Monocyclic Quinone Structure-Activity Patterns: Synthesis of Catalytic Inhibitors of Topoisomerase II with Potent Antiproliferative Activity.

Publication cover image“The monocyclic 1,4-benzoquinone, HU-331, the direct oxidation product of cannabidiol, inhibits the catalytic activity of topoisomerase II but without inducing DNA strand breaks or generating free radicals, and unlike many fused-ring quinones exhibits minimal cardiotoxicity. Thus, monocyclic quinones have potential as anticancer agents, and investigation of the structural origins of their biological activity is warranted. New syntheses of cannabidiol and (±)-HU-331 are here reported. Integrated synthetic protocols afforded a wide range of polysubstituted resorcinol derivatives; many of the corresponding novel 2-hydroxy-1,4-benzoquinone derivatives are potent inhibitors of the catalytic activity of topoisomerase II, some more so than HU-331, whose monoterpene unit replaced by a 3-cycloalkyl unit conferred increased antiproliferative properties in cell lines with IC50 values extending below 1 mM, and greater stability in solution than HU-331. The principal pharmacophore of quinones related to HU-331 was identified. Selected monocyclic quinones show potential for the development of new anticancer agents.”

https://www.ncbi.nlm.nih.gov/pubmed/31778038

https://onlinelibrary.wiley.com/doi/abs/10.1002/cmdc.201900548

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Cannabidiol promotes apoptosis via regulation of XIAP/Smac in gastric cancer.

Image result for cell death and disease“According to recent studies, Cannabidiol (CBD), one of the main components of Cannabis sativa, has anticancer effects in several cancers. However, the exact mechanism of CBD action is not currently understood.

Here, CBD promoted cell death in gastric cancer.

We suggest that CBD induced apoptosis by suppressing X-linked inhibitor apoptosis (XIAP), a member of the IAP protein family. CBD reduced XIAP protein levels while increasing ubiquitination of XIAP. The expression of Smac, a known inhibitor of XIAP, was found to be elevated during CBD treatment. Moreover, CBD treatment increased the interaction between XIAP and Smac by increasing Smac release from mitochondria to the cytosol. CBD has also been shown to affect mitochondrial dysfunction.

Taken together, these results suggest that CBD may have potential as a new therapeutic target in gastric cancer.”

https://www.ncbi.nlm.nih.gov/pubmed/31699976

“In conclusion, our study showed that CBD induces apoptotic cell death in gastric cancer cells, which is triggered by ER stress generation and subsequent XIAP inhibition by Smac. Taken together, our results suggest the potential of CBD in novel treatments against gastric cancer.”

 https://www.nature.com/articles/s41419-019-2001-7

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Anticancer effects of n-3 EPA and DHA and their endocannabinoid derivatives on breast cancer cell growth and invasion.

Prostaglandins, Leukotrienes and Essential Fatty Acids Home“The anticancer effects of the omega-3 long chain polyunsaturated fatty acids (LCPUFA), EPA and DHA may be due, at least in part, to conversion to their respective endocannabinoid derivatives, eicosapentaenoyl-ethanolamine (EPEA) and docosahexaenoyl-ethanolamine (DHEA).

Here, the effects of EPEA and DHEA and their parent compounds, EPA and DHA, on breast cancer (BC) cell function was examined. EPEA and DHEA exhibited greater anti-cancer effects than EPA and DHA in two BC cells (MCF-7 and MDA-MB-231) whilst displaying no effect in non-malignant breast cells (MCF-10a).

Both BC lines expressed CB1/2 receptors that were responsible, at least partly, for the observed anti-proliferative effects of the omega-3 endocannabinoids as determined by receptor antagonism studies. Additionally, major signalling mechanisms elicited by these CB ligands included altered phosphorylation of p38-MAPK, JNK, and ERK proteins.

Both LCPUFAs and their endocannabinoids attenuated the expression of signal proteins in BC cells, albeit to different extents depending on cell type and lipid effectors. These signal proteins are implicated in apoptosis and attenuation of BC cell migration and invasiveness.

Furthermore, only DHA reduced in vitro MDA-MB-231 migration whereas both LCPUFAs and their endocannabinoids significantly inhibited invasiveness. This finding was consistent with reduced integrin β3 expression observed with all treatments and reduced MMP-1 and VEGF with DHA treatment.

Attenuation of cell viability, migration and invasion of malignant cells indicates a potential adjunct nutritional therapeutic use of these LCPUFAs and/or their endocannabinoids in treatment of breast cancer.”

https://www.ncbi.nlm.nih.gov/pubmed/31679810

https://www.plefa.com/article/S0952-3278(19)30112-7/fulltext

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Antitumor Activity of Abnormal Cannabidiol and Its Analog O-1602 in Taxol-Resistant Preclinical Models of Breast Cancer.

Image result for frontiers in pharmacology“Cannabinoids exhibit anti-inflammatory and antitumorigenic properties.

Contrary to most cannabinoids present in the Cannabis plant, some, such as O-1602 and abnormal cannabidiol, have no or only little affinity to the CB1 or CB2 cannabinoid receptors and instead exert their effects through other receptors.

Here, we investigated whether the synthetic regioisomers of cannabidiol, abnormal cannabidiol, and a closely related compound, O-1602, display antitumorigenic effects in cellular models of breast cancer and whether it could reduce tumorigenesis in vivo.

Several studies have shown the effects of cannabinoids on chemotherapy-sensitive breast cancer cell lines, but less is known about the antitumorigenic effects of cannabinoids in chemotherapy-resistant cell lines.

Paclitaxel-resistant MDA-MB-231 and MCF-7 breast cancer cell lines were used to study the effect of O-1602 and abnormal cannabidiol on viability, apoptosis, and migration. The effects of O-1602 and abnormal cannabidiol on cell viability were completely blocked by the combination of GPR55 and GPR18-specific siRNAs. Both O-1602 and abnormal cannabidiol decreased viability in paclitaxel-resistant breast cancer cells in a concentration-dependent manner through induction of apoptosis. The effect of these cannabinoids on tumor growth in vivo was studied in a zebrafish xenograft model. In this model, treatment with O-1602 and abnormal cannabidiol (2 µM) significantly reduced tumor growth.

Our results suggest that atypical cannabinoids, like O-1602 and abnormal cannabidiol, exert antitumorigenic effects on paclitaxel-resistant breast cancer cells. Due to their lack of central sedation and psychoactive effects, these atypical cannabinoids could represent new leads for the development of additional anticancer treatments when resistance to conventional chemotherapy occurs during the treatment of breast and possibly other cancers.”

https://www.ncbi.nlm.nih.gov/pubmed/31611800

“Our results suggest that some cannabinoids acting through the GPR55 and/or GPR18 receptors can be helpful in inducing apoptosis in breast cancer cell lines that are unresponsive to paclitaxel. The effects of O-1602 and Abn-CBD on cell viability were observed both in vitro and in a zebrafish xenograft model. These drugs were also reducing cell migration. Taken together, even if no synergistic antitumor effect is always observed when cannabinoids and chemotherapeutic agents are combined as an anticancer treatment, cannabinoids can still provide anticancer benefits on top of their palliative effects. This is particularly important in the context of cancers that have developed resistance to current chemotherapies.”

https://www.frontiersin.org/articles/10.3389/fphar.2019.01124/full

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Cannabidiol directly targets mitochondria and disturbs calcium homeostasis in acute lymphoblastic leukemia.

 Image result for cell death & disease“Anticancer properties of non-psychoactive cannabinoid cannabidiol (CBD) have been demonstrated on tumors of different histogenesis. Different molecular targets for CBD were proposed, including cannabinoid receptors and some plasma membrane ion channels. Here we have shown that cell lines derived from acute lymphoblastic leukemia of T lineage (T-ALL), but not resting healthy T cells, are highly sensitive to CBD treatment. CBD effect does not depend on cannabinoid receptors or plasma membrane Ca2+-permeable channels. Instead, CBD directly targets mitochondria and alters their capacity to handle Ca2+. At lethal concentrations, CBD causes mitochondrial Ca2+ overload, stable mitochondrial transition pore formation and cell death. Our results suggest that CBD is an attractive candidate to be included into chemotherapeutic protocols for T-ALL treatment.”

https://www.ncbi.nlm.nih.gov/pubmed/31611561

“Considering the pivotal role of mitochondria in oncogenic re-programming, CBD may be plausible candidate to be included into chemotherapeutic protocols.”

https://www.nature.com/articles/s41419-019-2024-0

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Cannabis use in cancer: a survey of the current state at BC Cancer before recreational legalization in Canada.

Image result for Curr Oncol.“Cancer patients experience multiple symptoms throughout their illness, and some report benefit from the use of cannabis. There are concerns that many patients are accessing products inappropriate for their situation and potentially putting themselves at risk.

In the present study, we aimed to capture the prevalence of cannabis use among cancer patients at BC Cancer before recreational legalization in Canada and to identify the reasons that patients take cannabis, the various routes of administration they use, and the reasons that prior users stopped.

RESULTS:

Of surveys sent to 2998 patients, 821 (27.4%) were returned and included in analysis. Of those respondents, 23% were currently using cannabis-based products, almost exclusively for medical purposes, and an additional 28% had been users in the past (most often recreationally). Of the patients currently using cannabis, 31% had medical authorization. The most common symptoms that the current users were targeting were pain, insomnia, nausea, and anxiety; many were also hoping for anticancer effects.

CONCLUSIONS:

More than half the respondents had tried cannabis at some time, and almost one quarter of respondents were currently taking cannabis to help manage their symptoms or treat their cancer, or both. Many more patients would consider use with appropriate guidance from a health care professional. More research is needed to inform physicians and patients about safe uses and doses and about the potential adverse effects of cannabis use.”

https://www.ncbi.nlm.nih.gov/pubmed/31548810

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Evaluation of the effects of cannabinoids CBD and CBG on human ovarian cancer cells in vitro

University of Huddersfield“Ovarian cancer, with over a 90% reoccurrence within 18 months of treatment, and approximately a 30% mortality rate after 5 years, is the leading cause of death in cases of gynaecological malignancies. Acquired resistance, and toxic side effects by clinically used agents are major challenges associated with current treatments, indicating the need for new approaches in ovarian cancer treatment.

Increased tumour cell proliferation associated with upregulation of cannabinoid (CB) receptors has been observed in ovarian cancer. As cannabinoids reported to bind to CB receptors, and can potentially modulate their downstream signalling, this raises the possibility of cannabinoids as potential anticancer drugs for ovarian cancer treatment.

Amongst the cannabinoids, non-psychoactive CBD and CBG have been shown to have anticancer activities towards prostate and colon cancer cells through multiple mechanisms of action. However, CBD and CBG have yet to be investigated in relation to ovarian cancer therapy either in vitro or in vivo.

Aim:

The aims of this study were to evaluate the potential cytotoxic effects of CBD and CBG in human ovarian cancer cells, their ability to potentiate existing clinically used agents for ovarian cancer, and to perform initial mode of action studies in vitro.

Conclusions:

Both CBD and CBG showed preferential cytotoxicity against the ovarian cancer cells analysed compared to the non-cancer cells; however, this was less than for carboplatin. Importantly, in contrast to carboplatin, CBD and CBG showed similar activity towards cisplatin sensitive and cisplatin resistant cells indicating distinctive mechanisms of action to platinum drugs.

Preferential cytotoxicity towards cancer cells in vitro and ability to potentiate carboplatin and overcome cisplatin resistance identify CBD and CBG as promising candidates that warrant further investigation, both in terms of detailed mechanism of action studies and also in vivo studies to assess whether this promising activity translates into an in vivo setting and their potential for further progression towards the clinic.”

http://eprints.hud.ac.uk/id/eprint/34866/

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Preclinical evidence on the anticancer properties of phytocannabinoids

Image result for CROSBI“Phytocannabinoids are unique terpenophenolic compounds predominantly produced in the glandular trichomes of the cannabis plant (Cannabis sativa L.). The delta-9- tetrahydrocannabinol (THC) is the main active constituent responsible for the plant’s psychoactive effect and, together with the non- psychoactive cannabidiol (CBD), the most investigated naturally occurring cannabinoid.

The first report on the antitumor properties of cannabis compounds appeared more than forty years ago, but the potential of targeting the endocannabinoid system in cancer has recently attracted increasing interest. Our study aimed to review the last decade’s findings on the anticancer potential of plant- derived cannabinoids and the possible mechanisms of their activity.

A large body of in vitro data has been accumulated demonstrating that phytocannabinoids affect a wide spectrum of tumor cells, including gliomas, neuroblastomas, hepatocarcinoma as well as skin, prostate, breast, cervical, colon, pancreatic, lung and hematological cancer.

It has been found that they can stop the uncontrolled growth of cancer cells through the cell-cycle arrest, inhibition of cell proliferation and induction of autophagy and apoptosis. They can also block all the steps of tumor progression, including tumor cell migration, adhesion and invasion as well as angiogenesis. The observed effects are mainly mediated by the cannabinoid CB1 and/or CB2 receptors, although some other receptors and mechanisms unrelated to receptor stimulation may also be involved.

The majority of available animal studies confirmed that phytocannabinoids are capable of effectively decreasing cancer growth and metastasis in vivo. THC was found to be effective against experimental glioma, liver, pancreatic, breast and lung cancer while CBD showed activity against glioma and neuroblastoma, melanoma, colon, breast, prostate and lung cancer. Further in vitro and in vivo studies also greatly support their use in combination with traditional chemotherapy or radiotherapy, which results in improved efficiency, attenuated toxicity or reduced drug resistance.

Taken together most of available preclinical results emphasize the extensive therapeutic potential of THC and CBD in various types of cancers. The potential clinical interest of cannabinoids is additionally suggested by their selectivity for tumor cells as well as their good tolerance and the absence of normal tissue toxicity, which are still the major limitations of most conventional drugs. The accumulated preclinical evidence strongly suggests the need for clinical testing of cannabinoids in cancer patients.”

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Terpenoids and Phytocannabinoids Co-Produced in Cannabis Sativa Strains Show Specific Interaction for Cell Cytotoxic Activity.

molecules-logo“Mixtures of different Cannabis sativa phytocannabinoids are more active biologically than single phytocannabinoids. However, cannabis terpenoids as potential instigators of phytocannabinoid activity have not yet been explored in detail.

Terpenoid groups were statistically co-related to certain cannabis strains rich in Δ9-tetrahydrocannabinolic acid (THCA) or cannabidiolic acid (CBDA), and their ability to enhance the activity of decarboxylase phytocannabinoids (i.e., THC or CBD) was determined.

Analytical HPLC and GC/MS were used to identify and quantify the secondary metabolites in 17 strains of C. sativa, and correlations between cannabinoids and terpenoids in each strain were determined. Column separation was used to separate and collect the compounds, and cell viability assay was used to assess biological activity.

We found that in “high THC” or “high CBD” strains, phytocannabinoids are produced alongside certain sets of terpenoids. Only co-related terpenoids enhanced the cytotoxic activity of phytocannabinoids on MDA-MB-231 and HCT-116 cell lines.

This was found to be most effective in natural ratios found in extracts of cannabis inflorescence. The correlation in a particular strain between THCA or CBDA and a certain set of terpenoids, and the partial specificity in interaction may have influenced the cultivation of cannabis and may have implications for therapeutic treatments.”

https://www.ncbi.nlm.nih.gov/pubmed/31438532

https://www.mdpi.com/1420-3049/24/17/3031

“Anticancer Terpenoids” https://link.springer.com/chapter/10.1007/978-3-319-14027-8_5

“Anticancer effects of phytocannabinoids” https://www.ncbi.nlm.nih.gov/pubmed/28560402

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Opportunities for cannabis in supportive care in cancer.

 Related image“Cannabis has the potential to modulate some of the most common and debilitating symptoms of cancer and its treatments, including nausea and vomiting, loss of appetite, and pain.

However, the dearth of scientific evidence for the effectiveness of cannabis in treating these symptoms in patients with cancer poses a challenge to clinicians in discussing this option with their patients. A review was performed using keywords related to cannabis and important symptoms of cancer and its treatments.

Literature was qualitatively reviewed from preclinical models to clinical trials in the fields of cancer, human immunodeficiency virus (HIV), multiple sclerosis, inflammatory bowel disease, post-traumatic stress disorder (PTSD), and others, to prudently inform the use of cannabis in supportive and palliative care in cancer.

There is a reasonable amount of evidence to consider cannabis for nausea and vomiting, loss of appetite, and pain as a supplement to first-line treatments. There is promising evidence to treat chemotherapy-induced peripheral neuropathy, gastrointestinal distress, and sleep disorders, but the literature is thus far too limited to recommend cannabis for these symptoms.

Scant, yet more controversial, evidence exists in regard to cannabis for cancer- and treatment-related cognitive impairment, anxiety, depression, and fatigue. Adverse effects of cannabis are documented but tend to be mild.

Cannabis has multifaceted potential bioactive benefits that appear to outweigh its risks in many situations. Further research is required to elucidate its mechanisms of action and efficacy and to optimize cannabis preparations and doses for specific populations affected by cancer.”

https://www.ncbi.nlm.nih.gov/pubmed/31413731

https://journals.sagepub.com/doi/10.1177/1758835919866362

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