Hypoxia-induced inhibition of the endocannabinoid system in glioblastoma cells.

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“The endocannabinoid system plays an important role in the regulation of physiological and pathological conditions, including inflammation and cancer.

Hypoxia is a fundamental phenomenon for the establishment and maintenance of the microenvironments in various physiological and pathological conditions. However, the influence of hypoxia on the endocannabinoid system is not fully understood. In the present study, we investigated the effects of hypoxia on the endocannabinoid system in malignant brain tumors.

Although cannabinoid receptor (CB) engagement induces cell death in U-87 MG cells in normoxic conditions, CB agonist-induced death was attenuated in hypoxic conditions. These results suggest that hypoxia modifies the endocannabinoid system in glioblastoma cells.

Hypoxia-induced inhibition of the endocannabinoid system may aid the development of glioblastoma.”

https://www.ncbi.nlm.nih.gov/pubmed/29130103

The use of cannabidiol for seizure management in patients with brain tumor-related epilepsy.

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“Epilepsy, commonly encountered by patients with brain tumors, is often refractory to standard therapies. Our aim was to examine the safety and efficacy of pharmaceutical grade cannabidiol (CBD; Epidiolex, GW Pharmaceuticals) in those patients with epilepsy with concomitant tumors enrolled in The University of Alabama at Birmingham CBD Program (NCT02700412 and NCT02695537). Of the three patients with refractory seizures and a history of a primary brain tumor, two had improvement in seizure frequency and all three had improvement in seizure severity. These pilot results suggest that CBD should be further studied for the treatment of brain tumor-related epilepsy.”

https://www.ncbi.nlm.nih.gov/pubmed/29063814

http://www.tandfonline.com/doi/abs/10.1080/13554794.2017.1391294?journalCode=nncs20

A Review of the Therapeutic Antitumor Potential of Cannabinoids.

“The aim of this review is to discuss cannabinoids from a preclinical and clinical oncological perspective and provide the audience with a concise, retrospective overview of the most significant findings concerning the potential use of cannabinoids in cancer treatment.

RESULTS:

Cannabis sativa is a plant rich in more than 100 types of cannabinoids. Besides exogenous plant cannabinoids, mammalian endocannabinoids and synthetic cannabinoid analogues have been identified. Cannabinoid receptors type 1 (CB1) and type 2 (CB2) have been isolated and characterized from mammalian cells. Through cannabinoid receptor and non-receptor signaling pathways, cannabinoids show specific cytotoxicity against tumor cells, while protecting healthy tissue from apoptosis. The dual antiproliferative and proapoptotic effects of cannabinoids and associated signaling pathways have been investigated on a large panel of cancer cell lines. Cannabinoids also display potent anticancer activity against tumor xenografts, including tumors that express high resistance to standard chemotherapeutics. Few studies have investigated the possible synergistic effects of cannabinoids with standard oncology therapies, and are based on the preclinically confirmed concept of “cannabinoid sensitizers.” Also, clinical trials aimed to confirm the antineoplastic activity of cannabinoids have only been evaluated on a small number of subjects, with no consensus conclusions regarding their effectiveness.

CONCLUSIONS:

A large number of cannabinoid compounds have been discovered, developed, and used to study the effects of cannabinoids on cancers in model systems. However, few clinical trials have been conducted on the use of cannabinoids in the treatment of cancers in humans. Further studies require extensive monitoring of the effects of cannabinoids alone or in combination with standard anticancer strategies. With such knowledge, cannabinoids could become a therapy of choice in contemporary oncology.”
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Regulation of human glioblastoma cell death by combined treatment of cannabidiol, γ-radiation and small molecule inhibitors of cell signaling pathways.

Image result for oncotarget “Glioblastoma (GBM) is the most common primary malignant brain tumor in adults. The challenging problem in cancer treatment is to find a way to upregulate radiosensitivity of GBM while protecting neurons and neural stem/progenitor cells in the brain. The goal of the present study was upregulation of the cytotoxic effect of γ-irradiation in GBM by non-psychotropic and non-toxic cannabinoid, cannabidiol (CBD). We emphasized three main aspects of signaling mechanisms induced by CBD treatment (alone or in combination with γ-irradiation) in human GBM that govern cell death: 1) CBD significantly upregulated the active (phosphorylated) JNK1/2 and MAPK p38 levels with the subsequent downregulation of the active phospho-ERK1/2 and phospho-AKT1 levels. MAPK p38 was one of the main drivers of CBD-induced cell death, while death levels after combined treatment of CBD and radiation were dependent on both MAPK p38 and JNK. Both MAPK p38 and JNK regulate the endogenous TRAIL expression. 2) NF-κB p65-P(Ser536) was not the main target of CBD treatment and this transcription factor was found at high levels in CBD-treated GBM cells. Additional suppression of p65-P(Ser536) levels using specific small molecule inhibitors significantly increased CBD-induced apoptosis. 3) CBD treatment substantially upregulated TNF/TNFR1 and TRAIL/TRAIL-R2 signaling by modulation of both ligand and receptor levels followed by apoptosis. Our results demonstrate that radiation-induced death in GBM could be enhanced by CBD-mediated signaling in concert with its marginal effects for neural stem/progenitor cells and astrocytes. It will allow selecting efficient targets for sensitization of GBM and overcoming cancer therapy-induced severe adverse sequelae.”
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