Cannabinoid Receptors Are Overexpressed in CLL but of Limited Potential for Therapeutic Exploitation

Cannabinoids and triple-negative breast cancer treatment

Triple-negative breast cancer (TNBC) accounts for about 10-20% of all breast cancer cases and is associated with an unfavorable prognosis. Until recently, treatment options for TNBC were limited to chemotherapy. A new successful systemic treatment is immunotherapy with immune checkpoint inhibitors, but new tumor-specific biomarkers are needed to improve patient outcomes. Cannabinoids show antitumor activity in most preclinical studies in TNBC models and do not appear to have adverse effects on chemotherapy. Clinical data are needed to evaluate efficacy and safety in humans. Importantly, the endocannabinoid system is linked to the immune system and immunosuppression. Therefore, cannabinoid receptors could be a potential biomarker for immune checkpoint inhibitor therapy or a novel mechanism to reverse resistance to immunotherapy. In this article, we provide an overview of the currently available information on how cannabinoids may influence standard therapy in TNBC.

Δ9-THC and CBD in Plasma, Oral Fluid, Exhaled Breath, and Urine from 23 Patients Administered Sativex

Background: Detecting the presence of Δ9-THC and CBD is mainly done through venous blood sampling, but other methods are becoming available. Oromucosal administration of Δ9-THC and CBD is less studied than inhalation, but this mode of administration is growing. In this study, we analyze samples obtained through invasive and noninvasive methods in a cohort of patients given oromucosally administered Δ9-THC and CBD to gain understanding in the strengths and weaknesses of the various detection methods. Materials and Methods: Blood, oral fluid (OF), exhaled breath, and urine were collected at several time points from 23 cannabis-naive patients after receiving a single dose of Sativex®; dose ranges: Δ9-THC, 2.7-18.9 mg; CBD 2.5-17.5 mg. Detection of Δ9-THC and CBD was done using liquid chromatography-mass spectrometry methods. Results: Δ9-THC and CBD were present in plasma, OF, and exhaled breath in all 23 patients. The detection time of Δ9-THC and CBD in OF and exhaled breath was longer than in blood. Urine analysis detected the Δ9-THC carboxy metabolite (THC-COOH) up to 7 days after administration, also in a patient who received 8.1/7.5 mg Δ9-THC/CBD. Conclusion: Time to detection of cannabinoids in blood samples was shorter than in exhaled breath and OF. Relative ease of sample collection combined with high sensitivity makes OF and exhaled breath specimens a valuable addition when samples are handled correctly. Δ9-THC metabolites were detected for an unexpected long period of time in urine. EudraCT Number: 2014-005553-39. Date of registration, December 29, 2015.

The evolution of cannabinoid receptors in cancer

Cannabis sativa (cannabis) has been used as a therapeutic treatment for centuries treating various diseases and disorders. However, racial propaganda led to the criminalization of cannabis in the 1930s preventing opportunities to explore marijuana in therapeutic development. The increase in recreational use of cannabis further grew concern about abuse, and lead to further restrictions and distribution of cannabis in the 1970s when it was declared to be a Schedule I drug in the USA. In the late 1990s in some states, legislation assisted in legalizing the use of cannabis for medical purposes under physician supervision. As it has been proven that cannabinoids and their receptors play an essential role in the regulation of the physiological and biological processes in our bodies. The endocannabinoid system (ECS) is the complex that regulates the cell-signaling system consisting of endogenous cannabinoids (endocannabinoids), cannabinoid receptors, and the enzymes responsible for the synthesis and degradation of the endocannabinoids. The ECS along with phytocannabinoids and synthetic cannabinoids serves to be a beneficial therapeutic target in treating diseases as they play roles in cell homeostasis, cell motility, inflammation, pain-sensation, mood, and memory. Cannabinoids have been shown to inhibit proliferation, metastasis, and angiogenesis and even restore homeostasis in a variety of models of cancer in vitro and in vivo. Cannabis and its receptors have evolved into a therapeutic treatment for cancers. This article is categorized under: Cancer > Molecular and Cellular Physiology.

2-Arachidonoylglycerol Modulates CXCL12-Mediated Chemotaxis in Mantle Cell Lymphoma and Chronic Lymphocytic Leukemia

To survive chemotherapy, lymphoma cells can relocate to protective niches where they receive support from the non-malignant cells. The biolipid 2-arachidonoylglycerol (2-AG), an agonist for the cannabinoid receptors CB1 and CB2, is released by stromal cells in the bone marrow. To investigate the role of 2-AG in lymphoma, we analyzed the chemotactic response of primary B-cell lymphoma cells enriched from peripheral blood of twenty-two chronic lymphocytic leukemia (CLL) and five mantle cell lymphoma (MCL) patients towards 2-AG alone and/or to the chemokine CXCL12. The expression of cannabinoid receptors was quantified using qPCR and the protein levels visualized by immunofluorescence and Western blot. Surface expression of CXCR4, the main cognate receptor to CXCL12, was analyzed by flow cytometry. Phosphorylation of key downstream signaling pathways activated by 2-AG and CXCL12 were measured by Western blot in three MCL cell lines and two primary CLL samples. We report that 2-AG induces chemotaxis in 80% of the primary samples, as well as 2/3 MCL cell lines. 2-AG induced in a dose-dependent manner, the migration of JeKo-1 cell line via CB1 and CB2. 2-AG affected the CXCL12-mediated chemotaxis without impacting the expression or internalization of CXCR4. We further show that 2-AG modulated p38 and p44/42 MAPK activation. Our results suggest that 2-AG has a previously unrecognized role in the mobilization of lymphoma cells by effecting the CXCL12-induced migration and the CXCR4 signaling pathways, however, with different effects in MCL compared to CLL.

Cannabinoids as Immune System Modulators: Cannabidiol Potential Therapeutic Approaches and Limitations

Introduction: Cannabidiol (CBD) is the second most abundant Phytocannabinoid in Cannabis extracts. CBD has a binding affinity for several cannabinoid and cannabinoid-associated receptors. Epidiolex (oral CBD solution) has been lately licensed by the Food and Drug Administration (FDA) for the treatment of pediatric epileptic seizures. Methods: In this review, we discussed the most promising applications of CBD for chronic inflammatory conditions, namely CBD's anti-inflammatory effects during inflammatory bowel disease, coronavirus disease (antiviral effect), brain pathologies (neuroprotective and anti-inflammatory properties), as well as CBD immunomodulatory and antitumoral activities in the tumor microenvironment. Special focus was shed on the main therapeutic mechanisms of action of CBD, particularly in the control of the immune system and the endocannabinoid system. Results: Findings suggest that CBD is a potent immunomodulatory drug as it has manifested immunosuppressive properties in the context of sterile inflammation (e.g., inflammatory bowel disease, rheumatoid arthritis, and neurodegenerative diseases), and immunoprotective effects during viral infections (e.g. COVID-19) Similarly, CBD has exhibited a selective response toward cancer types by engaging different targets and signaling pathways. These results are in favor of the primary function of the endocannabinoid system which is homeostatic maintenance. Conclusion: The presented evidence suggests that the endocannabinoid system is a prominent target for the treatment of inflammatory and autoimmune diseases, rheumatoid diseases, viral infections, neurological and psychological pathologies, and cancer. Moreover, the antitumoral activities of CBD have been suggested to be potentially used in combination with chemo- or immunotherapy during cancer. However, clinical results are still lacking, which raises a challenge to apply translational cannabis research to the human immune system.

Use of Cannabis and Cannabinoids for Treatment of Cancer

The endocannabinoid system (ECS) is an ancient homeostasis mechanism operating from embryonic stages to adulthood. It controls the growth and development of many cells and cell lineages. Dysregulation of the components of the ECS may result in uncontrolled proliferation, adhesion, invasion, inhibition of apoptosis and increased vascularization, leading to the development of various malignancies. Cancer is the disease of uncontrolled cell division. In this review, we will discuss whether the changes to the ECS are a cause or a consequence of malignization and whether different tissues react differently to changes in the ECS. We will discuss the potential use of cannabinoids for treatment of cancer, focusing on primary outcome/care-tumor shrinkage and eradication, as well as secondary outcome/palliative care-improvement of life quality, including pain, appetite, sleep, and many more factors. Finally, we will complete this review with the chapter on sex- and gender-specific differences in ECS and response to cannabinoids, and equality of the access to treatments with cannabinoids.

Anti-cancer activities of Schedule E1 drugs used in ayurvedic formulations

Schedule E1 is an important part of Drugs and Cosmetics Act (Government of India) that comprises the list of poisonous drugs from plant, animal and mineral origins to be consumed under medical supervision. Ayurveda, the world's oldest medicinal system has a list of drugs represented in schedule E1 that are used since thousands of years. This review reports the anti-cancer activities of fifteen toxic ayurvedic drugs from plant origin represented in Drugs and Cosmetics Act, 1940. The information was collected from the various authentic sources, compiled and summarised. The plant extracts, formulations, phytoconstituents and other preparations of these drugs have shown effective activities against mammary carcinoma, neuroblastoma, non-small cell lung carcinoma, lymphocytic leukaemia, colorectal adenocarcinoma, Ehrlich ascites carcinoma, prostate adenocarcinoma, glioblastoma asterocytoma and other malignancies. They have various mechanisms of action including Bax upregulation, Bcl2 downregulation, induction of cell cycle arrest at S phase, G2/M phase, inhibition of vascular endothelial growth factors, inhibition of Akt/mTOR signalling etc. Certain traditional ayurvedic preparations containing these plants are reported beneficial and the possibilities of these drugs as the alternative and adjuvant therapeutic agents in the current cancer care have been discussed. The studies suggest that these drugs could be utilised in future for the critical care of malignancies.

Medical Cannabis in Pediatric Oncology: Friend or Foe?

The antineoplastic effects of cannabis have been known since 1975. Since the identification of the components of the endogenous cannabinoid system (ECS) in the 1990s, research into the potential of cannabinoids as medicine has exploded, including in anti-cancer research. However, nearly all of this research has been on adults. Physicians and governing bodies remain cautious in recommending the use of cannabis in children, since the ECS develops early in life and data about cannabis exposure in utero show negative outcomes. However, there exist many published cases of use of cannabis in children to treat pediatric epilepsy and chemotherapy-induced nausea and vomiting (CINV) that show both the safety and efficacy of cannabis in pediatric populations. Additionally, promising preclinical evidence showing that cannabis has anti-cancer effects on pediatric cancer warrants further investigation of cannabis' use in pediatric cancer patients, as well as other populations of pediatric patients. This review aims to examine the evidence regarding the potential clinical utility of cannabis as an anti-cancer treatment in children by summarizing what is currently known about uses of medical cannabis in children, particularly regarding its anti-cancer potential.

Clinical effects of a single dose of cannabinoids to patients with chronic lymphocytic leukemia

This phase II clinical trial investigates a one-time oromucosal dose of tetrahydrocannabinol/cannabidiol (THC/CBD) in 23 patients with indolent leukemic B cell lymphomas. Primary endpoint was a significant reduction in leukemic B cells. Grade 1 - 2 adverse events were seen in 91% of the patients; most common were dry mouth (78%), vertigo (70%), and somnolence (43%). After THC/CBD a significant reduction in leukemic B cells (median, 11%) occurred within two hours (p = .014), and remained for 6 h without induction of apoptosis or proliferation. Normal B cells and T cells were also reduced. CXCR4 expression increased on leukemic cells and T cells. All effects were gone by 24 h. Our results show that a single dose of THC/CBD affects a wide variety of leukocytes and only transiently reduce malignant cells in blood. Based on this study, THC/CBD shows no therapeutic potential for indolent B cell lymphomas (EudraCT trial no. 2014-005553-39).

The Interplay between the Immune and the Endocannabinoid Systems in Cancer

The therapeutic potential of Cannabis sativa has been recognized since ancient times. Phytocannabinoids, endocannabinoids and synthetic cannabinoids activate two major G protein-coupled receptors, subtype 1 and 2 (CB1 and CB2). Cannabinoids (CBs) modulate several aspects of cancer cells, such as apoptosis, autophagy, proliferation, migration, epithelial-to-mesenchymal transition and stemness. Moreover, agonists of CB1 and CB2 receptors inhibit angiogenesis and lymphangiogenesis in vitro and in vivo. Low-grade inflammation is a hallmark of cancer in the tumor microenvironment (TME), which contains a plethora of innate and adaptive immune cells. These cells play a central role in tumor initiation and growth and the formation of metastasis. CB2 and, to a lesser extent, CB1 receptors are expressed on a variety of immune cells present in TME (e.g., T cells, macrophages, mast cells, neutrophils, NK cells, dendritic cells, monocytes, eosinophils). The activation of CB receptors modulates a variety of biological effects on cells of the adaptive and innate immune system. The expression of CB2 and CB1 on different subsets of immune cells in TME and hence in tumor development is incompletely characterized. The recent characterization of the human cannabinoid receptor CB2-G_i signaling complex will likely aid to design potent and specific CB2/CB1 ligands with therapeutic potential in cancer.

Cannabinoids in cancer treatment: Therapeutic potential and legislation

The plant Cannabis sativa L. has been used as an herbal remedy for centuries and is the most important source of phytocannabinoids. The endocannabinoid system (ECS) consists of receptors, endogenous ligands (endocannabinoids) and metabolizing enzymes, and plays an important role in different physiological and pathological processes. Phytocannabinoids and synthetic cannabinoids can interact with the components of ECS or other cellular pathways and thus affect the development/progression of diseases, including cancer. In cancer patients, cannabinoids have primarily been used as a part of palliative care to alleviate pain, relieve nausea and stimulate appetite. In addition, numerous cell culture and animal studies showed antitumor effects of cannabinoids in various cancer types. Here we reviewed the literature on anticancer effects of plant-derived and synthetic cannabinoids, to better understand their mechanisms of action and role in cancer treatment. We also reviewed the current legislative updates on the use of cannabinoids for medical and therapeutic purposes, primarily in the EU countries. In vitro and in vivo cancer models show that cannabinoids can effectively modulate tumor growth, however, the antitumor effects appear to be largely dependent on cancer type and drug dose/concentration. Understanding how cannabinoids are able to regulate essential cellular processes involved in tumorigenesis, such as progression through the cell cycle, cell proliferation and cell death, as well as the interactions between cannabinoids and the immune system, are crucial for improving existing and developing new therapeutic approaches for cancer patients. The national legislation of the EU Member States defines the legal boundaries of permissible use of cannabinoids for medical and therapeutic purposes, however, these legislative guidelines may not be aligned with the current scientific knowledge.

The role of G protein-coupled receptors in lymphoid malignancies

B cell lymphoma consists of multiple individual diseases arising throughout the lifespan of B cell development. From pro-B cells in the bone marrow, through circulating mature memory B cells, each stage of B cell development is prone to oncogenic mutation and transformation, which can lead to a corresponding lymphoma. Therapies designed against individual types of lymphoma often target features that differ between malignant cells and the corresponding normal cells from which they arise. These genetic changes between tumor and normal cells can include oncogene activation, tumor suppressor gene repression and modified cell surface receptor expression. G protein-coupled receptors (GPCRs) are an important class of cell surface receptors that represent an ideal target for lymphoma therapeutics. GPCRs bind a wide range of ligands to relay extracellular signals through G protein-mediated signaling cascades. Each lymphoma subgroup expresses a unique pattern of GPCRs and efforts are underway to fully characterize these patterns at the genetic level. Aberrations such as overexpression, deletion and mutation of GPCRs have been characterized as having causative roles in lymphoma and such studies describing GPCRs in B cell lymphomas are summarized here.