Amphiregulin is a factor for resistance of glioma cells to cannabinoid-induced apoptosis.

“Gliomas, one of the most malignant forms of cancer, exhibit high resistance to conventional therapies. Identification of the molecular mechanisms responsible for this resistance is therefore of great interest to improve the efficacy of the treatments against these tumors. Delta9-Tetrahydrocannabinol (THC), the major active ingredient of marijuana, and other cannabinoids inhibit tumor growth in animal models of cancer, including glioma, an effect that relies, at least in part, on the ability of these compounds to induce apoptosis of tumor cells.

…we identified the epidermal growth factor receptor ligand amphiregulin as a candidate factor to mediate the resistance of glioma cells to cannabinoid treatment… in vivo silencing of amphiregulin rendered the resistant tumors xenografts sensitive to cannabinoid antitumoral action.

Amphiregulin expression was associated with increased extracellular signal-regulated kinase (ERK) activation, which mediated the resistance to THC by blunting the expression of p8 and TRB3-two genes involved in cannabinoid-induced apoptosis of glioma cells.

 Our findings therefore identify Amphirregulin as a factor for resistance of glioma cells to THC-induced apoptosis and contribute to unraveling the molecular bases underlying the emerging notion that targeted inhibition of the EGFR pathway can improve the efficacy of antitumoral therapies.”

http://www.ncbi.nlm.nih.gov/pubmed/19229996

Stimulation of the midkine/ALK axis renders glioma cells resistant to cannabinoid antitumoral action

“Δ9-Tetrahydrocannabinol (THC), the major active ingredient of marijuana, and other cannabinoids inhibit tumor growth in animal models of cancer, including glioma, an effect that relies, at least in part, on the stimulation of autophagy-mediated apoptosis in tumor cells. 

…Altogether, our findings identify Mdk as a pivotal factor involved in the resistance of glioma cells to THC pro-autophagic and antitumoral action, and suggest that selective targeting of the Mdk/ALK axis could help to improve the efficacy of antitumoral therapies for gliomas.”

Full text: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3131933/

Effect of a synthetic cannabinoid agonist on the proliferation and invasion of gastric cancer cells.

“Although cannabinoids are associated with antineoplastic activity in a number of cancer cell types, the effect in gastric cancer cells has not been clarified. In the present study, we investigated the effects of a cannabinoid agonist on gastric cancer cell proliferation and invasion.

The cannabinoid agonist WIN 55,212-2 inhibited the proliferation of human gastric cancer cells in a dose-dependent manner and that this effect was mediated partially by the CB(1) receptor. We also found that WIN 55,212-2 induced apoptosis and down-regulation of the phospho-AKT expression in human gastric cancer cells. Furthermore, WIN 55,212-2 treatment inhibited the invasion of gastric cancer cells, and down-regulated the expression of MMP-2 and VEGF-A through the cannabinoid receptors.

Our results open the possibilities in using cannabinoids as a new gastric cancer therapy.”

http://www.ncbi.nlm.nih.gov/pubmed/20336665

Antiproliferative mechanism of a cannabinoid agonist by cell cycle arrest in human gastric cancer cells.

“For gastric cancers, the antineoplastic activity of cannabinoids has been investigated in only a few reports and knowledge regarding the mechanisms involved is limited. We have reported previously that treatment of gastric cancer cells with a cannabinoid agonist significantly decreased cell proliferation and induced apoptosis.

Here, we evaluated the effects of cannabinoids on various cellular mediators involved in cell cycle arrest in gastric cancer cells. AGS and MKN-1 cell lines were used as human gastric cancer cells and WIN 55,212-2 as a cannabinoid agonist.

 …Cell cycle arrest preceded apoptotic response. Thus, this cannabinoid agonist can reduce gastric cancer cell proliferation via G1 phase cell cycle arrest, which is mediated via activation of the MAPK pathway and inhibition of pAKT.”

http://www.ncbi.nlm.nih.gov/pubmed/21312237

Delta–9 Tetrahydrocannabinol inhibits growth and metastasis of lung cancer – Harvard University

“Lung cancer is the major cause of cancer-related mortality worldwide.Many of these over-express epidermal growth factor receptor(EGFR), and are usually highly aggressive and resistant to chemotherapy.

Recent studies have shown that {Delta}-9 Tetrahydrocannabinol (THC),the major component of Cannabis sativa, possess anti-tumor propertiesagainst various types of cancers.

 However, not much is knownabout its effect on lung cancer. In this study, we sought tocharacterize the effect of THC on EGF-induced growth and metastasisof human non small lung cancer cell (NSCLC) lines A549 and SW-1573.

We demonstrate that these cell lines and primary tumor samplesderived from lung cancer patients express cannabinoids receptorsCB1 and CB2, the known targets for THC action. We further showthat THC inhibits EGF-induced growth in these cell lines. Inaddition THC attenuated EGF-stimulated chemotaxis and chemoinvasion.Next we characterized the effect of THC on in vivo lung cancergrowth and metastasis in a murine model. A549 cells were implantedin SCID mice (n=6 per group) through subcutaneous and intravenousinjections to generate subcutaneous and lung metastatic cancer,respectively. THC (5mg/kg body wt.) was administered once dailythrough intraperitoneal injections for 21 days. The mice wereanalyzed for tumor growth and lung metastasis.

 A significantreduction (~50%) in tumor weight and volume were observed inTHC treated animals compared to the vehicle treated animals.THC treated animals also showed a significant (~60%) reductionin macroscopic lesions on the lung surface in comparison tovehicle treated control. Immunohistochemical analysis of thetumor samples from THC treated animals revealed anti-proliferativeand anti-angiogenic effects of THC with significant reductionin staining for Ki67, a proliferative marker and CD31, an endothelialmarker indicative of vascularization. Investigation into thesignaling events associated with reduced EGF-induced functionaleffects revealed that THC also inhibits EGF-induced Akt phosphorylation.Akt is a central signaling molecule of EGFR-mediated signalingpathways and it regulates a diverse array of cellular functions,including proliferation, angiogenesis, invasion and apoptosis.

Cumulatively, these studies indicate that THC has anti-tumorigenic and anti-metastatic effects against lung cancer. Novel therapies against EGFR overexpressing, aggressive and chemotherapy resistant lung cancers may include targeting the cannabinoids receptors.”

http://www.aacrmeetingabstracts.org/cgi/content/meeting_abstract/2007/1_Annual_Meeting/4749%20?maxtoshow&hits=80&RESULTFORMAT&fulltext=cannabinoid&searchid=1&FIRSTINDEX=1760&resourcetype=HWCIT

Anti-proliferative effects of anandamide in human hepatocellular carcinoma cells.

“In our previous study, we reported that the cannabinoid receptors CB1 and CB2 are overexpressed in human hepatocellular carcinoma (HCC) tissues. Recently, the antitumor potential of the endogenous cannabinoid anandamide (AEA) has also been addressed. The present study was conducted to investigate the anti-proliferative effects of AEA in HCC cells…

The results of this study demonstrated that AEA inhibited the proliferation of Huh7 cells, resulted in G1 cell cycle arrest and induced apoptosis…

This study defines the anti-proliferative effects of anandamide in HCC cells and suggests that AEA has therapeutic potential in the management of HCC patients.”

http://www.ncbi.nlm.nih.gov/pubmed/22970038

Antitumor Effects of THC.

“1-Trans-[delta.sup.9]-tetrahydrocannabinol (THC) the main active component of marijuana, has been shown to exhibit anticancer activity.

Galve-Roperh et al. reported that intratumoral administration of THC induces apoptosis of transformed neural cells in culture, and also induces a considerable regression of malignant gliomas in Wistar rats and in mice… These authors suggest that their “results may provide the basis for a new therapeutic approach for the treatment of malignant gliomas.”

Thus, in our studies, rats and mice that received THC for 2 years exhibited body weight reductions, enhanced survival rates, and decreased tumor incidences in several sites, mainly organs under hormonal control.

These earlier experimental carcinogenesis results on THC clearly lend further validity to the notion that cannabinoids may indeed be anticarcinogenic.”

http://www.thefreelibrary.com/Antitumor+Effects+of+THC.-a068148345

“Antitumor effects of THC.” http://www.ncbi.nlm.nih.gov/pubmed/11097557

Inhibition of skin tumor growth and angiogenesis in vivo by activation of cannabinoid receptors

“Cannabinoids inhibit skin tumor growth in vivo. Here we show that the CB1 and the CB2 receptor are expressed in normal skin and skin tumors of mice and humans. In cell culture experiments pharmacological activation of cannabinoid receptors induced the apoptotic death of tumorigenic epidermal cells, whereas the viability of nontransformed epidermal cells remained unaffected. Local administration of the mixed CB1/CB2 agonist WIN-55,212-2 or the selective CB2 agonist JWH-133 induced a considerable growth inhibition of malignant tumors generated by inoculation of epidermal tumor cells into nude mice. Cannabinoid-treated tumors showed an increased number of apoptotic cells.

 

Cannabinoids, the active components of Cannabis sativa linnaeus (marijuana)…

Marijuana and its derivatives have been used in medicine for many centuries, and currently there is a renaissance in the study of the therapeutic effects of cannabinoids… cannabinoids may be potential antitumoral agents owing to their ability to induce the regression of various types of tumors, including lung adenocarcinoma, glioma, and thyroid epithelioma in animal models.

This background prompted us to explore whether (a) the skin and skin tumors express cannabinoid receptors; (b) cannabinoid receptor activation exerts a growth-inhibiting action on skin tumors in vivo; and (c) inhibition of angiogenesis is implicated in the anti-tumoral effect of cannabinoids.

Our data show that (a) CB1 and CB2 receptors are present in the skin and skin tumors; (b) local cannabinoid receptor activation induces the regression of skin tumors in vivo; and (c) at least two mechanisms may be involved in this action: direct apoptosis of tumor cells and inhibition of tumor angiogenesis.

These results support a new therapeutic approach for the treatment of skin tumors.”

Full text: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC151833/

Cannabinoids Halt Pancreatic Cancer, Breast Cancer Growth, Studies Say

“Compounds in cannabis inhibit cancer cell growth in human breast cancer cell lines and in pancreatic tumor cell lines, according to a pair of preclinical trials published in the July issue of the journal of the American Association for Cancer Research.

In one trial, investigators at Complutense University in Spain and the Institut National de la Sante et de la Recherche Medicale (INSERM) in France assessed the anti-cancer activity of cannabinoids in pancreatic cancer cell lines and in animals. Cannabinoid administration selectively increased apoptosis (programmed cell death) in pancreatic tumor cells while ignoring healthy cells, researchers found. In addition, “cannabinoid treatment inhibited the spreading of pancreatic tumor cells … and reduced the growth of tumor cells” in animals.

“These findings may contribute to … a new therapeutic approach for the treatment of pancreatic cancer,” authors concluded.

In the second trial, investigators at Spain’s Complutense University reported that THC administration “reduces human breast cancer cell proliferation [in vitro] by blocking the progression of the cell cycle and by inducing apoptosis.” Authors concluded that their findings “may set the bases for a cannabinoid therapy for the management of breast cancer.”

Previous preclinical data published in May in the Journal of Pharmacological and Experimental Therapeutics reported that non-psychoactive cannabinoids, particularly cannabidiol (CBD), dramatically halt the spread of breast cancer cells and recommended their use in cancer therapy.

Separate trials have also shown cannabinoids to reduce the size and halt the spread of glioma (brain tumor) cells in animals and humans in a dose dependent manner. Additional preclinical studies have demonstrated cannabinoids to inhibit cancer cell growth and selectively trigger malignant cell death in skin cancer cells, leukemic cells, lung cancer cells, and prostate carcinoma cells, among other cancerous cell lines.”

http://norml.org/news/2006/07/06/cannabinoids-halt-pancreatic-cancer-breast-cancer-growth-studies-say

Cannabinoids Induce Apoptosis of Pancreatic Tumor Cells

 “Pancreatic adenocarcinomas are among the most malignant forms of cancer and, therefore, it is of especial interest to set new strategies aimed at improving the prognostic of this deadly disease. The present study was undertaken to investigate the action of cannabinoids, a new family of potential antitumoral agents, in pancreatic cancer. We show that cannabinoid receptors are expressed in human pancreatic tumor cell lines …

 Cannabinoids… reduced the growth of tumor cells in two animal models of pancreatic cancer. In addition, cannabinoid treatment inhibited the spreading of pancreatic tumor cells. Moreover, cannabinoid administration selectively increased apoptosis and TRB3 expression in pancreatic tumor cells but not in normal tissue… results presented here show that cannabinoids lead to apoptosis of pancreatic tumor cells via a CB2 receptor and de novo synthesized ceramide-dependent up-regulation of p8 and the endoplasmic reticulum stress–related genes ATF-4 and TRB3.

 These findings may contribute to set the basis for a new therapeutic approach for the treatment of pancreatic cancer.

In conclusion, results presented here show that cannabinoids exert a remarkable antitumoral effect on pancreatic cancer cells in vitro and in vivo…

 These findings may help to set the basis for a new therapeutic approach for the treatment of this deadly disease.”

http://www.420magazine.com/forums/pancreatic-cancer/145013-cannabinoids-induce-apoptosis-pancreatic-tumor-cells.html

 

Cannabinoids Induce Apoptosis of Pancreatic Tumor Cells via Endoplasmic Reticulum Stress–Related Genes

 

Full text: http://cancerres.aacrjournals.org/content/66/13/6748.long