http://www.ncbi.nlm.nih.gov/pubmed/27342953
http://gut.bmj.com/content/early/2016/06/24/gutjnl-2016-312108.extract
Targeting cannabinoid receptors in hepatocellular carcinoma?
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Category Archives: Liver Cancer
Opposite roles of cannabinoid receptors 1 and 2 in hepatocarcinogenesis.
“The endocannabinoid system (ECS) exerts key roles in the development of liver fibrosis and fatty liver, two diseases that promote the development of hepatocellular carcinoma (HCC).
Although cannabinoids exert potent antitumour effects in vitro, the contribution of the ECS to carcinogenesis in vivo remains elusive.
CONCLUSIONS:
Similar to their role in fibrogenesis, CB1 and CB2 exert opposite effects on hepatocarcinogenesis and may provide novel therapeutic targets.”
[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.”
ENDOCANNABINOID SYSTEM: A multi-facet therapeutic target.
“Cannabis sativa is also popularly known as marijuana. It is being cultivated and used by man for recreational and medicinal purposes from many centuries.
Study of cannabinoids was at bay for very long time and its therapeutic value could not be adequately harnessed due to its legal status as proscribed drug in most of the countries.
The research of drugs acting on endocannabinoid system has seen many ups and down in recent past. Presently, it is known that endocannabinoids has role in pathology of many disorders and they also serve “protective role” in many medical conditions.
Several diseases like emesis, pain, inflammation, multiple sclerosis, anorexia, epilepsy, glaucoma, schizophrenia, cardiovascular disorders, cancer, obesity, metabolic syndrome related diseases, Parkinson’s disease, Huntington’s disease, Alzheimer’s disease and Tourette’s syndrome could possibly be treated by drugs modulating endocannabinoid system.
Presently, cannabinoid receptor agonists like nabilone and dronabinol are used for reducing the chemotherapy induced vomiting. Sativex (cannabidiol and THC combination) is approved in the UK, Spain and New Zealand to treat spasticity due to multiple sclerosis. In US it is under investigation for cancer pain, another drug Epidiolex (cannabidiol) is also under investigation in US for childhood seizures. Rimonabant, CB1 receptor antagonist appeared as a promising anti-obesity drug during clinical trials but it also exhibited remarkable psychiatric side effect profile. Due to which the US Food and Drug Administration did not approve Rimonabant in US. It sale was also suspended across the EU in 2008.
Recent discontinuation of clinical trial related to FAAH inhibitor due to occurrence of serious adverse events in the participating subjects could be discouraging for the research fraternity. Despite of some mishaps in clinical trials related to drugs acting on endocannabinoid system, still lot of research is being carried out to explore and establish the therapeutic targets for both cannabinoid receptor agonists and antagonists.
One challenge is to develop drugs that target only cannabinoid receptors in a particular tissue and another is to invent drugs that acts selectively on cannabinoid receptors located outside the blood brain barrier. Besides this, development of the suitable dosage forms with maximum efficacy and minimum adverse effects is also warranted.
Another angle to be introspected for therapeutic abilities of this group of drugs is non-CB1 and non-CB2 receptor targets for cannabinoids.
In order to successfully exploit the therapeutic potential of endocannabinoid system, it is imperative to further characterize the endocannabinoid system in terms of identification of the exact cellular location of cannabinoid receptors and their role as “protective” and “disease inducing substance”, time-dependent changes in the expression of cannabinoid receptors.”
Exogenous hepatitis B virus envelope proteins induce endoplasmic reticulum stress: involvement of cannabinoid axis in liver cancer cells.
“HBV represents the most common chronic viral infection and major cause of hepatocellular carcinoma (HCC), although its exact role in liver tumorigenesis is unclear. Massive storage of the small (SHBs), middle (MHBs) and large surface (LHBs) HBV envelope proteins leads to cell stress and sustained inflammatory responses. Cannabinoid (CB) system is involved in the pathogenesis of liver diseases, stimulating acute and chronic inflammation, liver damage and fibrogenesis; it triggers endoplasmic reticulum (ER) stress response. The aim of our work was to investigate the activation of ER stress pathway after ectopic HBV envelope proteins expression, in liver cancer cells, and the role exerted by CB receptors. PCR, immunofluorescence and western blotting showed that exogenous LHBs and MHBs induce a clear ER stress response in Huh-7 cells expressing CB1 receptor. Up-regulation of the chaperone BiP/GRP78 (Binding Immunoglobulin Protein/Glucose-Regulated Protein 78) and of the transcription factor CHOP/GADD153 (C/EBP Homologous Protein/Growth Arrest and DNA Damage inducible gene 153), phosphorylation of PERK (PKR-like ER Kinase) and eIF2α (Eukaryotic Initiation Factor 2α) and splicing of XBP1 (X-box binding protein 1) was observed. CB1-/- HepG2 cells did not show any ER stress activation. Inhibition of CB1 receptor counteracted BiP expression in transfected Huh-7 and in HBV+ PLC/PRF/5 cells; whereas no effect was observed in HBV- HLF cells. These results suggest that HBV envelope proteins are able to induce the ER stress pathway. CB1 expression is directly correlated with ER stress function. Further investigations are needed to clarify the involvement of cannabinoid in HCC progression after HBV infection.”
Cannabinoid pharmacology in cancer research: A new hope for cancer patients?
“Cannabinoids have been used for many centuries to ease pain and in the past decade, the endocannabinoid system has been implicated in a number of pathophysiological conditions, such as mood and anxiety disorders, movement disorders such as Parkinson’s and Huntington’s disease, neuropathic pain, multiple sclerosis, spinal cord injury, atherosclerosis, myocardial infarction, stroke, hypertension, glaucoma, obesity, and osteoporosis.
Several studies have demonstrated that cannabinoids also have anti-cancer activity and as cannabinoids are usually well tolerated and do not produce the typical toxic effects of conventional chemotherapies, there is considerable merit in the development of cannabinoids as potential anticancer therapies.
Whilst the presence of psychoactive effects of cannabinoids could prevent any progress in this field, recent studies have shown the value of the non-psychoactive components of cannabinoids in activating apoptotic pathways, inducing anti-proliferative and anti-angiogenic effects.
The aforementioned effects are suggested to be through pathways such as ERK, Akt, mitogen-activated protein kinase (MAPK) pathways, phosphoinositide 3-kinase (PI3K) pathways and hypoxia inducible factor 1 (HIF1), all of which are important contributors to the hallmarks of cancer.
Many important questions still remain unanswered or are poorly addressed thus necessitating further research at basic pre-clinical and clinical levels. In this review, we address these issues with a view to identifying the key challenges that future research needs to address.”
Ligands for cannabinoid receptors, promising anticancer agents.
“Cannabinoid compounds are unique to cannabis and provide some interesting biological properties.
These compounds along with endocannabinoids, a group of neuromodulator compounds in the body especially in brain, express their effects by activation of G-protein-coupled cannabinoid receptors, CB1 and CB2.
There are several physiological properties attributed to the endocannabinoids including pain relief, enhancement of appetite, blood pressure lowering during shock, embryonic development, and blocking of working memory.
On the other hand, activation of endocannabinoid system may be suppresses evolution and progression of several types of cancer.
According to the results of recent studies, CB receptors are over-expressed in cancer cell lines and application of multiple cannabinoid or cannabis-derived compounds reduce tumor size through decrease of cell proliferation or induction of cell cycle arrest and apoptosis along with desirable effect on decrease of tumor-evoked pain.
Therefore, modulation of endocannabinoid system by inhibition of fatty acid amide hydrolase (FAAH), the enzyme, which metabolized endocannabinoids, or application of multiple cannabinoid or cannabis-derived compounds, may be appropriate for the treatment of several cancer subtypes. This review focuses on how cannabinoid affect different types of cancers.”
Liver’s cannabinoid receptors could be targeted to combat liver cancer in some patients
“A new study reveals that the liver’s cannabinoid receptors could be targeted to fight liver cancer in some patients; and it offers a way to predict what treatments have the best chance of working.
The body’s own marijuana-like substances, — called endocannabinoids — are known to increase the biosynthesis of fatty acids in the liver by activating cannabinoid type 1 receptors (CB1). CB1 receptors can be found in the brain, lungs, liver and kidney, and they are involved in a number of physiological processes, including mood, appetite, pain sensation and memory.
The study found that the expression of these receptors increased in cancerous liver samples, when compared with cancer-free samples. This suggests that drugs that block CB1 receptors may be effective against HCC.
“Although such drugs were found to cause unwanted psychiatric side effects, non brain-penetrant CB1 receptor antagonists devoid of such side effects — but retaining therapeutic efficacy via peripheral CB1 receptors — are currently being developed,” says study co-author George Kunos, scientific director at the U.S. National Institute on Alcohol Abuse and Alcoholism (NIAAA).”
Cannabinoid WIN55, 212-2 induces cell cycle arrest and inhibits the proliferation and migration of human BEL7402 hepatocellular carcinoma cells.
“Hepatocellular carcinoma (HCC) is the leading cause of cancer-associated mortality worldwide; however, only limited therapeutic treatments are currently available.
The present study aimed to investigate the effects of cannabinoids as novel therapeutic targets in HCC…
These results suggested that cannabinoid receptor agonists, including WIN, may be considered as novel therapeutics for the treatment of HCC.”
http://www.ncbi.nlm.nih.gov/pubmed/26500101
http://www.thctotalhealthcare.com/category/hepatocellular-carcinoma-hcc/
The dual effects of delta(9)-tetrahydrocannabinol on cholangiocarcinoma cells: anti-invasion activity at low concentration and apoptosis induction at high concentration.
“Currently, only gemcitabine plus platinum demonstrates the considerable activity for cholangiocarcinoma.
The anticancer effect of Delta (9)-tetrahydrocannabinol (THC), the principal active component of cannabinoids has been demonstrated in various kinds of cancers.
We therefore evaluate the antitumor effects of THC on cholangiocarcinoma cells.
Both cholangiocarcinoma cell lines and surgical specimens from cholangiocarcinoma patients expressed cannabinoid receptors.
THC inhibited cell proliferation, migration and invasion, and induced cell apoptosis.
THC also decreased actin polymerization and reduced tumor cell survival in anoikis assay. pMEK1/2 and pAkt demonstrated the lower extent than untreated cells.
Consequently, THC is potentially used to retard cholangiocarcinoma cell growth and metastasis.” http://www.ncbi.nlm.nih.gov/pubmed/19916793
“Cholangiocarcinoma is an epithelial cell malignancy arising from varying locations within the biliary tree showing markers of cholangiocyte differentiation. The most contemporary classification based on anatomical location includes intrahepatic, perihilar, and distal cholangiocarcinoma… Understanding of cholangiocarcinoma biology, the oncogenic landscape of this disease, and its complex interaction with the tumour microenvironment could lead to optimum therapies with improvement in patient survival… Hopefully, personalised or precision medicine is in the near future for the treatment of cholangiocarcinoma” http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4069226/
“Cholangiocarcinomas (bile duct cancers) are a heterogeneous group of malignancies arising from the epithelial cells of the intrahepatic, perihilar and extrahepatic bile ducts.” http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3731530/
“Cholangiocarcinoma (CC) is the second most common primary hepatic malignancy after hepatocellular cancer. CC accounts for approximately 10%-25% of all hepatobiliary malignancies. CC is a rare malignancy in Western countries, but more common in Asia. There are several established risk factors for CC, including parasitic infections, primary sclerosing cholangitis, biliary-duct cysts, hepatolithiasis, and toxins. Other less-established potential risk factors include inflammatory bowel disease, hepatitis C virus, hepatitis B virus, cirrhosis, diabetes, obesity, alcohol drinking, tobacco smoking, and host genetic polymorphisms.” http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3125451/
“Cholangiocarcinoma is a highly malignant cancer of the biliary tract with a poor prognosis, which often arises from conditions causing long-term inflammation, injury, and reparative biliary epithelial cell proliferation. Several conditions are known to be major risk factors for cancer in the biliary tract or gallbladder, including primary sclerosing cholangitis, liver fluke infection, pancreaticobiliary maljunction, and chemical exposure in proof-printing workers.” http://www.ncbi.nlm.nih.gov/pubmed/24895231
http://www.thctotalhealthcare.com/category/cholangiocarcinoma/