Cannabidiol inhibits lung cancer cell invasion and metastasis via intercellular adhesion molecule-1

Cannabinoids in Medicine: Cancer, Immunity, and Microbial Diseases

Recently, there has been a growing interest in the medical applications of Cannabis plants. They owe their unique properties to a group of secondary metabolites known as phytocannabinoids, which are specific for this genus. Phytocannabinoids, and cannabinoids generally, can interact with cannabinoid receptors being part of the endocannabinoid system present in animals. Over the years a growing body of scientific evidence has been gathered, suggesting that these compounds have therapeutic potential. In this article, we review the classification of cannabinoids, the molecular mechanisms of their interaction with animal cells as well as their potential application in the treatment of human diseases. Specifically, we focus on the research concerning the anticancer potential of cannabinoids in preclinical studies, their possible use in cancer treatment and palliative medicine, as well as their influence on the immune system. We also discuss their potential as therapeutic agents in infectious, autoimmune, and gastrointestinal inflammatory diseases. We postulate that the currently ongoing and future clinical trials should be accompanied by research focused on the cellular and molecular response to cannabinoids and Cannabis extracts, which will ultimately allow us to fully understand the mechanism, potency, and safety profile of cannabinoids as single agents and as complementary drugs.

A gene-based survival score for lung adenocarcinoma by multiple transcriptional datasets analysis

Background

Lung adenocarcinoma (LUAD) remains a crucial factor endangering human health. Gene-based clinical predictions could be of great help for cancer intervention strategies. Here, we tried to build a gene-based survival score (SS) for LUAD via analyzing multiple transcriptional datasets.

Methods

We first acquired differentially expressed genes between tumors and normal tissues from intersections of four LUAD datasets. Next, survival-related genes were preliminarily unscrambled by univariate Cox regression and further filtrated by LASSO regression. Then, we applied PCA to establish a comprehensive SS based on survival-related genes. Subsequently, we applied four independent LUAD datasets to evaluate prognostic prediction of SS. Moreover, we explored associations between SS and clinicopathological features. Furthermore, we assessed independent predictive value of SS by multivariate Cox analysis and then built prognostic models based on clinical stage and SS. Finally, we performed pathway enrichments analysis and investigated immune checkpoints expression underlying SS in four datasets.

Results

We established a 13 gene-based SS, which could precisely predict OS and PFS of LUAD. Close relations were elicited between SS and canonical malignant indictors. Furthermore, SS could serve as an independent risk factor for OS and PFS. Besides, the predictive efficacies of prognostic models were also reasonable (C-indexes: OS, 0.7; PFS, 0.7). Finally, we demonstrated enhanced cell proliferation and immune escape might account for high clinical risk of SS.

Conclusions

We built a 13 gene-based SS for prognostic prediction of LUAD, which exhibited wide applicability and could contribute to LUAD management.

Cannabidiol (CBD) as a Promising Anti-Cancer Drug

Recently, cannabinoids, such as cannabidiol (CBD) and Δ9 -tetrahydrocannabinol (THC), have been the subject of intensive research and heavy scrutiny. Cannabinoids encompass a wide array of organic molecules, including those that are physiologically produced in humans, synthesized in laboratories, and extracted primarily from the Cannabis sativa plant. These organic molecules share similarities in their chemical structures as well as in their protein binding profiles. However, pronounced differences do exist in their mechanisms of action and clinical applications, which will be briefly compared and contrasted in this review. The mechanism of action of CBD and its potential applications in cancer therapy will be the major focus of this review article.

The pharmacological basis for application of cannabidiol in cancer chemotherapy

Chemotherapy is one of the therapeutic approaches for cancer treatment and has demonstrated great success with the introduction of selectively acting molecules against specific biomarkers of some types of tumors. Despite this success there is a large unmet need for novel therapies that provide effective control on the progression of advanced or drug-resistant cancer diseases. In this review, we briefly summarized our knowledge of cannabinoids and the endocannabinoid system, as possible agents for cancer therapy. We analyzed the anticancer properties and mechanism of action of cannabidiol (CBD), the main non-psychoactive cannabinoid received from hemp of Cannabis plant. Despite of data for pleiotropic effects of CBD, we here present the results for the efficacy of CBD in the modulation of different stages of cancer development. The analysis of the anticancer properties of CBD is made in relation to the proposed or newly discovered molecular targets of action. Thereafter, we consider the specific effects of CBD on primary tumors, their invasiveness and metastases, whether the influence on identified tumor markers in different types of tumors reflect the therapeutic potential of CBD. The studies reviewed herein indicate that CBD elicit activity through the cannabinoid receptor dependent and independent pathways. The processes such as ceramide production, ER-stress, autophagy and apoptosis, angiogenesis and matrix remodeling also appear to regulate the anticancer activity of CBD. So, the pharmacological basis for therapeutic application of CBD is constructed on the scientific data for its antitumor activity, extensively provided studies in vitro and in vivo in animal tumor models, and available data on the safety profile of clinically approved CBD products. We also try to reduce the deficits of our understanding in relation of pharmacological synergistic interactions of CBD with cytostatic drugs, where data remains limited. It is recognized that more studies for defining the specific molecular and signaling mechanisms of anticancer action of cannabinoids, particularly CBD, requires further evaluation. We believe that the therapeutic advantages of CBD are associated not only with its non-psychoactive behavior, but also are related to its influence on the important biochemical pathways and signal molecules, defining the genome instability and specific changes of the malignant tumor cells.

The Effects of Cannabidiol and Prognostic Role of TRPV2 in Human Endometrial Cancer

Several studies support, both in vitro and in vivo, the anti-cancer effects of cannabidiol (CBD), a transient receptor potential vanilloid 2 (TRPV2) ligand. TRPV2, often dysregulated in tumors, is associated with altered cell proliferation and aggressiveness. Endometrial cancer (EC) is historically divided in type I endometrioid EC and type II non-endometrioid EC, associated with poor prognosis. Treatment options with chemotherapy and combinations with radiation showed only limited efficacy. Since no data are reported concerning TRPV2 expression as well as CBD potential effects in EC, the aim of this study was to evaluate the expression of TRPV2 in biopsies and cell lines as well as the effects of CBD in in vitro models. Overall survival (OS), progression-free survival (PFS), cell viability, migration, and chemo-resistance have been evaluated. Results show that TRPV2 expression increased with the malignancy of the cancer tissue and correlated with shorter PFS (p = 0.0224). Moreover, in vitro TRPV2 over-expression in Ishikawa cell line increased migratory ability and response to cisplatin. CBD reduced cell viability, activating predominantly apoptosis in type I cells and autophagy in mixed type EC cells. The CBD improved chemotherapeutic drugs cytotoxic effects, enhanced by TRPV2 over-expression. Hence, TRPV2 could be considered as a marker for optimizing the therapy and CBD might be a useful therapeutic option as adjuvant therapy.

[Cannabidiol in cancer treatment]

BACKGROUND

Cannabis was used for cancer patients as early as about 2500 years ago. Experimental studies demonstrated tumor-inhibiting activities of various cannabinoids more than 40 years ago. In view of the status of tetrahydrocannabinol (THC) as a regulated substance, non-psychotomimetic cannabidiol (CBD) is of particular importance.

OBJECTIVES

Efficacy of pure CBD in various animal models as well as initial results (case reports) from patients.

METHODS

Review of the literature on animal experiments and observations in humans.

RESULTS

Preclinical studies, particularly recent ones, including numerous animal models of tumors, unanimously suggest the therapeutic efficacy of CBD. In isolated combination studies, synergistic effects were generally observed. In addition, CBD may potentially play a role in the palliative care of patients, especially concerning symptoms such as pain, insomnia, anxiety, and depression. Further human studies are warranted.

Electrochemical Assessment of Anticancer Compounds on the Human Tongue Squamous Carcinoma Cells

The most common oral cancer is squamous cell carcinoma (SCC) and its highest occurrence is in the tongue. Almost 30% of patients with one primary head and neck tumor will have a second primary malignancy. In recent studies, two novel plant extracts, andrographolide and cannabidiol (CBD), have been exploited for their anticancer effects. Here, we investigated the cytotoxic effects of these two compounds on SCC-25 cells, a human tongue squamous carcinoma cell line, and compared the outcomes with two chemotherapeutic drugs, cisplatin and fluorouracil. Electric cell substrate impedance sensing (ECIS) system was applied to measure frequency- and time-dependent impedance of SCC-25 cell-covered electrodes and to further assess subtle changes in cell morphology and micromotion in response to different concentrations (0, 10, 30, 100, and 300 µM) of these compounds. AlamarBlue and Annexin V/7-AAD binding assays were used to measure the concentration dependent changes in viability and apoptosis of SCC-25 cells. Our results demonstrate that 24 hours after exposure to 30 µM CBD can significantly decrease the micromotion rate, damage the integrity of cell morphology, reduce cell viability, and induce higher apoptosis in treated SCC-25 cells, while the other three drugs attain similar effects at the concentration of 100 µM or higher. The apoptosis-induced changes in cell morphology and micromotion monitored by ECIS correlate well with biochemical assays. Thus, both frequency- and time-dependent impedance measurements using ECIS can be used to real-time follow cancer cell activities in response to anticancer drugs with different temporal cytotoxicity profiles.

Selective Extraction of Cannabinoid Compounds from Cannabis Seed Using Pressurized Hot Water Extraction

Phytochemicals of Cannabis sativa mainly for the use in the different industries are that of delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). Pressurized hot water extraction (PHWE) is seen as an efficient, fast, green extraction technique for the removal of polar and semi-polar compounds from plant materials. The PHWE technique was applied to extract cannabinoid compounds from Cannabis sativa seed. Response surface methodology was used to investigate the influence of extraction time (5-60 min), extraction temperature (50-200 °C) and collector vessel temperature (25-200 °C) on the recovery of delta-9-tetrahydrocannabinol (THC), cannabinol (CBN), cannabidiol (CBD), cannabichromene (CBG) and cannabigerol (CBC) from Cannabis sativa seed by PHWE. The identification and semi quantification of cannabinoid compounds were determined using GCXGC-TOFMS. The results obtained from different extractions show that the amount of THC and CBN was drastically decreasing in the liquid extract when the temperature rose from 140 to 160 °C in the extraction cell and the collector's vessel. The optimal conditions to extract more CBD, CBC, and CBG than THC and CBN were set at 150 °C, 160 °C and 45 min as extraction temperature, the temperature at collector vessel, and the extraction time, respectively. At this condition, the predicted and experimental ratio of THCt (THC + CBN)/CBDt (CBD + CBC+ CBG) was found to be 0.17 and 0.18, respectively. Therefore, PHWE can be seen as an alternative to the classic extraction approach as the efficiency is higher and it is environmentally friendly.

The evaluation of Cannabidiol's effect on the immunotherapy of Burkitt lymphoma

AIM

AF1q has a precise oncogenic function. The purpose of this study is to investigate whether CBD has an effect on the AF1q/ICAM-1 regulatory axis in Burkitt's lymphoma (BL), and thus has potential to enhance immunotherapy and reduce side effects.

METHODS

We established BL cell lines with altered AF1q expression using lentivirus. After confirmation of gene expression by RT-PCR, cells were treated with CBD followed by co-culture of killing assay.

RESULTS

AF1q increased oncogenic growth and colony formation, and induced resistance against cell-mediated cytotoxic chemotherapy through attenuation of ICAM-1 expression in BL. CBD was able to reverse the acquired resistance mediated by AF1q/ICAM-1 regulatory axis.

CONCLUSION

CBD holds potential to enhance the efficacy of immunotherapy for BL with hyperactive AF1q/ICAM-1 regulatory axis, and warrants further study.

Enhancing Breast Cancer Treatment Using a Combination of Cannabidiol and Gold Nanoparticles for Photodynamic Therapy

Indisputably, cancer is a global crisis that requires immediate intervention. Despite the use of conventional treatments over the past decades, it is acceptable to admit that these are expensive, invasive, associated with many side effects and, therefore, a reduced quality of life. One of the most possible solutions to this could be the use of gold nanoparticle (AuNP) conjugated photodynamic therapy (PDT) in combination with cannabidiol (CBD), a Cannabis derivative from the Cannabis sativa. Since the use of Cannabis has always been associated with recreation and psychoactive qualities, the positive effects of Cannabis or its derivatives on cancer treatment have been misunderstood and hence misinterpreted. On the other hand, AuNP-PDT is the most favoured form of treatment for cancer, due to its augmented specificity and minimal risk of side effects compared to conventional treatments. However, its use requires the consideration of several physical, biologic, pharmacologic and immunological factors, which may hinder its effectiveness if not taken into consideration. In this review, the role of gold nanoparticle mediated PDT combined with CBD treatment on breast cancer cells will be deliberated.

Differential Expression Profiles of the Transcriptome and miRNA Interactome in Synovial Fibroblasts of Rheumatoid Arthritis Revealed by Next Generation Sequencing

Using next-generation sequencing to decipher the molecular mechanisms underlying aberrant rheumatoid arthritis synovial fibroblasts (RASF) activation, we performed transcriptome-wide RNA-seq and small RNA-seq on synovial fibroblasts from rheumatoid arthritis (RA) subject and normal donor. Differential expression of mRNA and miRNA was integrated with interaction analysis, functional annotation, regulatory network mapping and experimentally verified miRNA–target interaction data, further validated with microarray expression profiles. In this study, 3049 upregulated mRNA and 3552 downregulated mRNA, together with 50 upregulated miRNA and 35 downregulated miRNA in RASF were identified. Interaction analysis highlighted contribution of miRNA to altered transcriptome. Functional annotation revealed metabolic deregulation and oncogenic signatures of RASF. Regulatory network mapping identified downregulated FOXO1 as master transcription factor resulting in altered transcriptome of RASF. Differential expression in three miRNA and corresponding targets (hsa-miR-31-5p:WASF3, hsa-miR-132-3p:RB1, hsa-miR-29c-3p:COL1A1) were also validated. The interactions of these three miRNA–target genes were experimentally validated with past literature. Our transcriptomic and miRNA interactomic investigation identified gene signatures associated with RASF and revealed the involvement of transcription factors and miRNA in an altered transcriptome. These findings help facilitate our understanding of RA with the hope of serving as a springboard for further discoveries relating to the disease.

Medical Use of Cannabinoids

Cannabinoid receptors, endocannabinoids and the enzymes responsible for their biosynthesis and degradation constitute the endocannabinoid system. In recent decades, the endocannabinoid system has attracted considerable interest as a potential therapeutic target in numerous pathological conditions. Its involvement in several physiological processes is well known, such as in energy balance, appetite stimulation, blood pressure, pain modulation, embryogenesis, nausea and vomiting control, memory, learning and immune response, among others, as well as in pathological conditions where it exerts a protective role in the development of certain disorders. As a result, it has been reported that changes in endocannabinoid levels may be related to neurological diseases such as Parkinson's disease, Huntington's disease, Alzheimer's disease and multiple sclerosis, as well as anorexia and irritable bowel syndrome. Alterations in the endocannabinoid system have also been associated with cancer, affecting the growth, migration and invasion of some tumours. Cannabinoids have been tested in several cancer types, including brain, breast and prostate cancers. Cannabinoids have shown promise as analgesics for the treatment of both inflammatory and neuropathic pain. There is also evidence for a role of the endocannabinoid system in the control of emotional states, and cannabinoids could prove useful in decreasing and palliating post-traumatic stress disorder symptoms and anxiolytic disorders. The role of the endocannabinoid system in addictions has also been examined, and cannabinoids have been postulated as alternative and co-adjuvant treatments in some abuse syndromes, mainly in ethanol and opioid abuses. The expression of the endocannabinoid system in the eye suggests that it could be a potential therapeutic target for eye diseases. Considering the importance of the endocannabinoid system and the therapeutic potential of cannabinoids in this vast number of medical conditions, several clinical studies with cannabinoid-based medications are ongoing. In addition, some cannabinoid-based medications have already been approved in various countries, including nabilone and dronabinol capsules for the treatment of nausea and vomiting associated with chemotherapy, dronabinol capsules for anorexia, an oral solution of dronabinol for both vomiting associated with chemotherapy and anorexia, a Δ⁹-tetrahydrocannabinol/cannabidiol oromucosal spray for pain related to cancer and for spasticity and pain associated with multiple sclerosis, and an oral solution of cannabidiol for Dravet and Lennox-Gastaut syndromes. Here, we review the available efficacy, safety and tolerability data for cannabinoids in a range of medical conditions.

Medicinal Properties of Cannabinoids, Terpenes, and Flavonoids in Cannabis, and Benefits in Migraine, Headache, and Pain: An Update on Current Evidence and Cannabis Science

BACKGROUND

Comprehensive literature reviews of historical perspectives and evidence supporting cannabis/cannabinoids in the treatment of pain, including migraine and headache, with associated neurobiological mechanisms of pain modulation have been well described. Most of the existing literature reports on the cannabinoids Δ⁹ -tetrahydrocannabinol (THC) and cannabidiol (CBD), or cannabis in general. There are many cannabis strains that vary widely in the composition of cannabinoids, terpenes, flavonoids, and other compounds. These components work synergistically to produce wide variations in benefits, side effects, and strain characteristics. Knowledge of the individual medicinal properties of the cannabinoids, terpenes, and flavonoids is necessary to cross-breed strains to obtain optimal standardized synergistic compositions. This will enable targeting individual symptoms and/or diseases, including migraine, headache, and pain.

OBJECTIVE

Review the medical literature for the use of cannabis/cannabinoids in the treatment of migraine, headache, facial pain, and other chronic pain syndromes, and for supporting evidence of a potential role in combatting the opioid epidemic. Review the medical literature involving major and minor cannabinoids, primary and secondary terpenes, and flavonoids that underlie the synergistic entourage effects of cannabis. Summarize the individual medicinal benefits of these substances, including analgesic and anti-inflammatory properties.

CONCLUSION

There is accumulating evidence for various therapeutic benefits of cannabis/cannabinoids, especially in the treatment of pain, which may also apply to the treatment of migraine and headache. There is also supporting evidence that cannabis may assist in opioid detoxification and weaning, thus making it a potential weapon in battling the opioid epidemic. Cannabis science is a rapidly evolving medical sector and industry with increasingly regulated production standards. Further research is anticipated to optimize breeding of strain-specific synergistic ratios of cannabinoids, terpenes, and other phytochemicals for predictable user effects, characteristics, and improved symptom and disease-targeted therapies.

Inhibitory role of Gi-coupled receptors on cAMP-driven cancers with focus on opioid receptors in lung adenocarcinoma and its stem cells

The development, progression, metastasis and drug resistance of the most common human cancers are driven by cyclic adenosine monophosphate (cAMP)-signaling downstream of beta-adrenergic receptors (β-Ars) coupled to the stimulatory G-protein G_s. Receptors coupled to the inhibitory G-protein G_i inhibit this signaling cascade by blocking the activation of the enzyme adenylyl cyclase that catalyzes the formation of cAMP and function as the physiological inhibitors of this signaling cascade. Members of the G_i-coupled receptor family widely expressed in the mammalian organism are GABA B receptors (GABA_B-Rs) for the inhibitory neurotransmitter γ-aminobutyric acid (GABA), opioid receptors for endogenous opioid peptides and cannabinoid receptors for endogenous cannabinoids. This review summarizes current evidence for the concept that the activation of G_i-receptor signaling by pharmacological and psychological means is a promising tool for the long-term management of cAMP-driven cancers with special emphasis on the inhibitory effects of opioids on lung adenocarcinoma and its stem cells.

Modulation of the Endocannabinoid System as a Potential Anticancer Strategy

Currently, the involvement of the endocannabinoid system in cancer development and possible options for a cancer-regressive effect of cannabinoids are controversially discussed. In recent decades, a number of preclinical studies have shown that cannabinoids have an anticarcinogenic potential. Therefore, especially against the background of several legal simplifications with regard to the clinical application of cannabinoid-based drugs, an extended basic knowledge about the complex network of the individual components of the endocannabinoid system is required. The canonical endocannabinoid system consists of the endocannabinoids N-arachidonoylethanolamine (anandamide) and 2-arachidonoylglycerol as well as the G_i/o protein-coupled transmembrane cannabinoid receptors CB₁ and CB₂. As a result of extensive studies on the broader effect of these factors, other fatty acid derivatives, transmembrane and intracellular receptors, enzymes and lipid transporters have been identified that contribute to the effect of endocannabinoids when defined in the broad sense as “extended endocannabinoid system.” Among these additional components, the endocannabinoid-degrading enzymes fatty acid amide hydrolase and monoacylglycerol lipase, lipid transport proteins of the fatty acid-binding protein family, additional cannabinoid-activated G protein-coupled receptors such as GPR55, members of the transient receptor family, and peroxisome proliferator-activated receptors were identified as targets for possible strategies to combat cancer progression. Other endocannabinoid-related fatty acids such as 2-arachidonoyl glyceryl ether, O-arachidonoylethanolamine, N-arachidonoyldopamine and oleic acid amide showed an effect via cannabinoid receptors, while other compounds such as endocannabinoid-like substances exert a permissive action on endocannabinoid effects and act via alternative intracellular target structures. This review gives an overview of the modulation of the extended endocannabinoid system using the example of anticancer cannabinoid effects, which have been described in detail in preclinical studies.

Anti-tumour actions of cannabinoids

The endocannabinoid system has emerged as an important target for the treatment of many diverse diseases. In addition to the well-established palliative effects of cannabinoids in cancer therapy, phytocannabinoids, synthetic cannabinoid compounds and inhibitors of endocannabinoid degradation have attracted attention as possible systemic anticancer drugs. Results emerging from preclinical studies suggest cannabinoids elicit effects at different levels of cancer progression, including inhibition of proliferation, neovascularization, invasion and chemoresistance, induction of apoptosis and autophagy as well as enhancement of tumour immune surveillance. Although the clinical use of cannabinoid receptor ligands is limited by their psychoactivity, non-psychoactive compounds, such as cannabidiol, have gained attention due to preclinically established anticancer properties and a favourable risk-to-benefit profile. Thus, cannabinoids may complement the currently used collection of chemotherapeutic agents, as a broadly diversified option for cancer treatment, while counteracting some of their severe side effects. LINKED ARTICLES: This article is part of a themed section on 8th European Workshop on Cannabinoid Research. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.10/issuetoc.

Lung alveolar tissue destruction and protein citrullination in diesel exhaust-exposed mouse lungs

Humanity faces an increasing impact of air pollution worldwide, including threats to human health. Air pollutants prompt and promote chronic inflammation, tumourigenesis, autoimmune and other destructive processes in the human body. Post-translational modification of proteins, for example citrullination, results from damaging attacks of pollutants, including smoking, air pollution and others, rendering host tissues immunogenic. Citrullinated proteins and citrullinating enzymes, deiminases, are more prevalent in patients with COPD and correlate with ongoing inflammation and oxidative stress. In this study, we installed an in-house-designed diesel exhaust delivery and cannabidiol vaporization system where mice were exposed to relevant, urban traffic-related levels of diesel exhaust for 14 days and assessed integrity of alveolar tissue, gene expression shifts and changes in protein content in the lungs and other tissues of exposed mice. Systemic presence of modified proteins was also tested. The protective effect of phytocannabinoids was investigated as well. Data obtained in our study show subacute effects of diesel exhaust on mouse lung integrity and protein content. Emphysematous changes are documented in exposed mouse lungs. In parallel, increased levels of citrulline were detected in the alveolar lung tissue and peripheral blood of exposed mice. Pre-treatment with vaporized cannabidiol ameliorated some damaging effects. Results reported hereby provide new insights into subacute lung tissue changes that follow diesel exhaust exposure and suggest possible dietary and/or other therapeutic interventions for maintaining lung health and healthy ageing.

The Neuro-Psychological Axis of Smoking-Associated Cancer

This mini-review summarizes current knowledge on similarities and synergism between smoking and psychological stress-induced modulations of growth stimulating and inhibiting regulatory networks in epithelial cells and epithelial cancers with emphasis on cancer stimulating neurotransmitters and their receptors as well as cancer inhibiting γ-aminobutyric acid (GABA) and opioids. Hyperactive cAMP signaling downstream of beta-adrenergic receptors (β-ARs) has been identified as the driving force of most smoking-associated cancers by numerous preclinical studies and psychological stress intensifies these effects while experimental stress reduction inhibits. The integration of cAMP reduction via stress reduction by pharmacological and psychological means such as psychotherapy, relaxation meditation and yoga into any cancer treatment strategy is recommended.

Striking lung cancer response to self-administration of cannabidiol: A case report and literature review

In spite of new drugs, lung cancer is associated with a very poor prognosis. While targeted therapies are improving outcomes, it is not uncommon for many patients to have only a partial response, and relapse during follow-up. Thus, new drugs or re-evaluation of existing therapies used to treat other non-malignant diseases (drug repurposing) are still needed. While this research both in vitro and in vivo is being carried out, it is important to be attentive to patients where the disease responds to treatments not considered standard in clinical practice. We report here a patient with adenocarcinoma of the lung who, after declining chemotherapy and radiotherapy, presented with tumour response following self-administration of cannabidiol, a non-psychoactive compound present in Cannabis sativa. Prior work has shown that cannabidiol may have anti-neoplastic properties and enhance the immune response to cancer. The data presented here indicate that cannabidiol might have led to a striking response in a patient with lung cancer.

Cannabidiol modulates phosphorylated rpS6 signalling in a zebrafish model of Tuberous Sclerosis Complex

Tuberous sclerosis complex (TSC) is a rare disease caused by mutations in the TSC1 or TSC2 genes and is characterized by widespread tumour growth, intractable epilepsy, cognitive deficits and autistic behaviour. CBD has been reported to decrease seizures and inhibit tumour cell progression, therefore we sought to determine the influence of CBD on TSC pathology in zebrafish carrying a nonsense mutation in the tsc2 gene. CBD treatment from 6 to 7 days post-fertilization (dpf) induced significant anxiolytic actions without causing sedation. Furthermore, CBD treatment from 3 dpf had no impact on tsc2^-/- larvae motility nor their survival. CBD treatment did, however, reduce the number of phosphorylated rpS6 positive cells, and their cross-sectional cell size. This suggests a CBD mediated suppression of mechanistic target of rapamycin (mTOR) activity in the tsc2^-/- larval brain. Taken together, these data suggest that CBD selectively modulates levels of phosphorylated rpS6 in the brain and additionally provides an anxiolytic effect. This is pertinent given the alterations in mTOR signalling in experimental models of TSC. Additional work is necessary to identify upstream signal modulation and to further justify the use of CBD as a possible therapeutic strategy to manage TSC.

Up-regulation of heme oxygenase-1 expression and inhibition of disease-associated features by cannabidiol in vascular smooth muscle cells

Aberrant proliferation and migration of vascular smooth muscle cells (VSMC) have been closely linked to the development and progression of cardiovascular and cancer diseases. The cytoprotective enzyme heme oxygenase-1 (HO-1) has been shown to mediate anti-proliferative and anti-migratory effects in VSMC. This study investigates the effect of cannabidiol (CBD), a non-psychoactive cannabinoid, on HO-1 expression and disease-associated functions of human umbilical artery smooth muscle cells (HUASMC). HO-1 protein and mRNA were significantly increased by CBD in a time- and concentration-dependent manner. Although the expression of several cannabinoid-activated receptors (CB₁, CB₂, G protein-coupled receptor 55, transient receptor potential vanilloid 1) was verified in HUASMC, CBD was shown to induce HO-1 via none of these targets. Instead, the CBD-mediated increase in HO-1 protein was reversed by the glutathione precursor N-acetylcysteine, indicating the participation of reactive oxygen species (ROS) signaling; this was confirmed by flow cytometry-based ROS detection. CBD-induced HO-1 expression was accompanied by inhibition of growth factor-mediated proliferation and migration of HUASMC. However, neither inhibition of HO-1 activity nor knockdown of HO-1 protein attenuated CBD-mediated anti-proliferative and anti-migratory effects. Indeed, inhibition or depletion of HO-1 resulted in induction of apoptosis and intensified CBD-mediated effects on proliferation and migration. Collectively, this work provides the first indication of CBD-mediated enhancement of HO-1 in VSMC and potential protective effects against aberrant VSMC proliferation and migration. On the other hand, our data argue against a role of HO-1 in CBD-mediated inhibition of proliferation and migration while substantiating its anti-apoptotic role in oxidative stress-mediated cell fate.

Cannabidiol (CBD) Is a Novel Inhibitor for Exosome and Microvesicle (EMV) Release in Cancer

Exosomes and microvesicles (EMV) are lipid bilayer-enclosed structures, released by cells and involved in intercellular communication through transfer of proteins and genetic material. EMV release is also associated with various pathologies, including cancer, where increased EMV release is amongst other associated with chemo-resistance and active transfer of pro-oncogenic factors. Recent studies show that EMV-inhibiting agents can sensitize cancer cells to chemotherapeutic agents and reduce cancer growth in vivo. Cannabidiol (CBD), a phytocannabinoid derived from Cannabis sativa, has anti-inflammatory and anti-oxidant properties, and displays anti-proliferative activity. Here we report a novel role for CBD as a potent inhibitor of EMV release from three cancer cell lines: prostate cancer (PC3), hepatocellular carcinoma (HEPG2) and breast adenocarcinoma (MDA-MB-231). CBD significantly reduced exosome release in all three cancer cell lines, and also significantly, albeit more variably, inhibited microvesicle release. The EMV modulating effects of CBD were found to be dose dependent (1 and 5 μM) and cancer cell type specific. Moreover, we provide evidence that this may be associated with changes in mitochondrial function, including modulation of STAT3 and prohibitin expression, and that CBD can be used to sensitize cancer cells to chemotherapy. We suggest that the known anti-cancer effects of CBD may partly be due to the regulatory effects on EMV biogenesis, and thus CBD poses as a novel and safe modulator of EMV-mediated pathological events.

Involvement of the CB2 cannabinoid receptor in cell growth inhibition and G0/G1 cell cycle arrest via the cannabinoid agonist WIN 55,212-2 in renal cell carcinoma

BACKGROUND

The anti-tumor properties of cannabinoids have been investigated in many in vitro and in vivo studies. Many of these anti-tumor effects are mediated via cannabinoid receptor types 1 and 2 (CB₁ and CB₂), comprising the endocannabinoid system (ECS). In this study, we investigated the ECS based on CB ₁ and CB ₂ receptor gene and protein expression in renal cell carcinoma (RCC) cell lines. In view of their further use for potential treatments, we thus investigated the roles of CB₁ and CB₂ receptors in the anti-proliferative action and signal transduction triggered by synthetic cannabinoid agonists [such as JWH-133 and WIN 55,212-2 (WIN-55)] in RCC cell lines.

METHODS

Human RCC cell lines were used for this study. The CB ₁ and CB ₂ gene expression levels were analyzed using real-time PCR. Flow cytometric, immunocytochemical and western blot analyses were performed to confirm CB₁ and CB₂ receptor protein expression. The anti-proliferative effects of synthetic cannabinoids were investigated on cell viability assay. The CB₁ and CB₂ receptors were blocked pharmacologically with the antagonists SR141716A and AM-630, respectively, to investigate the effects of the agonists JWH-133 and WIN-55. Cell cycle, apoptosis and LDH-based cytotoxicity were analyzed on cannabinoid-treated RCC cells.

RESULTS

The CB1 and CB2 genes expression was shown by real-time PCR and flow cytometric and western blot analysis indicating a higher level of CB₂ receptor as compared to CB₁ in RCC cells. Immunocytochemical staining also confirmed the expression of the CB₁ and CB₂ proteins. We also found that the synthetic cannabinoid agonist WIN-55 exerted anti-proliferative and cytotoxic effects by inhibiting the growth of RCC cell lines, while the CB₂ agonist JWH-133 did not. Pharmacologically blocking the CB1 and CB2 receptors with their respective antagonists SR141716A and AM-630, followed by the WIN-55 treatment of RCC cells allowed uncovering the involvement of CB2, which led to an arrest in the G0/G1 phase of the cell cycle and apoptosis.

CONCLUSIONS

This study elucidated the involvement of CB₂ in the in vitro inhibition of RCC cells, and future applications of CB₂ agonists in the prevention and management of RCC are discussed.

The current state and future perspectives of cannabinoids in cancer biology

To date, cannabinoids have been allowed in the palliative medicine due to their analgesic and antiemetic effects, but increasing number of preclinical studies indicates their anticancer properties. Cannabinoids exhibit their action by a modulation of the signaling pathways crucial in the control of cell proliferation and survival. Many in vitro and in vivo experiments have shown that cannabinoids inhibit proliferation of cancer cells, stimulate autophagy and apoptosis, and have also a potential to inhibit angiogenesis and metastasis. In this review, we present an actual state of knowledge regarding molecular mechanisms of cannabinoids' anticancer action, but we discuss also aspects that are still not fully understood such as the role of the endocannabinoid system in a carcinogenesis, the impact of cannabinoids on the immune system in the context of cancer development, or the cases of a stimulation of cancer cells' proliferation by cannabinoids. The review includes also a summary of currently ongoing clinical trials evaluating the safety and efficacy of cannabinoids as anticancer agents.

Fatty acid amide hydrolase inhibitors confer anti-invasive and antimetastatic effects on lung cancer cells

Inhibition of endocannabinoid degradation has been suggested as tool for activation of endogenous tumor defense. One of these strategies lies in blockade of fatty acid amide hydrolase (FAAH) which catalyzes the degradation of endocannabinoids (anandamide [AEA], 2-arachidonoylglycerol [2-AG]) and endocannabinoid-like substances (N-oleoylethanolamine [OEA], N-palmitoylethanolamine [PEA]). This study addressed the impact of two FAAH inhibitors (arachidonoyl serotonin [AA-5HT], URB597) on A549 lung cancer cell metastasis and invasion. LC-MS analyses revealed increased levels of FAAH substrates (AEA, 2-AG, OEA, PEA) in cells incubated with either FAAH inhibitor. In athymic nude mice FAAH inhibitors were shown to elicit a dose-dependent antimetastatic action yielding a 67% and 62% inhibition of metastatic lung nodules following repeated administration of 15 mg/kg AA-5HT and 5 mg/kg URB597, respectively. In vitro, a concentration-dependent anti-invasive action of either FAAH inhibitor was demonstrated, accompanied with upregulation of tissue inhibitor of matrix metalloproteinases-1 (TIMP-1). Using siRNA approaches, a causal link between the TIMP-1-upregulating and anti-invasive action of FAAH inhibitors was confirmed. Moreover, knockdown of FAAH by siRNA was shown to confer decreased cancer cell invasiveness and increased TIMP-1 expression. Inhibitor experiments point toward a role of CB₂ and transient receptor potential vanilloid 1 in conferring anti-invasive effects of FAAH inhibitors and FAAH siRNA. Finally, antimetastatic and anti-invasive effects were confirmed for all FAAH substrates with AEA and OEA causing a TIMP-1-dependent anti-invasive action. Collectively, the present study provides first-time proof for an antimetastatic action of FAAH inhibitors. As mechanism of its anti-invasive properties an upregulation of TIMP-1 was identified.

Standardized Cannabis sativa extract attenuates tau and stathmin gene expression in the melanoma cell line

Objective(s):

Metastasis is the main cause of death in patients with melanoma. Cannabis-based medicines are effective adjunctive drugs in cancer patients. Tau and Stathmin proteins are the key proteins in cancer metastasis. Here we have investigated the effect of a standardized Cannabis sativa extract on cell migration and Tau and Stathmin gene expression in the melanoma cell line.

Materials and Methods:

In the treatment group, melanoma (B1617) was treated 48 hr with various concentrations of standardized C. sativa extract. Cells with no treatment were considered as the control group, then study was followed by Quantitative RT-Real Time PCR assay. Relative gene expression was calculated by the ΔΔct method. Migration assay was used to evaluate cancer metastasis.

Results:

Tau and stathmin gene expression was significantly decreased compared to the control group. Cell migration was also significantly reduced compared to controls.

Conclusion:

C. sativa decreased tau and stathmin gene expression and cancer metastasis. The results may have some clinical relevance for the use of cannabis-based medicines in patients with metastatic melanoma.

Role of LFA-1 and ICAM-1 in Cancer

The lymphocyte function-associated antigen-1 (LFA-1) (also known as CD11a/CD18 and α_Lβ₂), is just one of many integrins in the human body, but its significance is derived from its exclusive presence in leukocytes. In this review, we summarize the studies relating LFA-1 and its major ligand ICAM-1 (or CD54) with cancer, through the function of lymphocytes and myeloid cells on tumor cells. We consider how LFA-1 mediates the interaction of leukocytes with tumors and the role of ICAM-1 in tumor dynamics, which can be independent of its interaction with LFA-1. We also offer a more detailed examination of the role of LFA-1 within B-cell chronic lymphocytic leukemia. Finally, we discuss the role that exosomes harboring LFA-1 play in tumor growth and metastasis.

Bufalin attenuates cancer-induced pain and bone destruction in a model of bone cancer

Bufalin is a natural anti-inflammatory small molecule. Given the close relationship between inflammation and cancer, many scholars have studied the effect of bufalin on cancer in vitro, but in vivo research is still lacking. A murine bone cancer model was used in this study. We conducted pain sensitive test on mice with bone cancer, by nocifensive behavior, mechanical allodynia, and thermal hyperalgesia. Serum levels of bone loss markers with bufalin treatment were measured by ELISA. Expressions of osteoprotegerin (OPG) and receptor activator of NF-κB ligand (RANKL) were analyzed in bufalin-treated mice by real-time PCR and Western blot. Cannabinoid 2 receptor (CB2) inverse agonist AM630 was administrated to mice with bone cancer together with bufalin. Bufalin relieved cancer-induced pain and bone destruction in the murine bone cancer model. Serum levels of bone loss markers after bufalin treatment were reduced. Bufalin upregulated OPG and downregulated RANKL. The CB2 receptor inverse agonist, AM630, reduced the pain relief of bufalin treatment in the mouse bone cancer model. This study demonstrates that bufalin relieves cancer-induced pain and bone destruction, which is mediated through the CB2 receptor.

4,5-Di-O-Caffeoylquinic Acid from Ligularia fischeri Suppresses Inflammatory Responses Through TRPV1 Activation

Ligularia fischeri (Ledeb.) Turcz., a perennial plant native to northeastern Asia, has long been used as folk remedies for the alleviation of inflammatory symptoms. We investigated whether the extract of L. fischeri (LFEx) and caffeoylquinic acid (CQA) derivatives, the pharmacologically active ingredients identified from L. fischeri, regulate inflammation via a transient receptor potential vanilloid 1 (TRPV1)-mediated pathway. Changes in intracellular Ca²⁺ levels to the LFEx and trans-5-O-CQA, 3,4-di-O-CQA, 3,5-di-O-CQA, and 4,5-di-O-CQA were monitored in TRPV1-expressing human embryonic kidney cell HEK 293T. LFEx and 4,5-di-O-CQA (EC₅₀  = 69.34 ± 1.12 μM) activated TRPV1, and these activations were significantly inhibited by ruthenium red, a general blocker of TRP channels, and capsazepine, a specific antagonist of TRPV1. 4,5-Di-O-CQA has been determined having antiinflammatory effect under hypoxic conditions by detecting the expression of cyclooxygenase-2 (COX-2), a representative inflammatory marker, and cellular migration in human pulmonary epithelial A549 cells. 4,5-Di-O-CQA suppressed COX-2 expression and cell migration, and this inhibition was countered by co-treatment with capsazepine. This study provides evidence that L. fischeri is selective to inflammatory responses via a TRPV1-mediated pathway, and 4,5-di-O-CQA might play a key role to create these effects. Copyright © 2017 John Wiley & Sons, Ltd.

Cannabinoids as Anticancer Drugs

The endocannabinoid system encompassing cannabinoid receptors, endogenous receptor ligands (endocannabinoids), as well as enzymes conferring the synthesis and degradation of endocannabinoids has emerged as a considerable target for pharmacotherapeutical approaches of numerous diseases. Besides palliative effects of cannabinoids used in cancer treatment, phytocannabinoids, synthetic agonists, as well as substances that increase endogenous endocannabinoid levels have gained interest as potential agents for systemic cancer treatment. Accordingly, cannabinoid compounds have been reported to inhibit tumor growth and spreading in numerous rodent models. The underlying mechanisms include induction of apoptosis, autophagy, and cell cycle arrest in tumor cells as well as inhibition of tumor cell invasion and angiogenic features of endothelial cells. In addition, cannabinoids have been shown to suppress epithelial-to-mesenchymal transition, to enhance tumor immune surveillance, and to support chemotherapeutics' effects on drug-resistant cancer cells. However, unwanted side effects include psychoactivity and possibly pathogenic effects on liver health. Other cannabinoids such as the nonpsychoactive cannabidiol exert a comparatively good safety profile while exhibiting considerable anticancer properties. So far experience with anticarcinogenic effects of cannabinoids is confined to in vitro studies and animal models. Although a bench-to-bedside conversion remains to be established, the current knowledge suggests cannabinoid compounds to serve as a group of drugs that may offer significant advantages for patients suffering from cancer diseases. The present review summarizes the role of the endocannabinoid system and cannabinoid compounds in tumor progression.

An Update on Safety and Side Effects of Cannabidiol: A Review of Clinical Data and Relevant Animal Studies

Introduction: This literature survey aims to extend the comprehensive survey performed by Bergamaschi et al. in 2011 on cannabidiol (CBD) safety and side effects. Apart from updating the literature, this article focuses on clinical studies and CBD potential interactions with other drugs. Results: In general, the often described favorable safety profile of CBD in humans was confirmed and extended by the reviewed research. The majority of studies were performed for treatment of epilepsy and psychotic disorders. Here, the most commonly reported side effects were tiredness, diarrhea, and changes of appetite/weight. In comparison with other drugs, used for the treatment of these medical conditions, CBD has a better side effect profile. This could improve patients' compliance and adherence to treatment. CBD is often used as adjunct therapy. Therefore, more clinical research is warranted on CBD action on hepatic enzymes, drug transporters, and interactions with other drugs and to see if this mainly leads to positive or negative effects, for example, reducing the needed clobazam doses in epilepsy and therefore clobazam's side effects. Conclusion: This review also illustrates that some important toxicological parameters are yet to be studied, for example, if CBD has an effect on hormones. Additionally, more clinical trials with a greater number of participants and longer chronic CBD administration are still lacking.

Cannabidiol: State of the art and new challenges for therapeutic applications

Over the past years, several lines of evidence support a therapeutic potential of Cannabis derivatives and in particular phytocannabinoids. Δ⁹-THC and cannabidiol (CBD) are the most abundant phytocannabinoids in Cannabis plants and therapeutic application for both compounds have been suggested. However, CBD is recently emerging as a therapeutic agent in numerous pathological conditions since devoid of the psychoactive side effects exhibited instead by Δ⁹-THC. In this review, we highlight the pharmacological activities of CBD, its cannabinoid receptor-dependent and -independent action, its biological effects focusing on immunomodulation, angiogenetic properties, and modulation of neuronal and cardiovascular function. Furthermore, the therapeutic potential of cannabidiol is also highlighted, in particular in nuerological diseases and cancer.

Targeting calcium signaling in cancer therapy

The intracellular calcium ions (Ca2+) act as second messenger to regulate gene transcription, cell proliferation, migration and death. Accumulating evidences have demonstrated that intracellular Ca2+ homeostasis is altered in cancer cells and the alteration is involved in tumor initiation, angiogenesis, progression and metastasis. Targeting derailed Ca2+ signaling for cancer therapy has become an emerging research area. This review summarizes some important Ca2+ channels, transporters and Ca2+-ATPases, which have been reported to be altered in human cancer patients. It discusses the current research effort toward evaluation of the blockers, inhibitors or regulators for Ca2+ channels/transporters or Ca2+-ATPase pumps as anti-cancer drugs. This review is also aimed to stimulate interest in, and support for research into the understanding of cellular mechanisms underlying the regulation of Ca2+ signaling in different cancer cells, and to search for novel therapies to cure these malignancies by targeting Ca2+ channels or transporters.

The Therapeutic Aspects of the Endocannabinoid System (ECS) for Cancer and their Development: From Nature to Laboratory

The endocannabinoid system (ECS) is a group of neuromodulatory lipids and their receptors, which are widely distributed in mammalian tissues. ECS regulates various cardiovascular, nervous, and immune system functions inside cells. In recent years, there has been a growing body of evidence for the use of synthetic and natural cannabinoids as potential anticancer agents. For instance, the CB1 and CB2 receptors are assumed to play an important role inside the endocannabinoid system. These receptors are abundantly expressed in the brain and fatty tissue of the human body. Despite recent developments in molecular biology, there is still a lack of knowledge about the distribution of CB1 and CB2 receptors in the human kidney and their role in kidney cancer. To address this gap, we explore and demonstrate the role of the endocannabinoid system in renal cell carcinoma (RCC). In this brief overview, we elucidate the therapeutic aspects of the endocannabinoid system for various cancers and explain how this system can be used for treating kidney cancer. Overall, this review provides new insights into cannabinoids' mechanisms of action in both in vivo and in vitro models, and focuses on recent discoveries in the field.

Celecoxib increases lung cancer cell lysis by lymphokine-activated killer cells via upregulation of ICAM-1

The antitumorigenic mechanism of the selective cyclooxygenase-2 (COX-2) inhibitor celecoxib is still a matter of debate. Using lung cancer cell lines (A549, H460) and metastatic cells derived from a lung cancer patient, the present study investigates the impact of celecoxib on the expression of intercellular adhesion molecule 1 (ICAM-1) and cancer cell lysis by lymphokine-activated killer (LAK) cells. Celecoxib, but not other structurally related selective COX-2 inhibitors (i.e., etoricoxib, rofecoxib, valdecoxib), was found to cause a substantial upregulation of ICAM-1 protein levels. Likewise, ICAM-1 mRNA expression was increased by celecoxib. Celecoxib enhanced the susceptibility of cancer cells to be lysed by LAK cells with the respective effect being reversed by a neutralizing ICAM-1 antibody. In addition, enhanced killing of celecoxib-treated cancer cells was reversed by preincubation of LAK cells with an antibody to lymphocyte function associated antigen 1 (LFA-1), suggesting intercellular ICAM-1/LFA-1 crosslink as crucial event within this process. Finally, celecoxib elicited no significant increase of LAK cell-mediated lysis of non-tumor bronchial epithelial cells, BEAS-2B, associated with a far less ICAM-1 induction as compared to cancer cells. Altogether, our data demonstrate celecoxib-induced upregulation of ICAM-1 on lung cancer cells to be responsible for intercellular ICAM-1/LFA-1 crosslink that confers increased cancer cell lysis by LAK cells. These findings provide proof for a novel antitumorigenic mechanism of celecoxib.

Targeting the Endocannabinoid System in Psychiatric Illness

Prevalence of psychiatric disorders continues to rise globally, yet remission rates and patient outcome remain less than ideal. As a result, novel treatment approaches for these disorders are necessary to decrease societal economic burden, as well as increase individual functioning. The recent discovery of the endocannabinoid system has provided an outlet for further research into its role in psychiatric disorders, because efficacy of targeted treatments have been demonstrated in medical illnesses, including cancers, neuropathic pain, and multiple sclerosis. The present review will investigate the role of the endocannabinoid system in psychiatric disorders, specifically schizophrenia, depressive, anxiety, and posttraumatic stress disorders, as well as attention-deficit hyperactivity disorder. Controversy remains in prescribing medicinal cannabinoid treatments due to the fear of adverse effects. However, one must consider all potential limitations when determining the safety and tolerability of cannabinoid products, specifically cannabinoid content (ie, Δ-tetrahydrocannabinol vs cannabidiol) as well as study design. The potential efficacy of cannabinoid treatments in the psychiatric population is an emerging topic of interest that provides potential value going forward in medicine.

Preclinical and Clinical Assessment of Cannabinoids as Anti-Cancer Agents

Cancer is the second leading cause of death in the United States with 1.7 million new cases estimated to be diagnosed in 2016. This disease remains a formidable clinical challenge and represents a substantial financial burden to the US health care system. Therefore, research and development of novel therapeutics for the treatment of cancer is of high priority. Cannabinoids and their derivatives have been utilized for their medicinal and therapeutic properties throughout history. Cannabinoid activity is regulated by the endocannabinoid system (ECS), which is comprised of cannabinoid receptors, transporters, and enzymes involved in cannabinoid synthesis and breakdown. More recently, cannabinoids have gained special attention for their role in cancer cell proliferation and death. However, many studies investigated these effects using in vitro models which may not adequately mimic tumor growth and metastasis. As such, this article aims to review study results which evaluated effects of cannabinoids from plant, synthetic and endogenous origins on cancer development in preclinical animal models and to examine the current standing of cannabinoids that are being tested in human cancer patients.

Lipid mediators involved in the oxidative stress and antioxidant defence of human lung cancer cells

Background

The oxidative modifications of bioactive macromolecules have important roles in carcinogenesis. Of particular interest are lipid peroxidation products, which are involved in the activation of Nrf2 and endocannabinoids that affect cancer progression.

Methods

In lung cancer tissues (squamous cell lung carcinoma - SCC and adenocarcinoma - AC), the glutathione peroxidase and catalase activity and glutathione level, together with the expression of Nrf2 and its activators/inhibitors were estimated. The oxidative modifications of DNA (8-hydroxy-2′-deoxyguanosine and N7-methylguanine), endocannabinoids (anandamide and 2- arachidonylglyceriol), their receptors (CB1/2, TRV1, GPR55), phospholipid fatty acids (arachidonic, linoleic and docosahexaenoic), and reactive aldehydes (4-hydroxynonenal, 4-oxononenal and malondialdehyde) were determined.

Results

Tumour tissues showed lower antioxidant capacity than healthy tissues, which was accompanied by lower levels of fatty acids and higher levels of reactive aldehydes. Disturbances in antioxidant capacity and enhanced DNA oxidative modifications were observed in 88% of AC patients and 81% of SCC patients. The 4-hydroxynonenal-Histidine adducts were detected in the necrotic and stromal cells in all tumours. These findings were associated with the enhanced Nrf2 activity, especially in AC. The strong difference between the cancer subtypes was evident in the levels of endocannabinoids, with an increase in 89% of SCC and a decrease in 85% of AC patients being observed. Additionally, the increase in the expression of CB1/2 receptors was observed only in 82% of AC, while the expression of VR1 and GPR55 was enhanced in 79% of SCC and 82% of AC patients.

Conclusions

This study shows significant differences in the redox status, Nrf2 pathway and endocannabinoid system between SCC and AC tissues. Understanding the relation between the various lipid mediators and antioxidants in different lung cancer subtypes may be beginning for further research on the effective anticancer therapy.

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AC tissues show lower antioxidant capacity than SCC.

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Nrf2/ARE pathway is activated stronger in AC than in SCC.

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AC exhibits more lipid oxidative modifications than SCC.

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HNE-protein adducts are detected in the necrotic and stromal cells in SCC and AC.

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SCC exhibits increase in endocannabinoids level while in AC reverse effect is observed.

Endocannabinoid system as a regulator of tumor cell malignancy - biological pathways and clinical significance

The endocannabinoid system (ECS) comprises cannabinoid receptors (CBs), endogenous cannabinoids, and enzymes responsible for their synthesis, transport, and degradation of (endo)cannabinoids. To date, two CBs, CB1 and CB2, have been characterized; however, orphan G-protein-coupled receptor GPR55 has been suggested to be the third putative CB. Several different types of cancer present abnormal expression of CBs, as well as other components of ECS, and this has been shown to correlate with the clinical outcome. Although most effects of (endo)cannabinoids are mediated through stimulation of classical CBs, they also interact with several molecules, either prosurvival or proapoptotic molecules. It should be noted that the mode of action of exogenous cannabinoids differs significantly from that of endocannabinoid and results from the studies on their activity both in vivo and in vitro could not be easily compared. This review highlights the main signaling pathways involved in the antitumor activity of cannabinoids and the influence of their activation on cancer cell biology. We also discuss changes in the expression pattern of the ECS in various cancer types that have an impact on disease progression and patient survival. A growing amount of experimental data imply possible exploitation of cannabinoids in cancer therapy.

2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside suppresses human colorectal cancer cell metastasis through inhibiting NF-κB activation

2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside (THSG), a major component of Polygonum multiflorum Thunb (He-Shou-Wu), has been reported to exhibit antioxidant and anti-inflammatory effects. However, its anti-metastatic effect against colorectal cancer is still unclear. In this study, cell migration, invasion and adhesion abilities as well as metastasis-associated protein and NF-κB pathway signaling factor expression were analyzed after treating HT-29 cells with THSG. According to the results, the migration and invasiveness of HT-29 cells were reduced after treatment with 5 or 10 mM THSG (p<0.05). Additionally, the levels of matrix metalloproteinase-2 (MMP-2) and phosphorylated VE-cadherin in HT-29 cells were reduced and the transepithelial electrical resistance (TEER) of EA.hy926 endothelial cell monolayers was increased after incubation in THSG for 24 h (p<0.05). Cell adhesion ability and the E-selectin and intercellular adhesion molecule-1 (ICAM-1) protein levels were reduced when EA.hy926 endothelial cells were treated with THSG (p<0.05). In addition, the cytoplasmic phosphorylation of IκB, the nuclear p65 level and the DNA-binding activity of NF-κB were reduced after treating HT-29 or EA.hy926 cells with 5 or 10 mM THSG (p<0.05). These results suggest that THSG inhibits HT-29 cell metastasis by suppressing cell migration, invasion and adhesion. Furthermore, THSG inhibits metastasis-associated protein expression by suppressing NF-κB pathway activation.

Antitumorigenic targets of cannabinoids - current status and implications

INTRODUCTION

Molecular structures of the endocannabinoid system have gained interest as potential pharmacotherapeutical targets for systemic cancer treatment.

AREAS COVERED

The present review covers the contribution of the endocannabinoid system to cancer progression. Particular focus will be set on the accumulating preclinical data concerning antimetastatic, anti-invasive and anti-angiogenic mechanisms induced by cannabinoids.

EXPERT OPINION

The main goal of targeting endocannabinoid structures for systemic anticancer treatment is the comparatively good safety profile of cannabinoid compounds. In addition, antitumorigenic mechanisms of cannabinoids are not restricted to a single molecular cascade but involve multiple effects on various levels of cancer progression such as angiogenesis and metastasis. Particularly the latter effect has gained interest for pharmacological interventions. Thus, drugs aiming at the endocannabinoid system may represent potential 'antimetastatics' for an upgrade of a future armamentarium against cancer diseases.

Downregulation of human intercellular adhesion molecule-1 attenuates the metastatic ability in human breast cancer cell lines

Intercellular adhesion molecule-1 (ICAM-1) is a cell surface glycoprotein that belongs to immunoglobulin superfamily and plays an important role in tumor cell expansion or metastasis. However, the detailed mechanisms of ICAM-1 in breast cancer remain unclear. In this study, we evaluated the expression level of ICAM-1 in breast cancer using tissue microarray and clinical tissue specimens by immunohistochemical method, and the results revealed that ICAM-1 is highly expressed in the breast cancer tissues. To investigate whether ICAM-1 can affect the metastasis ability in breast cancer, we knocked down ICAM-1 expression in breast cancer cell line MCF-7 by using lentivirus-mediated RNA interference (RNAi). As a result, we stably silenced ICAM-1 expression in MCF-7 cells by infection with lentivirus expressing green fluorescent protein (GFP), the change of metastatic ability of MCF-7 cells was assessed by wound-healing assay, Transwell assay or clone formation assay. Our results showed that silencing of ICAM-1 can inhibit the metastatic ability of MCF-7 cell lines in vitro significantly, and the decreased migration and invasion was accompanied by a reduction of MMP-14. These results implying that ICAM-1 might be involved in the progression of breast cancer metastasis and lentivirus-mediated silencing of ICAM-1 might be a potential therapeutic approach for the treatment of breast cancer.

GPR55 promotes migration and adhesion of colon cancer cells indicating a role in metastasis

BACKGROUND AND PURPOSE

Tumour cell migration and adhesion constitute essential features of metastasis. G-protein coupled receptor 55 (GPR55), a lysophospholipid receptor, has been shown to play an important role in carcinogenesis. Here, we investigated the involvement of GPR55 in migration and metastasis of colon cancer cells.

EXPERIMENTAL APPROACH

Adhesion and migration assays using the highly metastatic colon cancer cell line HCT116 and an in vivo assay of liver metastasis were performed. The GPR55 antagonist CID16020046, cannabidiol, a putative GPR55 antagonist and GPR55 siRNA were used to block GPR55 activity in HCT116 colon cancer cells.

KEY RESULTS

HCT116 cells showed a significant decrease in adhesion to endothelial cells and in migration after blockade with CID16020046 or cannabidiol. The inhibitory effects of CID16020046 or cannabidiol were averted by GPR55 siRNA knock down in cancer cells. The integrity of endothelial cell monolayers was increased after pretreatment of HCT116 cells with the antagonists or after GPR55 siRNA knockdown while pretreatment with lysophosphatidylinositol (LPI), the endogenous ligand of GPR55, decreased integrity of the monolayers. LPI also induced migration in GPR55 overexpressing HCT116 cells that was blocked by GPR55 antagonists. In a mouse model of metastasis, the arrest of HCT116 cancer cells in the liver was reduced after treatment with CID16020046 or cannabidiol. Increased levels of LPI (18:0) were found in colon cancer patients when compared with healthy individuals.

CONCLUSIONS AND IMPLICATIONS

GPR55 is involved in the migratory behaviour of colon carcinoma cells and may serve as a pharmacological target for the prevention of metastasis. © 2015 The British Pharmacological Society.

Cannabinoids as therapeutic agents in cancer: current status and future implications

The pharmacological importance of cannabinoids has been in study for several years. Cannabinoids comprise of (a) the active compounds of the Cannabis sativa plant, (b) endogenous as well as (c) synthetic cannabinoids. Though cannabinoids are clinically used for anti-palliative effects, recent studies open a promising possibility as anti-cancer agents. They have been shown to possess anti-proliferative and anti-angiogenic effects in vitro as well as in vivo in different cancer models. Cannabinoids regulate key cell signaling pathways that are involved in cell survival, invasion, angiogenesis, metastasis, etc. There is more focus on CB1 and CB2, the two cannabinoid receptors which are activated by most of the cannabinoids. In this review article, we will focus on a broad range of cannabinoids, their receptor dependent and receptor independent functional roles against various cancer types with respect to growth, metastasis, energy metabolism, immune environment, stemness and future perspectives in exploring new possible therapeutic opportunities.

Assessing the carcinogenic potential of low-dose exposures to chemical mixtures in the environment: focus on the cancer hallmark of tumor angiogenesis

One of the important 'hallmarks' of cancer is angiogenesis, which is the process of formation of new blood vessels that are necessary for tumor expansion, invasion and metastasis. Under normal physiological conditions, angiogenesis is well balanced and controlled by endogenous proangiogenic factors and antiangiogenic factors. However, factors produced by cancer cells, cancer stem cells and other cell types in the tumor stroma can disrupt the balance so that the tumor microenvironment favors tumor angiogenesis. These factors include vascular endothelial growth factor, endothelial tissue factor and other membrane bound receptors that mediate multiple intracellular signaling pathways that contribute to tumor angiogenesis. Though environmental exposures to certain chemicals have been found to initiate and promote tumor development, the role of these exposures (particularly to low doses of multiple substances), is largely unknown in relation to tumor angiogenesis. This review summarizes the evidence of the role of environmental chemical bioactivity and exposure in tumor angiogenesis and carcinogenesis. We identify a number of ubiquitous (prototypical) chemicals with disruptive potential that may warrant further investigation given their selectivity for high-throughput screening assay targets associated with proangiogenic pathways. We also consider the cross-hallmark relationships of a number of important angiogenic pathway targets with other cancer hallmarks and we make recommendations for future research. Understanding of the role of low-dose exposure of chemicals with disruptive potential could help us refine our approach to cancer risk assessment, and may ultimately aid in preventing cancer by reducing or eliminating exposures to synergistic mixtures of chemicals with carcinogenic potential.

The evolving role of the endocannabinoid system in gynaecological cancer

BACKGROUND

The 'endocannabinoid system' (ECS), comprising endogenous ligands (endocannabinoids) and their regulating enzymes, together with the cannabinoid receptors, has attracted a great deal of attention because it affects not only all facets of human reproduction, from gametogenesis through to parturition and beyond, but also targets key mechanisms affecting some hallmarks of cancer. Recent evidence showing that cannabinoid receptors play a very important role in the development of malignancies outside of the reproductive organs suggests a similar role for the ECS in the establishment or continued development of gynaecological malignancy.

METHODS

Primary papers and review articles, and primary sources within these papers, up to December 2014, on the evolving role of the ECS in cancer, with a special focus on gynaecological cancers, were obtained by Medline and PubMed searches using the search terms: 'cancer', 'cannabinoid', 'endocannabinoid', 'gynaecology' and 'malignancy'. Non-English manuscripts were excluded.

RESULTS

More than 2100 sources were obtained from which only 112 were specifically important to the topic. Analysis of those articles supports a role of the ECS in gynaecological cancers but leaves many gaps in our knowledge that need to be filled. How some of the relevant receptors are activated and cause changes in cell phenotypes that progress to malignancy remains undiscovered and an area for future research. Increasing evidence suggests that malignant transformation within the female genital tract could be accompanied by deregulation of components of the ECS, acting through rather complex cannabinoid receptor-dependent and receptor-independent mechanisms.

CONCLUSIONS

The paucity of studies in this area suggests that research using animal models is needed to evaluate endocannabinoid signalling in cancer networks. Future randomized clinical studies should reveal whether endocannabinoids or their derivatives prove to be useful therapeutic targets for gynaecological and other cancers.

Delta(9) -tetrahydrocannabinol and cannabidiol as potential curative agents for cancer: A critical examination of the preclinical literature

An Internet search with search words "cannabis cures cancer" produce a wealth of sites claiming that cannabis has this effect. These sites are freely accessible to the general public and thus contribute to public opinion. But do delta(9) -tetrahydrocannabinol (Δ(9) -THC) and cannabidiol (CBD) cure cancer? In the absence of clinical data other than a safety study and case reports, preclinical data should be evaluated in terms of its predictive value. Using a strict approach where only concentrations and/or models relevant to the clinical situation are considered, the current preclinical data do not yet provide robust evidence that systemically administered Δ(9) -THC will be useful for the curative treatment of cancer. There is more support for an intratumoral route of administration of higher doses of Δ(9) -THC. CBD produces effects in relevant concentrations and models, although more data are needed concerning its use in conjunction with other treatment strategies.