Molecular Mechanism of Autophagy and Its Regulation by Cannabinoids in Cancer

cancers-logo“Autophagy is a “self-degradation” process whereby malfunctioned cytoplasmic constituents and protein aggregates are engulfed by a vesicle called the autophagosome, and subsequently degraded by the lysosome. Autophagy plays a crucial role in sustaining protein homeostasis and can be an alternative source of energy under detrimental circumstances. Studies have demonstrated a paradoxical function for autophagy in cancer, displaying both tumour suppressive and tumour promotive roles. In early phases of tumour development autophagy promotes cancer cell death. In later phases, autophagy enables cancer cells to survive and withstand therapy.

Cannabinoids, which are derivatives of the Cannabis sativa L. plant, have shown to be associated with autophagy induction in cells. There is an emerging interest in studying the signalling pathways involved in cannabinoid-induced autophagy and their potential application in anticancer therapies. In this review, the molecular mechanisms involved in the autophagy degradation process will be discussed. This review also highlights a role for autophagy in cancer progression, with cannabinoid-induced autophagy presenting a novel strategy for anticancer therapy.”

https://pubmed.ncbi.nlm.nih.gov/33802014/

“This review examines the complex function of autophagy in malignancy and explores its regulation by cannabinoids in different cancers. Autophagy is an important process in the maintenance of cellular homeostasis, through the degradation and recycling of cytoplasmic constituents. The action of autophagy is highly dependent on tumour stage and type and the receptors with which ligands interact. Cannabinoids are growingly being acknowledged for their anticancer activities and are known to stimulate several mechanisms such as apoptosis and autophagy. Better understanding the mechanism of action behind autophagy and its regulation by cannabinoids will allow the development of novel cancer therapeutics.”

Efficacy of cannabinoids against glioblastoma multiforme: A systematic review

Phytomedicine

“INTRODUCTION

: The increased incidence of Glioblastoma Multiforme, the most aggressive and most common primary brain tumour, is evident worldwide. Survival rates are reaching only 15 months due to its high recurrence and resistance to current combination therapies including oncotomy, radiotherapy and chemotherapy. Light has been shed in the recent years on the anticancer properties of cannabinoids from Cannabis sativa.

OBJECTIVE

: To determine whether cannabinoids alone or in combination with radiotherapy and/or chemotherapy inhibit tumour progression, induce cancer cell death, inhibit metastasis and invasiveness and the mechanisms that underlie these actions.

METHOD

: PubMed and Web of Science were used for a systemic search to find studies on the anticancer effects of natural cannabinoids on glioma cancer cells in vitro and/or in vivo.

RESULTS

: A total of 302 papers were identified, of which 14 studies were found to fit the inclusion criteria. 5 studies were conducted in vitro, 2 in vivo and 7 were both in vivo and in vitro. 3 studies examined the efficacy of CBD, THC and TMZ, 1 study examined CBD and radiation, 2 studies examined efficacy of THC only and 3 studies examined the efficacy of CBD only. 1 study examined the efficacy of CBD, THC and radiotherapy, 2 studies examined the combination of CBD and THC and 2 more studies examined the efficacy of CBD and TMZ.

CONCLUSION

: The evidence in this systematic review leads to the conclusion that cannabinoids possess anticancer potencies against glioma cells, however this effect varies with the combinations and dosages used. Studies so far were conducted on cells in culture and on mice as well as a small number of studies that were conducted on humans. Hence in order to have more accurate results, higher quality studies mainly including human clinical trials with larger sample sizes are necessitated urgently for GBM treatment.”

HTTPS://WWW.SCIENCEDIRECT.COM/SCIENCE/ARTICLE/ABS/PII/S0944711321000751

The effect of cannabis in the treatment of Hodgkin’s lymphoma in a pregnant patient – extensive case report and literature review

pubmed logo“Purpose: Hodgkin lymphoma (HL) is the fourth most frequent cancer diagnosis among pregnant females. A multidisciplinary team is mandatory to obtain the best treatment and prognosis for the mother and for the baby. Here, we present the case of a patient diagnosed with HL and its evolution during 2 pregnancies.

Case presentation: Herein we present the case of a 21-year-old female Caucasian patient, with free history, diagnosed with HL stage IIB. The patient started first line chemotherapy and radiotherapy, with incomplete remission. She refused any other treatment. Five years later, the patient became pregnant and was offered chemotherapy in the 2nd trimester of pregnancy, that she refused, and delivered by C-section at 37 weeks. In the same year, the patient became pregnant again and was proposed termination of pregnancy, that she also refused. The MRI scan revealed progression of HL and she was admitted in the hospital several times for altered general condition, respiratory infections and increased need of painkillers including opioids.

At 26 weeks of pregnancy, the patient began on her own a treatment with pure cannabis. Her pain and general status got better and the tumor tissue decreased.

She delivered by C-section at 34 weeks a boy that presented in the first 24 h postpartum a withdrawal syndrome and intestinal invagination, requiring care in NICU and surgery with bowel resection.

Conclusion: Therefore, we can conclude that cannabis could be part of oncological treatment. No other case like this, as far as we know, has been previously reported.”

Unveiling the mechanism of action behind the anti-cancer properties of cannabinoids in ER + breast cancer cells: impact on aromatase and steroid receptors

The Journal of Steroid Biochemistry and Molecular Biology“Breast cancer is the leading cause of cancer-related death in women worldwide. In the last years, cannabinoids have gained attention in the clinical setting and clinical trials with cannabinoid-based preparations are underway. However, contradictory anti-tumour properties have also been reported. Thus, the elucidation of the molecular mechanisms behind their anti-tumour efficacy is crucial to better understand its therapeutic potential.

Considering this, our work aims to clarify the molecular mechanisms underlying the anti-cancer properties of the endocannabinoid anandamide (AEA) and of the phytocannabinoids, cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC), in estrogen receptor-positive (ER+) breast cancer cells that overexpress aromatase (MCF-7aro). Their in vitro effects on cell proliferation, cell death and activity/expression of aromatase, ERα, ERβ and AR were investigated.

Our results demonstrated that cannabinoids disrupted MCF-7aro cell cycle progression. Unlike AEA and THC that induced apoptosis, CBD triggered autophagy to promote apoptotic cell death. Interestingly, all cannabinoids reduced aromatase and ERα expression levels in cells. On the other hand, AEA and CBD not only exhibited high anti-aromatase activity but also induced up-regulation of ERβ. Therefore, all cannabinoids, albeit by different actions, target aromatase and ERs, impairing, in that way, the growth of ER+ breast cancer cells, which is dependent on estrogen signalling.

As aromatase and ERs are key targets for ER+ breast cancer treatment, cannabinoids can be considered as potential and attractive therapeutic compounds for this type of cancer, being CBD the most promising one. Thus, from an in vitro perspective, this work may contribute to the growing mass of evidence of cannabinoids and cannabinoids-based medicines as potential anti-cancer drugs.”

https://pubmed.ncbi.nlm.nih.gov/33722705/

“AEA and THC induce apoptosis in ER+ breast cancer cells, while CBD trigger autophagy to promote apoptosis. AEATHC and CBD impair growth of ER+ breast cancer cells, by disrupting cycle progression. AEATHC and CBD affect aromatase and ERα expression levels in ER+ breast cancer cells. AEA and CBD strongly inhibited aromatase activity and up-regulated ERβ levels. Cannabinoids are considered potential therapeutic compounds for ER+ breast cancer, being CBD the most promising one.”

https://www.sciencedirect.com/science/article/abs/pii/S0960076021000698?via%3Dihub

Emerging role of cannabinoids and synthetic cannabinoid receptor 1/cannabinoid receptor 2 receptor agonists in cancer treatment and chemotherapy-associated cancer management

 Journal of Cancer Research and Therapeutics“Cannabis was extensively utilized for its medicinal properties till the 19th century. A steep decline in its medicinal usage was observed later due to its emergence as an illegal recreational drug. Advances in technology and scientific findings led to the discovery of delta-9-tetrahydrocannabinol (THC), the primary psychoactive compound of cannabis, that further led to the discovery of endogenous cannabinoids system consisting of G-protein-coupled receptors – cannabinoid receptor 1 and cannabinoid receptor 2 along with their ligands, mainly anandamide and 2-arachidonoylglycerol. Endocannabinoid (EC) is shown to be a modulator not only for physiological functions but also for the immune system, endocrine network, and central nervous system. Medicinal research and meta-data analysis over the last few decades have shown a significant potential for both THC and cannabidiol (CBD) to exert palliative effects. People suffering from many forms of advanced stages of cancers undergo chemotherapy-induced nausea and vomiting followed by severe and chronic neuropathic pain and weight loss. THC and CBD exhibit effective analgesic, anxiolytic, and appetite-stimulating effect on patients suffering from cancer. Drugs currently available in the market to treat such chemotherapy-induced cancer-related ailments are Sativex (GW Pharmaceutical), Dronabinol (Unimed Pharmaceuticals), and Nabilone (Valeant Pharmaceuticals). Apart from exerting palliative effects, THC also shows promising role in the treatment of cancer growth, neurodegenerative diseases (multiple sclerosis and Alzheimer’s disease), and alcohol addiction and hence should be exploited for potential benefits. The current review discusses the nature and role of CB receptors, specific applications of cannabinoids, and major studies that have assessed the role of cannabinoids in cancer management.”

https://pubmed.ncbi.nlm.nih.gov/33723124/

“Specific targeting of cannabinoid receptors can be used to manage severe side effects during chemotherapy, palliative care, and overall cancer management. Furthermore, research evidences on cannabinoids have suggested tumor inhibiting and suppressing properties which warrant reconsidering legality of the substance. Studies on CB1 and CB2 receptors, in case of cancers, have demonstrated the psychoactive constituents of cannabinoids to be potent against tumor growth. Interestingly, studies have also shown that activation of CB1 and CB2 cannabinoid receptors by their respective synthetic agonists tends to limit human cancer cell growth, suggesting the role of the endocannabinoid system as a novel target for treatment of cancers.”

https://www.cancerjournal.net/article.asp?issn=0973-1482;year=2021;volume=17;issue=1;spage=1;epage=9;aulast=Shah

A cannabidiol-loaded Mg-gallate metal-organic framework-based potential therapeutic for glioblastomas

 “Cannabidiol (CBD) has been shown to slow cancer cell growth and is toxic to human glioblastoma cell lines. Thus, CBD could be an effective therapeutic for glioblastoma.

In the present study, we explored the anticancer effect of cannabidiol loaded magnesium-gallate (CBD/Mg-GA) metal-organic framework (MOF) using the rat glioma brain cancer (C6) cell line.

Bioactive and microporous magnesium gallate MOF was employed for simultaneous delivery of two potential anticancer agents (gallic acid and CBD) to the cancer cells. Gallic acid (GA), a polyphenolic compound, is part of the MOF framework, while CBD is loaded within the framework. Slow degradation of CBD/Mg-GA MOF in physiological fluids leads to sustained release of GA and CBD.

CBD’s anti-cancer actions target mitochondria, inducing their dysfunction and generation of harmful reactive oxygen species (ROS). Anticancer effects of CBD/Mg-GA include a significant increase in ROS production and a reduction in anti-inflammatory responses as reflected by a significant decrease in TNF-α expression levels. Molecular mechanisms that underlie these effects include the modulation of NF-κB expression, triggering the apoptotic cascades of glioma cells. CBD/Mg-GA MOF has potential anti-cancer, anti-inflammatory and anti-oxidant properties.

Thus, the present study demonstrates that CBD/Mg-GA MOF may be a promising therapeutic for glioblastoma.”

https://pubmed.ncbi.nlm.nih.gov/33657198/

https://pubs.rsc.org/en/content/articlelanding/2021/TB/D0TB02780D#!divAbstract

Graphical abstract: A cannabidiol-loaded Mg-gallate metal–organic framework-based potential therapeutic for glioblastomas

The pro-apoptosis effects of Echinacea purpurea and Cannabis sativa extracts in human lung cancer cells through caspase-dependent pathway

 Logo of bmccmt“Considering the advantages of using medicinal herbs as supplementary treatments to sensitize conventional anti-cancer drugs, studying functional mechanisms and regulatory effects of Echinacea purpurea (as a non-cannabinoid plant) Image result for echinacea purpurea

and Cannabis sativa (as a cannabinoid plant) are timely and required.Image result for cannabis sativa

The potential effects of such herbs on lung cancer cell growth, apoptosis, cell cycle distribution, cellular reactive oxygen species (ROS) level, caspase activity and their cannabinomimetic properties on the CB2 receptor are addressed in the current study.

Results: Echinacea purpurea (EP) root extract induced a considerable decrease in A549 viable cells, showing a time and dose-dependent response. The cell toxicity of EP was accompanied by induction of early apoptosis and cell accumulation at the sub G1 phase of the cell cycle. The elevation of cellular ROS level and caspase 3 activity indicate ROS-induced caspase-dependent apoptosis following the treatment of A549 cells by EP extract. The observed effects of EP extract on A549 growth and death were abrogated following blockage of CB2 using AM630, a specific antagonist of the CB2 receptor. Increasing concentrations of Cannabis sativa (CS) induced A549 cell death in a time-dependent manner, followed by induction of early apoptosis, cell cycle arrest at sub G1 phase, elevation of ROS level, and activation of caspase 3. The CB2 blockage caused attenuation of CS effects on A549 cell death which revealed consistency with the effects of EP extract on A549 cells.

Conclusions: The pro-apoptotic effects of EP and CS extracts on A549 cells and their possible regulatory role of CB2 activity might be attributed to metabolites of both herbs. These effects deserve receiving more attention as alternative anti-cancer agents.”

https://pubmed.ncbi.nlm.nih.gov/33446187/

“Both cannabinoid receptors and naturally occurring cannabinoids, known as phytocannabinoids, have potential therapeutic applications based on their pivotal roles in regulating immunologic responses, alleviating inflammation, tumor cell proliferation, angiogenesis, invasion, and migration. Based on the findings, it can be postulated that EP and CS extracts can inhibit lung cancer cell growth and induce apoptosis and should be considered as an alternative anti-cancer agent in lung cancer.”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7809807/

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The Role of Cannabinoids as Anticancer Agents in Pediatric Oncology

cancers-logo“Cannabinoids are a group of chemicals that bind to receptors in the human body and, in turn, modulate the endocannabinoid system (ECS). They can be endogenously produced, synthetic, or derived from the plant Cannabis sativa L.

Research over the past several decades has shown that the ECS is a cellular communication network essential to maintain multiple biological functions and the homeostasis of the body. Indeed, cannabinoids have been shown to influence a wide variety of biological effects, including memory, pain, reproduction, bone remodeling or immunity, to name a few.

Unsurprisingly, given these broad physiological effects, alterations of the ECS have been found in different diseases, including cancer. In recent years, the medical use of cannabis has been approved in different countries for a variety of human conditions. However, the use of these compounds, specifically as anticancer agents, remains controversial.

Studies have shown that cannabinoids do have anticancer activity in different tumor types such as breast cancer, melanoma, lymphoma and adult brain cancer. Specifically, phytocannabinoids Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) has been shown to induce apoptosis and inhibit proliferation of adult cancer cells, as well as modulate angiogenesis and metastasis.

Despite increasing evidence that cannabinoids elicit antitumor effects in adult cancers, there is minimal data available on their effects in children or in pediatric cancers despite public and clinical demand for information. Here we describe a comprehensive and critical review of what is known about the effects of cannabinoids on pediatric cancers, highlight current gaps in knowledge and identify the critical issues that need addressing before considering these promising but controversial drugs for use in pediatric oncology.”

https://pubmed.ncbi.nlm.nih.gov/33466435/

https://www.mdpi.com/2072-6694/13/1/157

Cannabis-Derived Compounds Cannabichromene and Δ9-Tetrahydrocannabinol Interact and Exhibit Cytotoxic Activity against Urothelial Cell Carcinoma Correlated with Inhibition of Cell Migration and Cytoskeleton Organization

molecules-logo“Cannabis sativa contains more than 500 constituents, yet the anticancer properties of the vast majority of cannabis compounds remains unknown. We aimed to identify cannabis compounds and their combinations presenting cytotoxicity against bladder urothelial carcinoma (UC), the most common urinary system cancer.

An XTT assay was used to determine cytotoxic activity of C. sativa extracts on T24 and HBT-9 cell lines. Extract chemical content was identified by high-performance liquid chromatography (HPLC). Fluorescence-activated cell sorting (FACS) was used to determine apoptosis and cell cycle, using stained F-actin and nuclei. Scratch and transwell assays were used to determine cell migration and invasion, respectively. Gene expression was determined by quantitative Polymerase chain reaction (PCR).

The most active decarboxylated extract fraction (F7) of high-cannabidiol (CBD) C. sativa was found to contain cannabichromene (CBC) and Δ9-tetrahydrocannabinol (THC). Synergistic interaction was demonstrated between CBC + THC whereas cannabinoid receptor (CB) type 1 and type 2 inverse agonists reduced cytotoxic activity.

Treatments with CBC + THC or CBD led to cell cycle arrest and cell apoptosis. CBC + THC or CBD treatments inhibited cell migration and affected F-actin integrity. Identification of active plant ingredients (API) from cannabis that induce apoptosis and affect cell migration in UC cell lines forms a basis for pre-clinical trials for UC treatment.”

https://pubmed.ncbi.nlm.nih.gov/33477303/

https://www.mdpi.com/1420-3049/26/2/465

Therapeutic potential of cannabinoids in combination cancer therapy

 Advances in Biological Regulation“Derivatives of the plant Cannabis sativa have been used for centuries for both medical and recreational purposes, as well as industrial. The first proof of its medicinal use comes from ancient China, although there is evidence of its earlier utilization in Europe and Asia. In the 19th century, European practitioners started to employ cannabis extracts to treat tetanus, convulsions, and mental diseases and, in 1851, cannabis made its appearance in the Pharmacopoeia of the United States as an analgesic, hypnotic and anticonvulsant. It was only in 1937 that the Marijuana Tax Act prohibited the use of this drug in the USA. The general term Cannabis is commonly used by the scientific and scholar community to indicate derivatives of the plant Cannabis sativa. The word cannabinoid is a term describing chemical compounds that are either derivate of Cannabis (phytocannabinoids) or artificial analogues (synthetic) or are produced endogenously by the body (endocannabinoids). A more casual term “marijuana” or “weed”, a compound derived from dried Cannabis flower tops and leaves, has progressively superseded the term cannabis when referred to its recreational use. The 2018 World health organisation (WHO) data suggest that nearly 2.5% of the global population (147 million) uses marijuana and some countries, such as Canada and Uruguay, have already legalised it. Due to its controversial history, the medicinal use of cannabinoids has always been a centre of debate. The isolation and characterisation of Δ9 tetrahydrocannabinol (THC), the major psychoactive component of cannabis and the detection of two human cannabinoid receptor (CBRs) molecules renewed interest in the medical use of cannabinoids, boosting research and commercial heed in this sector. Some cannabinoid-based drugs have been approved as medications, mainly as antiemetic, antianorexic, anti-seizure remedies and in cancer and multiple sclerosis patients’ palliative care. Nevertheless, due to the stigma commonly associated with these compounds, cannabinoids’ potential in the treatment of conditions such as cancer is still largely unknown and therefore underestimated.”

https://pubmed.ncbi.nlm.nih.gov/33422460/

https://www.sciencedirect.com/science/article/abs/pii/S2212492620300853?via%3Dihub