Cannabidiol rather than Cannabis sativa extracts inhibit cell growth and induce apoptosis in cervical cancer cells.

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“Cervical cancer remains a global health related issue among females of Sub-Saharan Africa, with over half a million new cases reported each year.

Different therapeutic regimens have been suggested in various regions of Africa, however, over a quarter of a million women die of cervical cancer, annually. This makes it the most lethal cancer amongst black women and calls for urgent therapeutic strategies.

In this study we compare the anti-proliferative effects of crude extract of Cannabis sativa and its main compound cannabidiol on different cervical cancer cell lines.

Results obtained indicate that both cannabidiol and Cannabis sativa extracts were able to halt cell proliferation in all cell lines at varying concentrations.

They further revealed that apoptosis was induced by cannabidiol as shown by increased subG0/G1 and apoptosis through annexin V. Apoptosis was confirmed by overexpression of p53, caspase 3 and bax. Apoptosis induction was further confirmed by morphological changes, an increase in Caspase 3/7 and a decrease in the ATP levels.

CONCLUSIONS:

In conclusion, these data suggest that cannabidiol rather than Cannabis sativa crude extracts prevent cell growth and induce cell death in cervical cancer cell lines.”

http://www.ncbi.nlm.nih.gov/pubmed/27586579

“Different ethnic groups around the world use Cannabis sativa for smoking, preparing concoctions to treat diseases, and for various cultural purposes. It has been found to be effective against a variety of disorders including neurodegerative disorders, autoimmune diseases, and cancer. Cannabis sativa in particular cannabidiol, we propose it plays important role in helping the body fight cancer through inhibition of pain and cell growth.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5009497/

Cannabinoid signalling in glioma cells

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“Cannabinoids, originally derived from Cannabis sativa, as well as their endogenous and synthetic counterparts, were shown to induce apoptosis of glioma cells in vitro and tumour regression in vivo via their specific receptors, cannabinoid receptors CB1 and/or CB2.

CB2 are abnormally expressed in human gliomas and glioma cell lines. Most of the analysed gliomas expressed significant levels of CB2 receptor and the extent of CB2 expression in the tumour specimens was related to tumour malignancy.

A synthetic cannabinoid, WIN 55,212-2, down-regulated the Akt and Erk signalling pathways in C6 glioma cells that resulted in reduction of phosphorylated Bad levels, mitochondrial depolarization and activation of caspase cascade leading to apoptosis.

We examined whether synthetic cannabinoids with different receptor specificity: WIN55,212-2 (a non-selective CB1/CB2 agonist) and JWH133 (a CB2-selective agonist) affect survival of four human glioma cell lines and three primary human glioma cell lines.

WIN-55,212-2 decreased cell viability in all examined cell lines and induced cell death. Susceptibility of the cells to JWH133 treatment correlated with the CB2 expression. Cannabinoids triggered a decrease of mitochondrial membrane potential, cleavage of caspase-9 and effector caspases.

Induction of cell death by cannabinoid treatment led to the generation of a pro-apoptotic sphingolipid ceramide and disruption of signalling pathways crucial for regulation of proliferation and survival. Increased ceramide levels induced ER-stress and autophagy in drug-treated glioblastoma cells.

We conclude that cannabinoids are efficient inhibitors of human glioma cells growth, once the cells express specific type of cannabinoid receptor.”

http://springerplus.springeropen.com/articles/10.1186/2193-1801-4-S1-L11

Inhibition of autophagy and enhancement of endoplasmic reticulum stress increase sensitivity of osteosarcoma Saos-2 cells to cannabinoid receptor agonist WIN55,212-2.

“WIN55,212-2, a cannabinoid receptor agonist, can activate cannabinoid receptors, which has proven anti-tumour effects in several tumour types. Studies showed that WIN can inhibit tumour cell proliferation and induce apoptosis in diverse cancers.

However, the role and mechanism of WIN in osteosarcoma are still unclear. In this study, we examined the effect of WIN55,212-2 on osteosarcoma cell line Saos-2 in terms of cell viability and apoptosis. Meanwhile, we further explored the role of endoplasmic reticulum stress and autophagy in apoptosis induced by WIN55,212-2.

Our results showed that the cell proliferation of Saos-2 was inhibited by WIN55,212-2 in a dose-dependent and time-dependent manner. WIN55,212-2-induced Saos-2 apoptosis through mitochondrial apoptosis pathway. Meanwhile, WIN55,212-2 can induce endoplasmic reticulum stress and autophagy in Saos-2 cells. Inhibition of autophagy and enhancement of endoplasmic reticulum stress increased apoptosis induced by WIN55,212-2 in Saos-2 cells.

These findings indicated that WIN55,212-2 in combination with autophagic inhibitor or endoplasmic reticulum stress activator may shed new light on osteosarcoma treatment.”

http://www.ncbi.nlm.nih.gov/pubmed/27309350

Inhibition of human tumour prostate PC-3 cell growth by cannabinoids R(+)-Methanandamide and JWH-015: Involvement of CB2

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“We have previously shown that cannabinoids induce growth inhibition and apoptosis in prostate cancer PC-3 cells, which express high levels of cannabinoid receptor types 1 and 2 (CB1 and CB2). In this study, we investigated the role of CB2 receptor in the anti-proliferative action of cannabinoids and the signal transduction triggered by receptor ligation.

This study defines the involvement of CB2-mediated signalling in the in vivo and in vitro growth inhibition of prostate cancer cells and suggests that CB2 agonists have potential therapeutic interest and deserve to be explored in the management of prostate cancer.

Cannabinoids, the active components of Cannabis sativa and their derivatives, exert a wide spectrum of modulatory actions and pharmacological activities in the brain as well as in the periphery, and therefore, the therapeutic potential of cannabinoids has gained much attention during the past few years. One of the most exciting areas of current research in the therapeutic potential of cannabinoids is cancer.

Recent evidence suggests that cannabinoids are powerful regulators of cell growth and differentiation. They have been shown to exert anti-tumoural effects by decreasing viability, proliferation, adhesion and migration on various cancer cells, thereby suggesting the potential use of cannabinoids in the treatment of gliomas, prostate and breast cancers and malignancies of immune origin.

Overall, our data show a role for the cannabinoid receptor CB2 in the anti-tumour effect of cannabinoids on prostate cells in vitroand in vivo. There is considerable interest in the application of selective CB2 receptor agonists, which are devoid of typical marijuana-like psychoactive properties of CB1 agonists, for future cannabinoid-based anticancer therapies. Therefore, our findings point to the potential application of cannabinoid receptor type 2 ligands as anti-tumour agents in prostate cancer.”

Modulation of breast cancer cell viability by a cannabinoid receptor 2 agonist, JWH-015, is calcium dependent

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“Breast cancer is the leading cause of cancer-related deaths among women aged 34–50 worldwide, and is the most commonly diagnosed metastasizing tumor in women of all ages. Despite advances in understanding breast cancer as a disease, there remains a critical need for novel disease-modifying therapeutics.

Nonspecific cannabinoids, cannabinoid receptor 2 (CB2)-selective, as well as cannabinoid receptor 1 (CB1)-selective compounds have yielded similar antitumor results in several tumor models. The lack of neuronal expression of CB2 receptors precludes CB2 selective compounds from inducing the psychotropic effects that typically accompany CB1 activation.

 Our group and others have shown that CB2 agonists displaying selectivity for the CB2 receptor can decrease tumor cell viability and significantly attenuate cancer-induced bone pain without displaying psychoactive or addictive properties.

…antitumor effects of cannabinoids have been demonstrated in a variety of tumor models…

The antiproliferative effects of a CB2 agonist along with our previous work demonstrating significant efficacy in inhibiting bone cancer pain and slowing bone loss in a murine model of advanced breast cancer strongly suggest that CB2 agonists should be investigated in humans as adjunct therapy for advanced stages of breast cancer.

 Cannabinoid compounds, both nonspecific as well as agonists selective for either cannabinoid receptor 1 (CB1) or cannabinoid receptor 2 (CB2), have been shown to modulate the tumor microenvironment by inducing apoptosis in tumor cells in several model systems.
The results of this work characterize the actions of a CB2-selective agonist on breast cancer cells in a syngeneic murine model representing how a clinical presentation of cancer progression and metastasis may be significantly modulated by a G-protein-coupled receptor.
Several groups have shown that both nonselective cannabinoid and CB2-specific compounds decrease breast cancer viability in vitro and in vivo: Δ9-tetrahydrocannabinol and CB2-selective agonist, JWH-133, have been demonstrated to exert considerable antitumoral effects…”

Potentiation of cannabinoid-induced cytotoxicity in Mantle Cell Lymphoma through modulation of ceramide metabolism

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“Ceramide accumulation is a widely described event in cancers after various treatments.

Ceramide levels are elevated in Mantle Cell Lymphoma (MCL) cells following treatment with cannabinoids.

In previous publications we and others observed that induction of ceramide accumulation by cannabinoids leads to apoptosis in MCL, glioma and pancreatic cancer.

Here, we investigated the pathways of ceramide accumulation in the MCL cell line Rec-1 using the stable endocannabinoid analogue R(+)-methanandamide (R-MA).

Our findings suggest that R-MA induces cell death in MCL via CB1-mediated upregulation of the de novo ceramide synthesis pathway.

This is the first study showing that the cytotoxic effect of a cannabinoid can be enhanced by modulation of ceramide metabolism.

The results suggest that interference with ceramide conversion may provide a tool to enhance the targeted cell death-promoting effects of cannabinoids in MCL and other malignant lymphomas overexpressing the CB1 receptor.

Cannabinoids have been suggested as a new non-toxic therapeutic option for cancer treatment.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3077284/

Cannabinoid receptors in mantle cell lymphoma

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“Mantle cell lymphoma (MCL) is a non-curable B cell lymphoma that in several independent studies have been shown to express higher levels of CB1 and CB2 than non-malignant B cells.

The endocannabinoid system is dysregulated in many types of cancer and is involved in the regulation of survival and proliferation of cancer cells and cancer stem cells, in cancer metabolism, as well as in pro-metastatic events such as angiogenesis, migration and invasion.

Previous in vitro studies of MCL cell lines and primary ex vivo isolated tumor cells have demonstrated that high concentrations of cannabinoid receptor ligands induced proliferation arrest and programmed cell death.

All together, the data suggest that perturbations in the endocannabinoid system participate in the regulation of multi-functional cell responses regarding proliferation, migration and cell death control.

Therefore, it can be concluded that further studies on pharmacological modulation of endocannabinoid accumulation and/or signaling offers an interesting option for novel anti-lymphoma therapy.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4353235/

Cannabinoid receptor-mediated apoptosis induced by R(+)-methanandamide and Win55,212-2 is associated with ceramide accumulation and p38 activation in mantle cell lymphoma.

“We have recently shown that cannabinoids induce growth inhibition and apoptosis in mantle cell lymphoma (MCL), a malignant B-cell lymphoma that expresses high levels of cannabinoid receptor types 1 and 2 (CB(1) and CB(2)).

In the current study, the role of each receptor and the signal transduction triggered by receptor ligation were investigated.

The present data suggest that targeting CB(1)/CB(2) may have therapeutic potential for the treatment of mantle cell lymphoma.”

http://www.ncbi.nlm.nih.gov/pubmed/16936228

Modulation of breast cancer cell viability by a cannabinoid receptor 2 agonist, JWH-015, is calcium dependent

“Cannabinoid compounds, both nonspecific as well as agonists selective for either cannabinoid receptor 1 (CB1) or cannabinoid receptor 2 (CB2), have been shown to modulate the tumor microenvironment by inducing apoptosis in tumor cells in several model systems.

The mechanism of this modulation remains only partially delineated, and activity induced via the CB1 and CB2 receptors may be distinct despite significant sequence homology and structural similarity of ligands.

The results of this work characterize the actions of a CB2-selective agonist on breast cancer cells in a syngeneic murine model representing how a clinical presentation of cancer progression and metastasis may be significantly modulated by a G-protein-coupled receptor.”

https://www.dovepress.com/modulation-of-breast-cancer-cell-viability-by-a-cannabinoid-receptor-2-peer-reviewed-article-BCTT

[Cannabinoid WIN55, 212-2 inhibits proliferation, invasion and migration of human SMMC-7721 hepatocellular carcinoma cells].

“Objective To investigate the effects of WIN55, 212-2 (WIN) on the proliferation, invasion and migration of SMMC-7721 hepatocellular carcinoma cells and its underlying mechanisms. Methods SMMC-7721 cells were treated with (0, 1, 5, 10, 20) μmol/L WIN, and cell viability was determined by CCK-8 assay. The morphological changes of the cells were observed under a fluorescence microscope with Hoechst33258 staining. Cell apoptosis was measured by flow cytometry combined with annexin V-FITC/PI staining. The expression levels of apoptosis-related proteins P53, P21, Bcl-2 and Bax, and the phosphorylated AKT (p-AKT) and phosphorylated extracellular signal-regulated kinase (p-ERK) were analyzed by Western blotting. Transwell(TM) invasion assay was used to detect cell invasion ability. Would healing assay was performed to test cell migration ability. The expression level of matrix metalloproteinase 14 (MMP-14) was evaluated by Western blotting. Results WIN inhibited the proliferation of SMMC-7721 cells and induced cell apoptosis in a dose-dependent manner. After treatment with WIN, the cell nucleus concentrated and broken, indicating obvious cell apoptosis. Western blotting exhibited an up-regulation in the protein expression of P53, P21 and Bax. And the anti-apoptotic protein Bcl-2 was repressed. The expression levels of AKT, p-AKT and p-ERK were down-regulated, whereas the expression of total ERK was not obviously changed. Compared with control group, there was a significant inhibition of cell invasion and migration abilities when SMMC-7721 cells were treated with WIN. The expression level of MMP-14 decreased as well. Conclusion WIN can inhibit the proliferation of SMMC-7721 cells and induce cell apoptosis. The mechanism is associated with the activation of P53 and the inhibition of AKT, p-AKT and p-ERK. WIN can inhibit the invasion and migration of SMMC-7721 cells through down-regulating the protein expression of MMP-14.”

http://www.ncbi.nlm.nih.gov/pubmed/27126940