It is also one of the most aggressive form of cancers, with an average survival rate of 12-15 months, following diagnosis.
Current Treatments are Not Enough
Current treatment includes palliative care, focal radiotherapy, and surgery. Removing the tumor completely is often impossible due to close proximity to vital brain structures. A large number of the chemotherapeutic agents, such as temozolomide(TMZ), have been trialled, but these have limited efficacy. GBM is in desperate need of novel treatments that will increase survival rates, and this could be it!
Combined Therapy Produced Incredible Results
One of the most active areas of cannabis research is in combined treatment, especially for the treatment of cancer. THC combined with TMZ has entered animal trials, resulting in some shockingly positive results.
The basis of THC’s anti-tumor action rests in inducing autophagy within the cancer cell, where cancer essentially targets itself for destruction by lysosomes. Mechanisms of CBD’s anti-cancer action are not as well understood in the glioma brain tumor, but it is speculated that CBD responds to reactive oxygen species that are produced by glioma brain tumor cells. CBD then signals apoptosis of the cancer cells.
To test the efficacy of the THC and TMZ synergistic effects, the tumor bearing mice were injected with the individual agent THC (15mg/kg), TMZ (5mg/kg); and then some mice with the combination of the two (same dose as individual treatment).
The size of the tumor was followed and measured for 15 days. The results were just simply striking! The tumor weight and volume significantly decreased with the combination treatment of the THC + TMZ, significantly more than with each individual treatment.
What is Happening To Kill So Many Glioma Brain Tumor Cells?
The mechanism of the THC and TMZ combination therapy was also evaluated and it was determined that it strongly enhanced the autophagy and apoptosis of the glioma brain tumor cells. This mechanistic study was performed in vitro, using the xenograft cells (the cells from the tumor).
To test if CBD engaged in the similar pathways, combined treatment with the THC and CBD was also tested in vitro. Using submaximal doses, it was determined that the combination of the THC and CBD is as effective as using the THC alone, in reducing the growth of the glioma xenografts.
THC, but not CBD, has been shown to engage cannabinoid receptors to promote tumor cell death. THC triggers de-novo ceramide synthesis which is what stimulates the cell death. It appears that CBD assists THC in setting up autophagy of the cancer cell, but on its own, doesn’t contribute to the reduction of the tumor growth. THC definitively demonstrates contribution to reduction of tumor size in glioblastoma.
The life-threatening issue glioma patients encounter is often resistance to the TMZ agent, which contributes to the poor life prognosis. Patients with this form of brain cancer may see initial results from TMZ, only to have that taper off. The combined treatment, however, of TMZ and cannabinoids, showed tumor growth had been significantly reduced. These results indicate that the presence of cannabinoids overcame the resistance to the TMZ treatment by itself.
These characteristics, along with their remarkable anti-cancer activity, make cannabinoids excellent candidates for combination with other neoplastic agents. Results presented here specifically show that co-administration of TMZ with THC (and THC + CBD), exerts a strong anti-tumor action on glioma xenografts. These results are stronger than individual TMZ treatment or individual cannabinoid therapy.