The effects of cannabinoids in exemestane-resistant breast cancer cells: PS181.

“Exemestane is one of the aromatase inhibitors (AI) used as first line treatment for estrogen-receptor positive breast cancer in post-menopausal women. Exemestane acts by inhibiting aromatase, the enzyme responsible for the conversion of androgens to estrogens and also by promoting apoptosis of breast cancer cells. Nevertheless, despite its therapeutic success, this AI, after prolonged treatment, can induce acquired resistance, which causes tumor relapse. Therefore, it is important to find new strategies to overcome resistance in order to improve breast cancer treatment.

Considering that the development of resistance is the main reason for endocrine treatment failure, our group decided to explore the ability of three cannabinoids, Δ9-tetrahydrocannabinol (THC), cannabidiol (CBD) and anandamide (AEA), to reverse resistance to exemestane. The THC and CBD are phytocannabinoids derived from the plant Cannabis sativa (marijuana) whereas AEA is an endocannabinoid. For that, it was used LTEDaro cells, a long-term estrogen deprived ER+ breast cancer cell line that mimics resistance to exemestane. These cells were treated with exemestane in combination with two phytocannabinoids, CBD and THC, and the endocannabinoid AEA.

The presence of CB1 and CB2 in LTEDaro cells was confirmed by Western blot analysis and the effects of the combination of cannabinoids with exemestane were evaluated by MTT and LDH assays. Cell morphology was analyzed by Giemsa and Hoechst staining.

Results: Our results demonstrate that all the cannabinoids induce a decrease in viability of exemestane-resistant cells, in a dose- and time-dependent manner, without LDH release. These results indicate that the studied cannabinoids, mainly THC and AEA, revert the resistance to exemestane, probably by inducing apoptosis, as observed in Giemsa/Hoechst stain by the presence of typical morphological features of apoptosis.

Conclusion: This study highlights the efficacy of using cannabinoids as a potential adjuvant treatment to revert resistance to AIs.”

https://www.ncbi.nlm.nih.gov/pubmed/32258721

https://journals.lww.com/pbj/fulltext/2017/09000/The_effects_of_cannabinoids_in.118.aspx

Cannabidiol (CBD) Inhibited Rhodamine-123 Efflux in Cultured Vascular Endothelial Cells and Astrocytes Under Hypoxic Conditions.

Archive of "Frontiers in Behavioral Neuroscience".“Despite the constant development of new antiepileptic drugs (AEDs), more than 30% of patients develop refractory epilepsy (RE) characterized by a multidrug-resistant (MDR) phenotype. The “transporters hypothesis” indicates that the mechanism of this MDR phenotype is the overexpression of ABC transporters such as P-glycoprotein (P-gp) in the neurovascular unit cells, limiting access of the AEDs to the brain.

Recent clinical trials and basic studies have shown encouraging results for the use of cannabinoids in RE, although its mechanisms of action are still not fully understood. Here, we have employed astrocytes and vascular endothelial cell cultures subjected to hypoxia, to test the effect of cannabidiol (CBD) on the P-gp-dependent Rhodamine-123 (Rho-123) efflux.

Results show that during hypoxia, intracellular Rho-123 accumulation after CBD treatment is similar to that induced by the P-gp inhibitor Tariquidar (Tq). Noteworthy, this inhibition is like that registered in non-hypoxia conditions. Additionally, docking studies predicted that CBD could behave as a P-gp substrate by the interaction with several residues in the α-helix of the P-gp transmembrane domain.

Overall, these findings suggest a direct effect of CBD on the Rho-123 P-gp-dependent efflux activity, which might explain why the CBD add-on treatment regimen in RE patients results in a significant reduction in seizure frequency.”

https://www.ncbi.nlm.nih.gov/pubmed/32256321

“Interestingly, for several thousand years, humanity has given medicinal use to Cannabis sativa (Marijuana), even for the treatment of epileptic patients. Our results indicate that, in addition to the various effects previously described by CBD, this drug can also inhibit the active efflux of Rho-123, a known P-gp substrate, in two types of cells of the NVU, in a similar (though less potent) manner to TQ. Consistently, our in silico study indicates that CBD may bind the transmembrane domain of P-gp, possibly acting as a competitive inhibitor. CBD could thus be used as an adjuvant therapy to reverse the MDR phenotype as observed in patients with RE, which could explain its recent approval as an add-on therapy to treat severe refractory childhood epilepsies.”

https://www.frontiersin.org/articles/10.3389/fnbeh.2020.00032/full

Cannabinoids as anticancer therapeutic agents.

Cell Cycle Journal are Co-Sponsoring #ACCM15 – The Cell Division Lab “The recent announcement of marijuana legalization in Canada spiked many discussions about potential health benefits of Cannabis sativaCannabinoids are active chemical compounds produced by cannabis, and their numerous effects on the human body are primarily exerted through interactions with cannabinoid receptor types 1 (CB1) and 2 (CB2). Cannabinoids are broadly classified as endo-, phyto-, and synthetic cannabinoids. In this review, we will describe the activity of cannabinoids on the cellular level, comprehensively summarize the activity of all groups of cannabinoids on various cancers and propose several potential mechanisms of action of cannabinoids on cancer cells.”

https://www.ncbi.nlm.nih.gov/pubmed/32249682

“Endocannabinoids and phytocannabinoids can be used for cancer therapy. Cannabis extracts have stronger anti-tumor capacity than single cannabinoids. Combination of several cannabinoids may have more potent effect on cancer.”

https://www.tandfonline.com/doi/abs/10.1080/15384101.2020.1742952?journalCode=kccy20

MyD88-dependent and -independent signalling via TLR3 and TLR4 are differentially modulated by Δ9-tetrahydrocannabinol and cannabidiol in human macrophages.

Journal of Neuroimmunology“Toll-like receptors (TLRs) are sensors of pathogen-associated molecules that trigger inflammatory signalling in innate immune cells including macrophages. All TLRs, with the exception of TLR3, promote intracellular signalling via recruitment of the myeloid differentiation factor 88 (MyD88) adaptor, while TLR3 signals via Toll-Interleukin-1 Receptor (TIR)-domain-containing adaptor-inducing interferon (IFN)-β (TRIF) adaptor to induce MyD88-independent signalling. Furthermore, TLR4 can activate both MyD88-dependent and -independent signalling (via TRIF).

The study aim was to decipher the impact of the highly purified plant-derived (phyto) cannabinoids Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD), when delivered in isolation and in combination (1:1), on MyD88-dependent and -independent signalling in macrophages.

TLRs are attractive therapeutic targets given their role in inflammation and initiation of adaptive immunity, and data herein indicate that both CBD and THC preferentially modulate TLR3 and TLR4 signalling via MyD88-independent mechanisms in macrophages. This offers mechanistic insight into the role of phytocannabinoids in modulating cellular inflammation.”

https://www.ncbi.nlm.nih.gov/pubmed/32244040

https://www.jni-journal.com/article/S0165-5728(20)30057-6/pdf

“Cannabinoids have been shown to exert anti-inflammatory activities in various in vivo and in vitro experimental models as well as ameliorate various inflammatory degenerative diseases. Δ9-Tetrahydrocannabinol (THC) is a major constituent of Cannabis. The second major constituent of Cannabis extract is cannabidiol (CBD). Both THC and CBD have been shown to exert anti-inflammatory properties and to modulate the function of immune cells. In summary, our results show that although both THC and CBD exert anti-inflammatory effects, the two compounds engage different, although to some extent overlapping, intracellular pathways. Both THC and CBD decrease the activation of proinflammatory signaling.”  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2804319/

CBD Reverts the Mesenchymal Invasive Phenotype of Breast Cancer Cells Induced by the Inflammatory Cytokine IL-1β.

ijms-logoCannabidiol (CBD) has been used to treat a variety of cancers and inflammatory conditions with controversial results. In previous work, we have shown that breast cancer MCF-7 cells, selected by their response to inflammatory IL-1β cytokine, acquire a malignant phenotype (6D cells) through an epithelial-mesenchymal transition (EMT).

We evaluated CBD as a potential inhibitor of this transition and inducer of reversion to a non-invasive phenotype. It decreased 6D cell viability, downregulating expression of receptor CB1. The CBD blocked migration and progression of the IL-1β-induced signaling pathway IL-1β/IL-1RI/β-catenin, the driver of EMT. 

Cannabidiol reestablished the epithelial organization lost by dispersion of the cells and re-localized E-cadherin and β-catenin at the adherens junctions. It also prevented β-catenin nuclear translocation and decreased over-expression of genes for ∆Np63α, BIRC3, and ID1 proteins, induced by IL-1β for acquisition of malignant features.

Cannabidiol inhibited the protein kinase B (AKT) activation, a crucial effector in the IL-1β/IL-1RI/β-catenin pathway, indicating that at this point there is crosstalk between IL-1β and CBD signaling which results in phenotype reversion.

Our 6D cell system allowed step-by-step analysis of the phenotype transition and better understanding of mechanisms by which CBD blocks and reverts the effects of inflammatory IL-1β in the EMT.”

https://www.ncbi.nlm.nih.gov/pubmed/32244518

https://www.mdpi.com/1422-0067/21/7/2429

Differential Inhibition of Human Nav1.2 Resurgent and Persistent Sodium Currents by Cannabidiol and GS967.

ijms-logo “Many epilepsy patients are refractory to conventional antiepileptic drugs.

Resurgent and persistent currents can be enhanced by epilepsy mutations in the Nav1.2 channel, but conventional antiepileptic drugs inhibit normal transient currents through these channels, along with aberrant resurgent and persistent currents that are enhanced by Nav1.2 epilepsy mutations.

Pharmacotherapies that specifically target aberrant resurgent and/or persistent currents would likely have fewer unwanted side effects and be effective in many patients with refractory epilepsy.

This study investigated the effects of cannbidiol (CBD) and GS967 (each at 1 μM) on transient, resurgent, and persistent currents in human embryonic kidney (HEK) cells stably expressing wild-type hNav1.2 channels.

We found that CBD preferentially inhibits resurgent currents over transient currents in this paradigm; and that GS967 preferentially inhibits persistent currents over transient currents.

Therefore, CBD and GS967 may represent a new class of more targeted and effective antiepileptic drugs.”

https://www.ncbi.nlm.nih.gov/pubmed/32244818

https://www.mdpi.com/1422-0067/21/7/2454

Cannabinoid type 2 receptor agonist JWH133 decreases blood pressure of spontaneously hypertensive rats through relieving inflammation in the rostral ventrolateral medulla of the brain.

Journal of Hypertension | The International Society of Hypertension“Neuroinflammation in the rostral ventrolateral medulla (RVLM) has been reported to be associated with hypertension. The upregulation and activation of the cannabinoid type 2 (CB2) receptor may be part of the active process of limiting or downregulating the inflammatory process.

This study was designed to determine the role of the CB2 receptor in blood pressure (BP) through relieving neuroinflammation in the RVLM in spontaneously hypertensive rats (SHRs).

CONCLUSION:

Taken together, our results suggest that exciting the CB2 receptor relieves proinflammatory cytokine levels in the RVLM to decrease the BP, HR and RSNA in SHRs.”

https://www.ncbi.nlm.nih.gov/pubmed/32238784

https://journals.lww.com/jhypertension/Abstract/2020/05000/Cannabinoid_type_2_receptor_agonist_JWH133.15.aspx

Dosage, Efficacy and Safety of Cannabidiol Administration in Adults: A Systematic Review of Human Trials.

“Considering data from in vitro and in vivo studies, cannabidiol (CBD) seems to be a promising candidate for the treatment of both somatic and psychiatric disorders.

The aim of this review was to collect dose(s), dosage schemes, efficacy and safety reports of CBD use in adults from clinical studies.

From the controlled trials, we identified anxiolytic effects with acute CBD administration, and therapeutic effects for social anxiety disorder, psychotic disorder and substance use disorders.

There was evidence to support single dose positive effect on social anxiety disorder, short medium-term effects on symptomatic improvement in schizophrenia and lack of effect in the short medium-term on cognitive functioning in psychotic disorders.

Overall, the administration was well tolerated with mild side effects.”

https://www.ncbi.nlm.nih.gov/pubmed/32231748

https://www.jocmr.org/index.php/JOCMR/article/view/4090

Molecular Mechanism and Cannabinoid Pharmacology.

 “Since antiquity, Cannabis has provoked enormous intrigue for its potential medicinal properties as well as for its unique pharmacological effects.

The elucidation of its major cannabinoid constituents, Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD), led to the synthesis of new cannabinoids (termed synthetic cannabinoids) to understand the mechanisms underlying the pharmacology of Cannabis.

These pharmacological tools were instrumental in the ultimate discovery of the endogenous cannabinoid system, which consists of CB1 and CB2 cannabinoid receptors and endogenously produced ligands (endocannabinoids), which bind and activate both cannabinoid receptors.

CB1 receptors mediate the cannabimimetic effects of THC and are highly expressed on presynaptic neurons in the nervous system, where they modulate neurotransmitter release. In contrast, CB2 receptors are primarily expressed on immune cells.

The endocannabinoids are tightly regulated by biosynthetic and hydrolytic enzymes. Accordingly, the endocannabinoid system plays a modulatory role in many physiological processes, thereby generating many promising therapeutic targets.

An unintended consequence of this research was the emergence of synthetic cannabinoids sold for human consumption to circumvent federal laws banning Cannabis use. Here, we describe research that led to the discovery of the endogenous cannabinoid system and show how knowledge of this system benefitted as well as unintentionally harmed human health.”

https://www.ncbi.nlm.nih.gov/pubmed/32236882

https://link.springer.com/chapter/10.1007%2F164_2019_298

Editorial: The Canonical and Non-Canonical Endocannabinoid System as a Target in Cancer and Acute and Chronic Pain

frontiers in pharmacology – Retraction Watch“The endocannabinoid system (ECS) comprises the canonical receptor subtypes CB1R and CB2R and endocannabinoids (anandamide, AEA and 2-arachidonoylglycerol, 2-AG), and a “non-canonical” extended signaling network consisting of: (i) other fatty acid derivatives; (ii) the defined “ionotropic cannabinoid receptors” (TRP channels); other GPCRs (GPR55, PPARα); (iii) enzymes involved in the biosynthesis and degradation of endocannabinoids (FAAH and MAGL); and (iv) protein transporters (FABP family).The ECS is currently a hot topic due to its involvement in cancer and pain.

The current Research Topic highlights various ways the endocannabinoid system (ECS) can impact cancer and pain. Ramer et al. review the anticancer potential of the canonical and noncanonical endocannabinoid system. Morales and Jagerovic provide a much needed summary of cannabinoid ligands as promising antitumor agents in a wide variety of tumors, in contrast to their palliative applications. In their article, the authors classify cannabinoids with anticancer potential in endocannabinoids, phytocannabinoids, and synthetic cannabinoids. Moreno et al. in their review explored the value of cannabinoid receptor heteromers as potential new targets for anti-cancer therapies and as prognostic biomarkers, showing the potential of the endocannabinoid network in the anti-cancer setting as well as the clinical and ethical pitfalls behind it.

As an ensemble, these studies provide further fuel to the discussion and underline the potential for targeting the ECS at multiple levels to treat certain cancers and for pain relief. Importantly, they also help to move the focal point of the discussion beyond THC, CBD, and the cannonical receptors. Several of these reports either review or provide data to support the use of/targeting of other members of the ECS system as well as alternative natural products beyond THC and CBD.”

https://www.frontiersin.org/articles/10.3389/fphar.2020.00312/full