Should Oncologists Recommend Cannabis?

Selective Cytotoxicity of Medical Cannabis (Cannabis sativa L.) Extracts Across the Whole Vegetation Cycle Under Various Hydroponic and Nutritional Treatments

Introduction: The use of Cannabis sativa L. in health care requires stringent care for the optimal production of the bioactive compounds. However, plant phenotypes and the content of secondary metabolites, such as phytocannabinoids, are strongly influenced by external factors, such as nutrient availability. It has been shown that phytocannabinoids can exhibit selective cytotoxicity against various cancer cell lines while protecting healthy tissue from apoptosis. Research Aim: This study aimed to clarify the cytotoxic effect of cannabis extracts on colorectal cell lines by identifying the main active compounds and determining their abundance and activity across all developmental stages of medical cannabis plants cultivated under hydroponic conditions. Materials and Methods: Dimethyl sulfoxide extracts of medical cannabis plants bearing the genotype classified as chemotype I were analyzed by high-performance liquid chromatography, and their cytotoxic activity was determined by measuring cell viability by methylthiazolyldiphenyl-tetrazolium bromide assay on the human colon cancer cell lines, Caco-2 and HT-29, and the normal human epithelial cell line, CCD 841 CoN. Results: The most abundant phytocannabinoid in cannabis extracts was tetrahydrocannabinolic acid (THCA). Its maximum concentrations were reached from the 7th to the 13th plant vegetation week, depending on the nutritional cycle and treatment. Almost all extracts were cytotoxic to the human colorectal cancer (CRC) cell line HT-29 at lower concentrations than the other cell lines. The phytocannabinoids that most affected the cytotoxicity of individual extracts on HT-29 were cannabigerol, Δ9-tetrahydrocannabinol, cannabidiol, cannabigerolic acid, and THCA. The tested model showed almost 70% influence of these cannabinoids. However, THCA alone influenced the cytotoxicity of individual extracts by nearly 65%. Conclusions: Phytocannabinoid extracts from plants of the THCA-dominant chemotype interacted synergistically and showed selective cytotoxicity against the CRC cell line, HT-29. This positive extract response indicates possible therapeutic value.

Cannabis Sativa targets mediobasal hypothalamic neurons to stimulate appetite

The neurobiological mechanisms that regulate the appetite-stimulatory properties of cannabis sativa are unresolved. This work examined the hypothesis that cannabinoid-1 receptor (CB1R) expressing neurons in the mediobasal hypothalamus (MBH) regulate increased appetite following cannabis vapor inhalation. Here we utilized a paradigm where vaporized cannabis plant matter was administered passively to rodents. Initial studies in rats characterized meal patterns and operant responding for palatable food following exposure to air or vapor cannabis. Studies conducted in mice used a combination of in vivo optical imaging, electrophysiology and chemogenetic manipulations to determine the importance of MBH neurons for cannabis-induced feeding behavior. Our data indicate that cannabis vapor increased meal frequency and food seeking behavior without altering locomotor activity. Importantly, we observed augmented MBH activity within distinct neuronal populations when mice anticipated or consumed food. Mechanistic experiments demonstrated that pharmacological activation of CB1R attenuated inhibitory synaptic tone onto hunger promoting Agouti Related Peptide (AgRP) neurons within the MBH. Lastly, chemogenetic inhibition of AgRP neurons attenuated the appetite promoting effects of cannabis vapor. Based on these results, we conclude that MBH neurons contribute to the appetite stimulatory properties of inhaled cannabis.

Optimizing antiemetic therapy for children undergoing chemotherapy

Chemotherapy-induced nausea and vomiting (CINV) is a common side effect of most chemotherapy agents. Suboptimal management of CINV impacts quality of life, nutrition, gastrointestinal (GI) integrity, and adherence to chemotherapy treatment plans. This article reviews the principles of CINV management, planning and implementation of antiemetic regimens, and pharmacology of the antiemetics currently available in the United States appropriate for pediatric use. With the advent of more targeted therapies, increased use of immunotherapy, and the effects of radiotherapy to the brain, spine, and abdomen, treatment of CINV now has a broader application than just for chemotherapeutics alone.

Cannabis, Cannabinoids and Cannabis-Based Medicines in Cancer Care

As medical cannabis becomes legal in more states, cancer patients are increasingly interested in the potential utility of the ancient botanical in their treatment regimen. Although eager to discuss cannabis use with their oncologist, patients often find that their provider reports that they do not have adequate information to be helpful. Oncologists, so dependent on evidence-based data to guide their treatment plans, are dismayed by the lack of published literature on the benefits of medical cannabis. This results largely from the significant barriers that have existed to effectively thwart the ability to conduct trials investigating the potential therapeutic efficacy of the plant. This is a narrative review aimed at clinicians, summarizing cannabis phytochemistry, trials in the areas of nausea and vomiting, appetite, pain and anticancer activity, including assessment of case reports of antitumor use, with reflective assessments of the quality and quantity of evidence. Despite preclinical evidence and social media claims, the utility of cannabis, cannabinoids or cannabis-based medicines in the treatment of cancer remains to be convincingly demonstrated. With an acceptable safety profile, cannabis and its congeners may be useful in managing symptoms related to cancer or its treatment. Further clinical trials should be conducted to evaluate whether the preclinical antitumor effects translate into benefit for cancer patients. Oncologists should familiarize themselves with the available database to be able to better advise their patients on the potential uses of this complementary botanical therapy.

A randomized trial of medical cannabis in patients with stage IV cancers to assess feasibility, dose requirements, impact on pain and opioid use, safety, and overall patient satisfaction

PURPOSE

The prevalence of medical cannabis (MC) use in patients with cancer is growing, but questions about safety, efficacy, and dosing remain. Conducting randomized, controlled trials (RCTs) using state-sponsored MC programs is novel and could provide data needed to guide patients and providers.

METHODS

A pilot RCT of patients with stage IV cancer requiring opioids was conducted. Thirty patients were randomized 1:1 to early cannabis (EC, n = 15) versus delayed start cannabis (DC, n = 15). The EC group obtained 3 months (3 M) of MC through a state program at no charge, while the DC group received standard oncology care without MC for the first 3 M. Patients met with licensed pharmacists at one of two MC dispensaries to determine a suggested MC dosing, formulation, and route. Patients completed surveys on pain levels, opioid/MC use, side effects, and overall satisfaction with the study.

RESULTS

Interest in the study was high as 36% of patients who met eligibility criteria ultimately enrolled. The estimated mean daily THC and CBD allotments at 3 M were 34 mg and 17 mg, respectively. A higher proportion of EC patients achieved a reduction in opioid use and improved pain control. No serious safety issues were reported, and patients reported high satisfaction.

CONCLUSION

Conducting RCTs using a state cannabis program is feasible. The addition of MC to standard oncology care was well-tolerated and may lead to improved pain control and lower opioid requirements. Conducting larger RCTs with MC in state-sponsored programs may guide oncology providers on how to safely and effectively incorporate MC for interested patients.

Cannabinoids and Terpenes: How Production of Photo-Protectants Can Be Manipulated to Enhance Cannabis sativa L. Phytochemistry

Cannabis sativa L. is cultivated for its secondary metabolites, of which the cannabinoids have documented health benefits and growing pharmaceutical potential. Recent legal cannabis production in North America and Europe has been accompanied by an increase in reported findings for optimization of naturally occurring and synthetic cannabinoid production. Of the many environmental cues that can be manipulated during plant growth in controlled environments, cannabis cultivation with different lighting spectra indicates differential production and accumulation of medically important cannabinoids, including Δ9-tetrahydrocannabinol (Δ9-THC), cannabidiol (CBD), and cannabigerol (CBG), as well as terpenes and flavonoids. Ultraviolet (UV) radiation shows potential in stimulating cannabinoid biosynthesis in cannabis trichomes and pre-harvest or post-harvest UV treatment merits further exploration to determine if plant secondary metabolite accumulation could be enhanced in this manner. Visible LED light can augment THC and terpene accumulation, but not CBD. Well-designed experiments with light wavelengths other than blue and red light will provide more insight into light-dependent regulatory and molecular pathways in cannabis. Lighting strategies such as subcanopy lighting and varied light spectra at different developmental stages can lower energy consumption and optimize cannabis PSM production. Although evidence demonstrates that secondary metabolites in cannabis may be modulated by the light spectrum like other plant species, several questions remain for cannabinoid production pathways in this fast-paced and growing industry. In summarizing recent research progress on light spectra and secondary metabolites in cannabis, along with pertinent light responses in model plant species, future research directions are presented.

Overcoming Glucocorticoid Resistance in Acute Lymphoblastic Leukemia: Repurposed Drugs Can Improve the Protocol

Glucocorticoids (GCs) are a central component of multi-drug treatment protocols against T and B acute lymphoblastic leukemia (ALL), which are used intensively during the remission induction to rapidly eliminate the leukemic blasts. The primary response to GCs predicts the overall response to treatment and clinical outcome. In this review, we have critically analyzed the available data on the effects of GCs on sensitive and resistant leukemic cells, in order to reveal the mechanisms of GC resistance and how these mechanisms may determine a poor outcome in ALL. Apart of the GC resistance, associated with a decreased expression of receptors to GCs, there are several additional mechanisms, triggered by alterations of different signaling pathways, which cause the metabolic reprogramming, with an enhanced level of glycolysis and oxidative phosphorylation, apoptosis resistance, and multidrug resistance. Due to all this, the GC-resistant ALL show a poor sensitivity to conventional chemotherapeutic protocols. We propose pharmacological strategies that can trigger alternative intracellular pathways to revert or overcome GC resistance. Specifically, we focused our search on drugs, which are already approved for treatment of other diseases and demonstrated anti-ALL effects in experimental pre-clinical models. Among them are some “truly” re-purposed drugs, which have different targets in ALL as compared to other diseases: cannabidiol, which targets mitochondria and causes the mitochondrial permeability transition-driven necrosis, tamoxifen, which induces autophagy and cell death, and reverts GC resistance through the mechanisms independent of nuclear estrogen receptors (“off-target effects”), antibiotic tigecycline, which inhibits mitochondrial respiration, causing energy crisis and cell death, and some anthelmintic drugs. Additionally, we have listed compounds that show a classical mechanism of action in ALL but are not used still in treatment protocols: the BH3 mimetic venetoclax, which inhibits the anti-apoptotic protein Bcl-2, the hypomethylating agent 5-azacytidine, which restores the expression of the pro-apoptotic BIM, and compounds targeting the PI3K-Akt-mTOR axis. Accordingly, these drugs may be considered for the inclusion into chemotherapeutic protocols for GC-resistant ALL treatments.

Cannabigerol Is a Potential Therapeutic Agent in a Novel Combined Therapy for Glioblastoma

Simple Summary

Among primary brain tumours, glioblastoma is the most aggressive. As early relapses are unavoidable despite standard-of-care treatment, the cannabinoids delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) alone or in combination have been suggested as a combined treatment strategy for glioblastomas. However, the known psychoactive effects of THC hamper its medical applications in these patients with potential cognitive impairment due to the progression of the disease. Therefore, nontoxic cannabigerol (CBG), being recently shown to exhibit anti-tumour properties in some carcinomas, is assayed here for the first time in glioblastoma with the aim to replace THC. We indeed found CBG to effectively impair the relevant hallmarks of glioblastoma progression, with comparable killing effects to THC and in addition inhibiting the invasion of glioblastoma cells. Moreover, CBG can destroy therapy-resistant glioblastoma stem cells, which are the root of cancer development and extremely resistant to various other treatments of this lethal cancer. CBG should present a new yet unexplored adjuvant treatment strategy of glioblastoma.

Abstract

Glioblastoma is the most aggressive cancer among primary brain tumours. As with other cancers, the incidence of glioblastoma is increasing; despite modern therapies, the overall mean survival of patients post-diagnosis averages around 16 months, a figure that has not changed in many years. Cannabigerol (CBG) has only recently been reported to prevent the progression of certain carcinomas and has not yet been studied in glioblastoma. Here, we have compared the cytotoxic, apoptotic, and anti-invasive effects of the purified natural cannabinoid CBG together with CBD and THC on established differentiated glioblastoma tumour cells and glioblastoma stem cells. CBG and THC reduced the viability of both types of cells to a similar extent, whereas combining CBD with CBG was more efficient than with THC. CBD and CBG, both alone and in combination, induced caspase-dependent cell apoptosis, and there was no additive THC effect. Of note, CBG inhibited glioblastoma invasion in a similar manner to CBD and the chemotherapeutic temozolomide. We have demonstrated that THC has little added value in combined-cannabinoid glioblastoma treatment, suggesting that this psychotropic cannabinoid should be replaced with CBG in future clinical studies of glioblastoma therapy.

Exploring the Use of State Medical Cannabis Legislation as a Proxy for Medical Cannabis Use Among Patients Receiving Chemotherapy

OPINION STATEMENT

The use of medical cannabis is expanding in the USA. Due to conflicting, low-quality evidence, many oncologists may not feel confident to recommend it to patients. Given the potential for legal and financial risks when conducting clinical trials with medical cannabis, the use of observational data should be explored. Observational data that directly capture medical cannabis use in relation to prescription medications and track the prevalence and patterns of cannabis use is sparse. To gain insights into the role medical cannabis plays in the pharmaceutical landscape, proxies such as cannabis legislation need to be explored. In the context of recommendation-nonadherent antiemetic prescribing among patients experiencing chemotherapy-induced nausea and vomiting, medical cannabis may be a suitable alternative to an antiemetic in states that allow medical cannabis. Findings suggest that legislation may impact the use of certain antiemetics in states with cannabis legislation in place. The presence or absence of legislation regarding medical cannabis use may serve as an early, observable surrogate marker of medical cannabis use in the community. In light of the paucity of clinical trials and observational datasets that capture cannabis use, there remains a tremendous need for the development of methodologies or standardized datasets that appropriately and reliably capture the use of medical cannabis to facilitate research into its clinical application and effect on prescription medication use. Standardizing the reporting and destigmatizing use could eliminate the dependence upon proxy measures as a substitute for more extensive data and go a long way in improving data capture, thus allowing us to generate knowledge and hypotheses from observational data until research conditions improve and allow for expanded clinical trials involving medical cannabis.

Health care provider preferences for, and barriers to, cannabis use in cancer care

Background

Limited research has been conducted about the perspectives of oncology health care providers (hcps) concerning the use of cannabis in cancer care and their potential role in advising patients. We sought to determine the barriers encountered by hcps with respect to medical cannabis and their preferred practices in this area.

Methods

An anonymous survey about cannabis was distributed to oncology hcps at the Tom Baker Cancer Centre in Calgary, Alberta. The 45-question survey measured the opinions of hcps about cannabis use and authorization in oncology.

Results

Of 103 oncology hcps who participated in the study, 75% were women. By hcp type, the most commonly reported professional groups were oncology nurse (40%), radiation therapist (9%), and pharmacist (6%). Of respondents, 75% reported providing direct care to cancer patients. More than half (69%) had spoken to a patient about cannabis in the preceding month, and 84% believed that they lacked sufficient knowledge about cannabis to make recommendations. Barriers such as monitoring the patient's use of cannabis (54%), prescribing an accurate dose (61%) or strain (53%), and having insufficient research (50%) were most commonly reported. More than half of hcps (53%) would be interested in receiving more information or training about the use of cannabis in oncology.

Conclusions

The survey indicated that this group of oncology hcps believed that they lacked sufficient knowledge about cannabis to make recommendations to patients. In addition to that lack of knowledge, a number of notable barriers were reported, and more than half the hcps indicated interest in learning more about cannabis in the future.

Cannabinoids use in adolescents and young adults with cancer: a single-center survey

OBJECTIVE

To present an investigation into the intake of cannabinoids in a population of adolescents and young adults with cancer.

METHODS

Sixty-six patients took part in the research: 27 reported having used cannabinoids, 21 before diagnosis; among the latter, 10 increased use during treatment.

RESULTS

Benefits were reported by 19% of responders regarding anxiety control, 24% for nausea, 29% for pain control and improvement of sleep, and 48% for appetite improvement.

CONCLUSIONS

Cannabis use by patients may often be unknown to caregivers. Studying this subject may help to better define important therapeutic aspects of these substances.

Medical cannabis in supportive cancer care: lessons from Canada

Medical cannabis, or cannabinoid-based products, continues to grow in popularity globally, driving the evolution of regulatory access frameworks; cancer patients and caregivers often rely on guidance from their physicians regarding cannabinoid-based treatments. But the majority of healthcare practitioners still feel unprepared and insufficiently informed to make reasonable, evidence-based recommendations about medical cannabis. More than 30 countries worldwide have now legalized access to medical cannabis; yet various nations still face arduous regulatory challenges to fulfill the needs of patients, healthcare practitioners, and other medical stakeholders. This has affected the deployment of comprehensive medical cannabis access programs adapted to cultural and social realities. With a 20-year history of legal medical cannabis access and nearly 400,000 registered patients under its federal access program, Canada serves as a model for countries which are developing their regulatory frameworks. The Canadian clinical experience in cannabinoid-based treatments is also a valuable source of lessons for healthcare professionals who wish to better understand the current evidence examining medical cannabis for oncology patients.

Vapor Cannabis Exposure Promotes Genetic Plasticity in the Rat Hypothalamus

It is well established that cannabis use promotes appetite. However, how cannabis interacts with the brain’s appetite center, the hypothalamus, to stimulate feeding behavior is unknown. A growing body of evidence indicates that the hypothalamic transcriptome programs energy balance. Here, we tested the hypothesis that cannabis targets alternative polyadenylation (APA) sites within hypothalamic transcripts to regulate transcriptomic function. To do this, we used a novel cannabis vapor exposure model to characterize feeding in adult male Long Evans rats and aligned this behavioral response with APA events using a Whole Transcriptome Termini Sequencing (WTTS-Seq) approach as well as functional RNA abundance measurements with real-time quantitative polymerase chain reactions. We found that vapor cannabis exposure promoted food intake in free-feeding and behaviorally sated rats, validating the appetite stimulating properties of cannabis. Our WTTS-Seq analysis mapped 59 unique cannabis-induced hypothalamic APAs that occurred primarily within exons on transcripts that regulate synaptic function, excitatory synaptic transmission, and dopamine signaling. Importantly, APA insertions regulated RNA abundance of Slc6a3, the dopamine transporter, suggesting a novel genetic link for cannabis regulation of brain monoamine function. Collectively, these novel data indicate that a single cannabis exposure rapidly targets a key RNA processing mechanism linked to brain transcriptome function.