The levels of the endocannabinoid receptor CB2 and its ligand 2-arachidonoylglycerol are elevated in endometrial carcinoma

The clinical and pathological significance of increased expression of the cannabinoid receptors CB-1R and CB-2R in patients with papillary thyroid carcinomas compared to benign thyroid lesions

INTRODUCTION

Papillary thyroid carcinoma is the most common malignancy of the endocrine system. Most papillary thyroid carcinoma patients enjoy excellent outcomes. However, in patients with biologically aggressive features, additional prognostic and predictive data may aid disease management. Dysregulation of the endocannabinoid system including the cannabinoid receptors 1 and 2 (CB-1R and CB-2R) during carcinogenesis has been extensively studied over the last few decades. The aim of this study was to evaluate immunohistochemically the expression levels of both receptors in patients with papillary thyroid carcinoma and benign diseases, and to compare these rates and the histopathologically and clinically prognostic features.

METHODS

The pathological materials and clinical data of 100 patients with papillary thyroid carcinoma and 40 with benign diseases were retrospectively re-evaluated. All tissues were immunohistochemically stained for CB-1R and CB-2R. The expression levels of CB-1R and CB-2R in papillary thyroid carcinomas, and benign lesions were recorded and compared with the pathological and clinical features.

RESULTS

The expression levels of both receptors were significantly higher in papillary thyroid carcinoma patients than in those with benign conditions (P = 0.001). CB-1R expression correlated with both extrathyroidal extension (P = 0.022) and capsular invasion (P = 0.001). CB-2R expression was associated with the risk group of the American Thyroid Association stratification system (P = 0.004).

CONCLUSION

Our study suggests that increased cannabinoid receptor expression contributes to thyroid carcinogenesis. The CB-2R expression level could provide additional information aiding risk management. Furthermore, the CB-1R and CB-2R antibodies might increase the accuracy of papillary thyroid carcinoma diagnosis when combined with the papillary thyroid carcinoma biomarkers assayed after fine-needle aspiration of neoplastic cells.

Identification of Potentially Novel Molecular Targets of Endometrial Cancer Using a Non-Biased Proteomic Approach

The present study was aimed at identifying novel proteins in endometrial cancer (EC), employing proteomic analysis of tissues obtained after surgery. A differential MS-based proteomic analysis was conducted from whole tissues dissected from biopsies from post-menopausal women, histologically confirmed as endometrial cancer (two endometrioid and two serous; n = 4) or normal atrophic endometrium (n = 4), providing 888 differentially expressed proteins with 246 of these previously documented elsewhere as expressed in EC and 372 proteins not previously demonstrated to be expressed in EC but associated with other types of cancer. Additionally, 33 proteins not recorded previously in PubMed as being expressed in any forms of cancer were also identified, with only 26 of these proteins having a publication associated with their expression patterns or putative functions. The putative functions of the 26 proteins (GRN, APP, HEXA, CST3, CAD, QARS, SIAE, WARS, MYH8, CLTB, GOLIM4, SCARB2, BOD1L1, C14orf142, C9orf142, CCDC13, CNPY4, FAM169A, HN1L, PIGT, PLCL1, PMFBP1, SARS2, SCPEP1, SLC25A24 and ZC3H4) in other tissues point towards and provide a basis for further investigation of these previously unrecognised novel EC proteins. The developmental biology, disease, extracellular matrix, homeostatic, immune, metabolic (both RNA and protein), programmed cell death, signal transduction, molecular transport, transcriptional networks and as yet uncharacterised pathways indicate that these proteins are potentially involved in endometrial carcinogenesis and thus may be important in EC diagnosis, prognostication and treatment and thus are worthy of further investigation.

Diacylglycerol lipase alpha promotes hepatocellular carcinoma progression and induces lenvatinib resistance by enhancing YAP activity

As an important hydrolytic enzyme that yields 2-AG and free fatty acids, diacylglycerol lipase alpha (DAGLA) is involved in exacerbating malignant phenotypes and cancer progression, but the role of the DAGLA/2-AG axis in HCC progression remains unclear. Here, we found that the upregulation of components of the DAGLA/2-AG axis in HCC samples is correlated with tumour stage and patient prognosis. In vitro and in vivo experiments demonstrated that the DAGLA/2-AG axis promoted HCC progression by regulating cell proliferation, invasion and metastasis. Mechanistically, the DAGLA/2AG axis significantly inhibited LATS1 and YAP phosphorylation, promoted YAP nuclear translocation and activity, and ultimately led to TEAD2 upregulation and increased PHLDA2 expression, which could be enhanced by DAGLA/2AG-induced activation of the PI3K/AKT pathway. More importantly, DAGLA induced resistance to lenvatinib therapy during HCC treatment. Our study demonstrates that inhibiting the DAGLA/2-AG axis could be a novel therapeutic strategy to inhibit HCC progression and enhance the therapeutic effects of TKIs, which warrant further clinical studies.

An integrated approach of network pharmacology, molecular docking, and experimental verification uncovers kaempferol as the effective modulator of HSD17B1 for treatment of endometrial cancer

BACKGROUND

Endometrial cancer (EC) is one of the most common gynecological malignancies globally, and the development of innovative, effective drugs against EC remains a key issue. Phytoestrogen kaempferol exhibits anti-cancer effects, but the action mechanisms are still unclear.

METHOD

MTT assays, colony-forming assays, flow cytometry, scratch healing, and transwell assays were used to evaluate the proliferation, apoptosis, cell cycle, migration, and invasion of both ER-subtype EC cells. Xenograft experiments were used to assess the effects of kaempferol inhibition on tumor growth. Next-generation RNA sequencing was used to compare the gene expression levels in vehicle-treated versus kaempferol-treated Ishikawa and HEC-1-A cells. A network pharmacology and molecular docking technique were applied to identify the anti-cancer mechanism of kaempferol, including the building of target-pathway network. GO analysis and KEGG pathway enrichment analysis were used to identify cancer-related targets. Finally, the study validated the mRNA and protein expression using real-time quantitative PCR, western blotting, and immunohistochemical analysis.

RESULTS

Kaempferol was found to suppress the proliferation, promote apoptosis, and limit the tumor-forming, scratch healing, invasion, and migration capacities of EC cells. Kaempferol inhibited tumor growth and promotes apoptosis in a human endometrial cancer xenograft mouse model. No significant toxicity of kaempferol was found in human monocytes and normal cell lines at non-cytotoxic concentrations. No adverse effects or significant changes in body weight or organ coefficients were observed in 3-7 weeks' kaempferol-treated animals. The RNA sequencing, network pharmacology, and molecular docking approaches identified the overall survival-related differentially expressed gene HSD17B1. Interestingly, kaempferol upregulated HSD17B1 expression and sensitivity in ER-negative EC cells. Kaempferol differentially regulated PPARG expression in EC cells of different ER subtypes, independent of its effect on ESR1. HSD17B1 and HSD17B1-associated genes, such as ESR1, ESRRA, PPARG, AKT1, and AKR1C1\2\3, were involved in several estrogen metabolism pathways, such as steroid binding, 17-beta-hydroxysteroid dehydrogenase (NADP+) activity, steroid hormone biosynthesis, and regulation of hormone levels. The molecular basis of the effects of kaempferol treatment was evaluated.

CONCLUSIONS

Kaempferol is a novel therapeutic candidate for EC via HSD17B1-related estrogen metabolism pathways. These results provide new insights into the efficiency of the medical translation of phytoestrogens.

Cannabinoids as Prospective Anti-Cancer Drugs: Mechanism of Action in Healthy and Cancer Cells

Endogenous and exogenous cannabinoids modulate many physiological and pathological processes by binding classical cannabinoid receptors 1 (CB1) or 2 (CB2) or non-cannabinoid receptors. Cannabinoids are known to exert antiproliferative, apoptotic, anti-migratory and anti-invasive effect on cancer cells by inducing or inhibiting various signaling cascades. In this chapter, we specifically emphasize the latest research works about the alterations in endocannabinoid system (ECS) components in malignancies and cancer cell proliferation, migration, invasion, angiogenesis, autophagy, and death by cannabinoid administration, emphasizing their mechanism of action, and give a future perspective for clinical use.

Inhibition of diacylglycerol lipase β modulates lipid and endocannabinoid levels in the ex vivo human placenta

INTRODUCTION

Lipids and fatty acids are key components in metabolic processes of the human placenta, thereby contributing to the development of the fetus. Placental dyslipidemia and aberrant activity of lipases have been linked to diverse pregnancy associated complications, such as preeclampsia and preterm birth. The serine hydrolases, diacylglycerol lipase α and β (DAGLα, DAGLβ) catalyze the degradation of diacylglycerols, leading to the formation of monoacylglycerols (MAG), including one main endocannabinoid 2-arachidonoylglycerol (2-AG). The major role of DAGL in the biosynthesis of 2-AG is evident from various studies in mice but has not been investigated in the human placenta. Here, we report the use of the small molecule inhibitor DH376, in combination with the ex vivo placental perfusion system, activity-based protein profiling (ABPP) and lipidomics, to determine the impact of acute DAGL inhibition on placental lipid networks.

METHODS

DAGLα and DAGLβ mRNA expression was detected by RT-qPCR and in situ hybridization in term placentas. Immunohistochemistry staining for CK7, CD163 and VWF was applied to localize DAGLβ transcripts to different cell types of the placenta. DAGLβ activity was determined by in- gel and MS-based activity-based protein profiling (ABPP) and validated by addition of the enzyme inhibitors LEI-105 and DH376. Enzyme kinetics were measured by EnzChek™ lipase substrate assay. Ex vivo placental perfusion experiments were performed +/- DH376 [1 µM] and changes in tissue lipid and fatty acid profiles were measured by LC-MS. Additionally, free fatty acid levels of the maternal and fetal circulations were determined.

RESULTS

We demonstrate that mRNA expression of DAGLβ prevails in placental tissue, compared to DAGLα (p ≤ 0.0001) and that DAGLβ is mainly located to CK7 positive trophoblasts (p ≤ 0.0001). Although few DAGLα transcripts were identified, no active enzyme was detected applying in-gel or MS-based ABPP, which underlined that DAGLβ is the principal DAGL in the placenta. DAGLβ dependent substrate hydrolysis in placental membrane lysates was determined by the application of LEI-105 and DH376. Ex vivo pharmacological inhibition of DAGLβ by DH376 led to reduced MAG tissue levels (p ≤ 0.01), including 2-AG (p≤0.0001). We further provide an activity landscape of serine hydrolases, showing a broad spectrum of metabolically active enzymes in the human placenta.

DISCUSSION

Our results emphasize the role of DAGLβ activity in the human placenta by determining the biosynthesis of 2-AG. Thus, this study highlights the special importance of intra-cellular lipases in lipid network regulation. Together, the activity of these specific enzymes may contribute to the lipid signaling at the maternal-fetal interface, with implications for function of the placenta in normal and compromised pregnancies.

Phytocannabinoid Compositions from Cannabis Act Synergistically with PARP1 Inhibitor against Ovarian Cancer Cells In Vitro and Affect the Wnt Signaling Pathway

Ovarian cancer (OC) is the single most lethal gynecologic malignancy. Cannabis sativa is used to treat various medical conditions, and is cytotoxic to a variety of cancer types. We sought to examine the effectiveness of different combinations of cannabis compounds against OC. Cytotoxic activity was determined by XTT assay on HTB75 and HTB161 cell lines. Apoptosis was determined by flow cytometry. Gene expression was determined by quantitative PCR and protein localization by confocal microscopy. The two most active fractions, F5 and F7, from a high Δ9-tetrahydrocannabinol (THC) cannabis strain extract, and their standard mix (SM), showed cytotoxic activity against OC cells and induced cell apoptosis. The most effective phytocannabinoid combination was THC+cannabichromene (CBC)+cannabigerol (CBG). These fractions acted in synergy with niraparib, a PARP inhibitor, and were ~50-fold more cytotoxic to OC cells than to normal keratinocytes. The F7 and/or niraparib treatments altered Wnt pathway-related gene expression, epithelial-mesenchymal transition (EMT) phenotype and β-catenin cellular localization. The niraparib+F7 treatment was also effective on an OC patient's cells. Given the fact that combinations of cannabis compounds and niraparib act in synergy and alter the Wnt signaling pathway, these phytocannabinoids should be examined as effective OC treatments in further pre-clinical studies and clinical trials.

Use of Cannabis and Cannabinoids for Treatment of Cancer

The endocannabinoid system (ECS) is an ancient homeostasis mechanism operating from embryonic stages to adulthood. It controls the growth and development of many cells and cell lineages. Dysregulation of the components of the ECS may result in uncontrolled proliferation, adhesion, invasion, inhibition of apoptosis and increased vascularization, leading to the development of various malignancies. Cancer is the disease of uncontrolled cell division. In this review, we will discuss whether the changes to the ECS are a cause or a consequence of malignization and whether different tissues react differently to changes in the ECS. We will discuss the potential use of cannabinoids for treatment of cancer, focusing on primary outcome/care-tumor shrinkage and eradication, as well as secondary outcome/palliative care-improvement of life quality, including pain, appetite, sleep, and many more factors. Finally, we will complete this review with the chapter on sex- and gender-specific differences in ECS and response to cannabinoids, and equality of the access to treatments with cannabinoids.

Serine Hydrolases in Lipid Homeostasis of the Placenta-Targets for Placental Function?

The metabolic state of pregnant women and their unborn children changes throughout pregnancy and adapts to the specific needs of each gestational week. These adaptions are accomplished by the actions of enzymes, which regulate the occurrence of their endogenous substrates and products in all three compartments: mother, placenta and the unborn. These enzymes determine bioactive lipid signaling, supply, and storage through the generation or degradation of lipids and fatty acids, respectively. This review focuses on the role of lipid-metabolizing serine hydrolases during normal pregnancy and in pregnancy-associated pathologies, such as preeclampsia, gestational diabetes mellitus, or preterm birth. The biochemical properties of each class of lipid hydrolases are presented, with special emphasis on their role in placental function or dysfunction. While, during a normal pregnancy, an appropriate tonus of bioactive lipids prevails, dysregulation and aberrant signaling occur in diseased states. A better understanding of the dynamics of serine hydrolases across gestation and their involvement in placental lipid homeostasis under physiological and pathophysiological conditions will help to identify new targets for placental function in the future.

Metabolic Alterations in Sputum and Exhaled Breath Condensate of Early Stage Non-Small Cell Lung Cancer Patients After Surgical Resection: A Pilot Study

Every year, close to two million people world-wide are diagnosed with and die of lung cancer. Most patients present with advanced-stage cancer with limited curative options and poor prognosis. Diagnosis of lung cancer at an early stage provides the best chance for a cure. Low- dose CT screening of the chest in the high-risk population is the current standard of care for early detection of lung cancer. However, CT screening is invasive due to radiation exposure and carries the risk of unnecessary biopsies in non-cancerous tumors. In this pilot study, we present metabolic alterations observed in sputum and breath condensate of the same population of early- stage non-small cell lung cancer (NSCLC) patients cancer before and after surgical resection (SR), which could serve as noninvasive diagnostic tool. Exhaled breath condensate (EBC) (n=35) and sputum (n=15) were collected from early-stage non-small cell lung cancer (NSCLC) patients before and after SR. Median number of days for EBC and sputum collection before and after SR were 7 and 42; and 7 and 36 respectively Nuclear magnetic resonance (NMR) and liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) were used to analyze the metabolic profile of the collected samples. A total of 26 metabolites with significant alteration post SR were identified, of which 14 (54%) were lipids and 12 constituted nine different chemical metabolite classes. Eighteen metabolites (69%) were significantly upregulated and 8 (31%) were downregulated. Median fold change for all the up- and downregulated metabolites (LC-QTOF-MS) were 10 and 8, respectively. Median fold change (MFC) in concentration of all the up- and downregulated metabolites (NMR) were 0.04 and 0.27, respectively. Furthermore, glucose (median fold change, 0.01, p=0.037), adenosine monophosphate (13 log fold, p=0.0037) and N1, N12- diacetylspermine (8 log fold p=0.011) sputum levels were significantly increased post-SR. These identified sputa and EBC indices of altered metabolism could serve as basis for further exploration of biomarkers for early detection of lung cancer, treatment response, and targets for drug discovery. Validation of these promising results by larger clinical studies is warranted.

The Endocannabinoid System as a Pharmacological Target for New Cancer Therapies

Simple Summary

Cannabinoids have been shown to suppress tumour cell proliferation, tumour invasion, metastasis, angiogenesis, chemoresistance and epithelial-mesenchymal transition and to induce tumour cell apoptosis, autophagy and immune response. This review focuses on the current status of investigations on the impact of inhibitors of endocannabinoid-degrading enzymes on tumour growth and spread in preclinical oncology research.

Abstract

Despite the long history of cannabinoid use for medicinal and ritual purposes, an endogenous system of cannabinoid-controlled receptors, as well as their ligands and the enzymes that synthesise and degrade them, was only discovered in the 1990s. Since then, the endocannabinoid system has attracted widespread scientific interest regarding new pharmacological targets in cancer treatment among other reasons. Meanwhile, extensive preclinical studies have shown that cannabinoids have an inhibitory effect on tumour cell proliferation, tumour invasion, metastasis, angiogenesis, chemoresistance and epithelial-mesenchymal transition (EMT) and induce tumour cell apoptosis and autophagy as well as immune response. Appropriate cannabinoid compounds could moreover be useful for cancer patients as potential combination partners with other chemotherapeutic agents to increase their efficacy while reducing unwanted side effects. In addition to the direct activation of cannabinoid receptors through the exogenous application of corresponding agonists, another strategy is to activate these receptors by increasing the endocannabinoid levels at the corresponding pathological hotspots. Indeed, a number of studies accordingly showed an inhibitory effect of blockers of the endocannabinoid-degrading enzymes fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) on tumour development and spread. This review summarises the relevant preclinical studies with FAAH and MAGL inhibitors compared to studies with cannabinoids and provides an overview of the regulation of the endocannabinoid system in cancer.

Monoacylglycerol lipase deficiency in the tumor microenvironment slows tumor growth in non-small cell lung cancer

Monoacylglycerol lipase (MGL) expressed in cancer cells influences cancer pathogenesis but the role of MGL in the tumor microenvironment (TME) is less known. Using a syngeneic tumor model with KP cells (KrasLSL-G12D/p53fl/fl; from mouse lung adenocarcinoma), we investigated whether TME-expressed MGL plays a role in tumor growth of non-small cell lung cancer (NSCLC). In sections of human and experimental NSCLC, MGL was found in tumor cells and various cells of the TME including macrophages and stromal cells. Mice treated with the MGL inhibitor JZL184 as well as MGL knock-out (KO) mice exhibited a lower tumor burden than the controls. The reduction in tumor growth was accompanied by an increased number of CD8+ T cells and eosinophils. Naïve CD8+ T cells showed a shift toward more effector cells in MGL KOs and an increased expression of granzyme-B and interferon-γ, indicative of enhanced tumoricidal activity. 2-arachidonoyl glycerol (2-AG) was increased in tumors of MGL KO mice, and dose-dependently induced differentiation and migration of CD8+ T cells as well as migration and activation of eosinophils in vitro. Our results suggest that next to cancer cell-derived MGL, TME cells expressing MGL are responsible for maintaining a pro-tumorigenic environment in tumors of NSCLC.

The major endocannabinoid anandamide (AEA) induces apoptosis of human granulosa cells

The endocannabinoid system (ECS) plays a crucial role in human reproduction. Changes in anandamide (AEA) levels affect reproductive events and has already been suggested as biomarker of reproductive potential of male and female gametes. Although cannabinoid-receptor 1 (CB1) was already identified in human granulosa cells (hGCs) the ECS was not characterized on granulosa cells line COV434 nor the effects of AEA on GCs viability and function depicted. Therefore, the aim of this study was to characterize the ECS elements and explore the effects of AEA on both COV434 and hGCs. Our results revealed that hGCs express the full enzymatic machinery responsible for AEA metabolism as well as cannabinoid receptors. In addition, AEA induced a reduction in both COV434 and hGCs viability in a concentration and time-dependent manner. Nevertheless, the effects of AEA in cell viability was independent of either CB1 or CB2 receptors. There was no ROS release in both cell models; however, AEA induced morphological changes, presenting chromatin condensation at 72 h, and variation on mitochondrial membrane potential. Moreover, AEA induced an increase in caspase -3/-7 activities in both cell models, but in hGCs there was also an increase in caspase 8 activity. This study supports the idea that ECS balance is crucial for folliculogenesis and oocyte quality as dysregulated AEA levels may compromise female fertility.

Expression of the putative cannabinoid receptor GPR55 is increased in endometrial carcinoma

Although the expression of the putative cannabinoid receptor GPR55 has been shown to be involved in the growth of various tumours and is increased in a number of cancers, its expression has not been examined in patients with endometrial cancer (EC). Quantitative RT-PCR (for mRNA levels) and immunohistochemistry (for protein levels) were used to measure GPR55 expression in patients with Type 1 and Type 2 EC and correlated against cannabinoid receptor (CB1 and CB2) protein levels using non-cancerous endometrium as the control tissue. The data indicated that GPR55 transcript and GPR55 protein levels were significantly (p < 0.002 and p < 0.0001, respectively) higher in EC tissues than in control tissues. The levels of immunoreactive GPR55 protein were correlated with GPR55 transcript levels, but not with the expression of CB1 receptor protein, and were inversely correlated with CB2 protein expression, which was significantly decreased. It can be concluded that GPR55 expression is elevated in women with EC, and thus could provide a potential novel biomarker and therapeutic target for this disease.

Therapeutic Attributes of Endocannabinoid System against Neuro-Inflammatory Autoimmune Disorders

In humans, various sites like cannabinoid receptors (CBR) having a binding affinity with cannabinoids are distributed on the surface of different cell types, where endocannabinoids (ECs) and derivatives of fatty acid can bind. The binding of these substance(s) triggers the activation of specific receptors required for various physiological functions, including pain sensation, memory, and appetite. The ECs and CBR perform multiple functions via the cannabinoid receptor 1 (CB1); cannabinoid receptor 2 (CB2), having a key effect in restraining neurotransmitters and the arrangement of cytokines. The role of cannabinoids in the immune system is illustrated because of their immunosuppressive characteristics. These characteristics include inhibition of leucocyte proliferation, T cells apoptosis, and induction of macrophages along with reduced pro-inflammatory cytokines secretion. The review seeks to discuss the functional relationship between the endocannabinoid system (ECS) and anti-tumor characteristics of cannabinoids in various cancers. The therapeutic potential of cannabinoids for cancer-both in vivo and in vitro clinical trials-has also been highlighted and reported to be effective in mice models in arthritis for the inflammation reduction, neuropathic pain, positive effect in multiple sclerosis and type-1 diabetes mellitus, and found beneficial for treating in various cancers. In human models, such studies are limited; thereby, further research is indispensable in this field to get a conclusive outcome. Therefore, in autoimmune disorders, therapeutic cannabinoids can serve as promising immunosuppressive and anti-fibrotic agents.

An Agathokakological Tale of Δ9-THC: Exploration of Possible Biological Targets

Δ⁹-Tetrahydrocannabinol (Δ⁹-THC), the active phytocannabinoid in cannabis, is virtually an adjunct to the endogenous endocannabinoid signaling system. By interacting with G-proteincoupled receptors CB1 and CB2, Δ⁹-THC affects peripheral and central circulation by lowering sympathetic activity, altering gene expression, cell proliferation, and differentiation, decreasing leukocyte migration, modulating neurotransmitter release, thereby modulating cardiovascular functioning, tumorigenesis, immune responses, behavioral and locomotory activities. Δ⁹-THC effectively suppresses chemotherapy-induced vomiting, retards malignant tumor growth, inhibits metastasis, and promotes apoptosis. Other mechanisms involved are targeting cell cycle at the G2-M phase in human breast cancer, downregulation of E2F transcription factor 1 (E2F1) in human glioblastoma multiforme, and stimulation of ER stress-induced autophagy. Δ⁹-THC also plays a role in ameliorating neuroinflammation, excitotoxicity, neuroplasticity, trauma, and stroke and is associated with reliving childhood epilepsy, brain trauma, and neurodegenerative diseases. Δ⁹-THC via CB1 receptors affects nociception, emotion, memory, and reduces neuronal excitability and excitotoxicity in epilepsy. It also increases renal blood flow, reduces intraocular pressure via a sympathetic pathway, and modulates hormonal release, thereby decreasing the reproductive function and increasing glucose metabolism. Versatile medical marijuana has stimulated abundant research demonstrating substantial therapeutic promise, suggesting the possibilities of first-in-class drugs in diverse therapeutic segments. This review represents the current pharmacological status of the phytocannabinoid, Δ⁹-THC, and synthetic analogs in cancer, cardiovascular, and neurodegenerative disorders.

Molecular Mechanism of Cannabinoids in Cancer Progression

Cannabinoids are a family of heterogeneous compounds that mostly interact with receptors eliciting several physiological effects both in the central and peripheral nervous systems and in peripheral organs. They exert anticancer action by modulating signaling pathways involved in cancer progression; furthermore, the effects induced by their use depend on both the type of tumor and their action on the components of the endocannabinoid system. This review will explore the mechanism of action of the cannabinoids in signaling pathways involved in cancer proliferation, neovascularisation, migration, invasion, metastasis, and tumor angiogenesis.

Functional Fine-Tuning of Metabolic Pathways by the Endocannabinoid System-Implications for Health and Disease

The endocannabinoid system (ECS) employs a huge network of molecules (receptors, ligands, and enzymatic machinery molecules) whose interactions with other cellular networks have still not been fully elucidated. Endogenous cannabinoids are molecules with the primary function of control of multiple metabolic pathways. Maintenance of tissue and cellular homeostasis by functional fine-tuning of essential metabolic pathways is one of the key characteristics of the ECS. It is implicated in a variety of physiological and pathological states and an attractive pharmacological target yet to reach its full potential. This review will focus on the involvement of ECS in glucose and lipid metabolism, food intake regulation, immune homeostasis, respiratory health, inflammation, cancer and other physiological and pathological states will be substantiated using freely available data from open-access databases, experimental data and literature review. Future directions should envision capturing its diversity and exploiting pharmacological options beyond the classical ECS suspects (exogenous cannabinoids and cannabinoid receptor monomers) as signaling through cannabinoid receptor heteromers offers new possibilities for different biochemical outcomes in the cell.

UXT antisense RNA 1 sever as a novel prognostic long non-coding RNA in early stage pancreatic ductal adenocarcinoma patients after receiving pancreaticoduodenectomy

Objective: The principal objective of this project was to investigate the prognostic value of UXT antisense RNA 1 (UXT-AS1) in pancreatic ductal adenocarcinoma (PDAC), as well as its biological function mechanisms and the screening of targeted drugs using The Cancer Genome Atlas (TCGA) PDAC genome-wide RNA sequencing (RNA-seq) dataset.

Methods: We used TCGA 112 early stage PDAC patients to screen the prognostic value of UXT-AS1. Biological functions and mechanisms of UXT-AS1 were investigated by co-expression analysis, differentially expressed genes (DEGs) and gene set enrichment analysis, while targeted drug screening was investigated by connectivity Map (CMap).

Results: By analyzing the dataset from TCGA cohort, we found that UXT-AS1 was significantly up-regulated in pancreatic cancer tissues. Multivariate survival analysis demonstrated that PDAC patients with high UXT-AS1 expression had an unfavourable prognosis (adjusted P=0.033, HR=1.830, 95%CI=1.051-3.188). Genome-wide co-expression analysis and gene set enrichment analysis suggested that UXT-AS1 may act as a pivotal part in PDAC by participating in nuclear factor kappa beta, regulation of tumor necrosis factor, cell adhesion, T cell receptor signaling pathway, and numerous immune-related biological processes and signaling pathways. Functional enrichment analysis of DEGs between high- and low-UXT-AS1 expression groups suggested that these DEGs were significant enriched in B cell receptor complex, response to drug chemical carcinogenesis and drug metabolism-cytochrome P450. CMap analysis revealed that quipazine and terazosin may be targeted drugs for UXT-AS1 in PDAC.

Conclusion: Our current study has identified UXT-AS1 as a novel biomarker for the prognosis of early stage PDAC. We also clarified its biological functional mechanisms and identified two targeted drugs of UXT-AS1 in PDAC.

The Complex Interplay between Endocannabinoid System and the Estrogen System in Central Nervous System and Periphery

The endocannabinoid system (ECS) is a lipid cell signaling system involved in the physiology and homeostasis of the brain and peripheral tissues. Synaptic plasticity, neuroendocrine functions, reproduction, and immune response among others all require the activity of functional ECS, with the onset of disease in case of ECS impairment. Estrogens, classically considered as female steroid hormones, regulate growth, differentiation, and many other functions in a broad range of target tissues and both sexes through the activation of nuclear and membrane estrogen receptors (ERs), which leads to genomic and non-genomic cell responses. Since ECS function overlaps or integrates with many other cell signaling systems, this review aims at updating the knowledge about the possible crosstalk between ECS and estrogen system (ES) at both central and peripheral level, with focuses on the central nervous system, reproduction, and cancer.

Therapeutic potential of cannabinoids in combination cancer therapy

Derivatives of the plant Cannabis sativa have been used for centuries for both medical and recreational purposes, as well as industrial. The first proof of its medicinal use comes from ancient China, although there is evidence of its earlier utilization in Europe and Asia. In the 19th century, European practitioners started to employ cannabis extracts to treat tetanus, convulsions, and mental diseases and, in 1851, cannabis made its appearance in the Pharmacopoeia of the United States as an analgesic, hypnotic and anticonvulsant. It was only in 1937 that the Marijuana Tax Act prohibited the use of this drug in the USA. The general term Cannabis is commonly used by the scientific and scholar community to indicate derivatives of the plant Cannabis sativa. The word cannabinoid is a term describing chemical compounds that are either derivate of Cannabis (phytocannabinoids) or artificial analogues (synthetic) or are produced endogenously by the body (endocannabinoids). A more casual term "marijuana" or "weed", a compound derived from dried Cannabis flower tops and leaves, has progressively superseded the term cannabis when referred to its recreational use. The 2018 World health organisation (WHO) data suggest that nearly 2.5% of the global population (147 million) uses marijuana and some countries, such as Canada and Uruguay, have already legalised it. Due to its controversial history, the medicinal use of cannabinoids has always been a centre of debate. The isolation and characterisation of Δ⁹ tetrahydrocannabinol (THC), the major psychoactive component of cannabis and the detection of two human cannabinoid receptor (CBRs) molecules renewed interest in the medical use of cannabinoids, boosting research and commercial heed in this sector. Some cannabinoid-based drugs have been approved as medications, mainly as antiemetic, antianorexic, anti-seizure remedies and in cancer and multiple sclerosis patients' palliative care. Nevertheless, due to the stigma commonly associated with these compounds, cannabinoids' potential in the treatment of conditions such as cancer is still largely unknown and therefore underestimated.

(Endo)Cannabinoids and Gynaecological Cancers

Gynaecological cancers can be primary neoplasms, originating either from the reproductive tract or the products of conception, or secondary neoplasms, representative of metastatic disease. For some of these cancers, the exact causes are unknown; however, it is recognised that the precise aetiopathogeneses for most are multifactorial and include exogenous (such as diet) and endogenous factors (such as genetic predisposition), which mutually interact in a complex manner. One factor that has been recognised to be involved in the pathogenesis and progression of gynaecological cancers is the endocannabinoid system (ECS). The ECS consists of endocannabinoids (bioactive lipids), their receptors, and metabolic enzymes responsible for their synthesis and degradation. In this review, the impact of plant-derived (Cannabis species) cannabinoids and endocannabinoids on gynaecological cancers will be discussed within the context of the complexity of the proteins that bind, transport, and metabolise these compounds in reproductive and other tissues. In particular, the potential of endocannabinoids, their receptors, and metabolic enzymes as biomarkers of specific cancers, such as those of the endometrium, will be addressed. Additionally, the therapeutic potential of targeting selected elements of the ECS as new action points for the development of innovative drugs will be presented.

Endometrial cancer: a genetic point of view

BACKGROUND

Endometrial cancer is the fourth most frequent gynecological cancer and the most frequent type of uterine cancer. There is an increase in the incidence and mortality of uterine cancers in the past few decades, and there are no well-established screening programs for endometrial cancer currently. Most endometrial cancers arise through the interplay of familial, genetic, and lifestyle factors. Although a number of genetic factors modify endometrial cancer susceptibility, they are not of standard use in the clinical assessment of prognosis. We conducted a comprehensive systematic literature review to provide an overview of the relationship between genetic factors and risk for endometrial cancer.

METHODS

MEDLINE and EMBASE databases were searched for studies between January 2010 to March 2020 reporting the genes associated with endometrial cancer.

RESULTS

Through the selection process, we retrieved 186 studies comprising 329 genes identified using several molecular methodologies in all human chromosomes and in mitochondrial DNA. Endometrial cancer exhibits a molecular complexity and heterogeneity coherent with its clinical and histologic variability. Improved characterization of molecular alterations of each histological type provides relevant information about the prognosis and potential response to new therapies.

CONCLUSIONS

The current challenge is the integration of clinicopathologic and molecular factors to improve the diagnosis, prognosis, and treatment of endometrial cancer.

The Interplay between Cancer Biology and the Endocannabinoid System-Significance for Cancer Risk, Prognosis and Response to Treatment

The various components of the endocannabinoid system (ECS), such as the cannabinoid receptors (CBRs), cannabinoid ligands, and the signalling network behind it, are implicated in several tumour-related states, both as favourable and unfavourable factors. This review analyses the ECS's complex involvement in the susceptibility to cancer, prognosis, and response to treatment, focusing on its relationship with cancer biology in selected solid cancers (breast, gastrointestinal, gynaecological, prostate cancer, thoracic, thyroid, CNS tumours, and melanoma). Changes in the expression and activation of CBRs, as well as their ability to form distinct functional heteromers affect the cell's tumourigenic potential and their signalling properties, leading to pharmacologically different outcomes. Thus, the same ECS component can exert both protective and pathogenic effects in different tumour subtypes, which are often pathologically driven by different biological factors. The use of endogenous and exogenous cannabinoids as anti-cancer agents, and the range of effects they might induce (cell death, regulation of angiogenesis, and invasion or anticancer immunity), depend in great deal on the tumour type and the specific ECS component that they target. Although an attractive target, the use of ECS components in anti-cancer treatment is still interlinked with many legal and ethical issues that need to be considered.

The Cannabinoids Effect on Bone Formation and Bone Healing

PURPOSE OF REVIEW

Here, we overview the latest findings from studies investigating the skeletal endocannabinoid (EC) system and its involvement in bone formation and resorption.

RECENT FINDINGS

The endocannabinoid system consists of endogenous ligands, receptors, and enzymes. The main cannabinoids found in the cannabis plant are Δ⁹-tetrahydrocannabinol (THC) and cannabidiol (CBD). Cannabinoid receptors CB1 and CB2 are expressed in bone and regulate bone homeostasis in rodents and humans. CBD treatment was shown to enhance fracture healing in rats. Recent studies in mice indicate that strain, age, and sex differences dictate the skeletal outcome of the EC activation. CBD treatment was shown to enhance bone healing, but needs validation in clinical trials. While research shows that EC activity protects against bone loss, studies on CB1 and CB2 agonists in bone regeneration models are lacking. Whether modulating the EC system would affect bone repair remains therefore an open question worth investigating.

The Effects of Cannabidiol and Prognostic Role of TRPV2 in Human Endometrial Cancer

Several studies support, both in vitro and in vivo, the anti-cancer effects of cannabidiol (CBD), a transient receptor potential vanilloid 2 (TRPV2) ligand. TRPV2, often dysregulated in tumors, is associated with altered cell proliferation and aggressiveness. Endometrial cancer (EC) is historically divided in type I endometrioid EC and type II non-endometrioid EC, associated with poor prognosis. Treatment options with chemotherapy and combinations with radiation showed only limited efficacy. Since no data are reported concerning TRPV2 expression as well as CBD potential effects in EC, the aim of this study was to evaluate the expression of TRPV2 in biopsies and cell lines as well as the effects of CBD in in vitro models. Overall survival (OS), progression-free survival (PFS), cell viability, migration, and chemo-resistance have been evaluated. Results show that TRPV2 expression increased with the malignancy of the cancer tissue and correlated with shorter PFS (p = 0.0224). Moreover, in vitro TRPV2 over-expression in Ishikawa cell line increased migratory ability and response to cisplatin. CBD reduced cell viability, activating predominantly apoptosis in type I cells and autophagy in mixed type EC cells. The CBD improved chemotherapeutic drugs cytotoxic effects, enhanced by TRPV2 over-expression. Hence, TRPV2 could be considered as a marker for optimizing the therapy and CBD might be a useful therapeutic option as adjuvant therapy.

The fundamental role of the endocannabinoid system in endometrium and placenta: implications in pathophysiological aspects of uterine and pregnancy disorders

BACKGROUND

The endocannabinoid system (ECS) consists of the cannabinoid receptors CB1 and CB2, the main endocannabinoids anandamide (AEA) and 2-arachidonoylglycerol (2-AG) and their metabolic enzymes N-acylphosphatidylethanolamine-specific phospholipase D, fatty acid amide hydrolase, diacylglycerol lipase and monoacylglycerol lipase. This system is involved in the modulation of essential physiological processes. Its role in the reproductive system has become significantly important in recent years, given its major role in events such as gametogenesis, decidualisation, implantation and placentation.

OBJECTIVE AND RATIONALE

In this paper, we review the literature and summarize the role of the ECS elements in reproduction and their potential as early markers for diagnosis of reproductive disorders or as pharmacological targets for treatment.

SEARCH METHODS

Original research and review papers published from 1964 to June 2019 were selected in terms of relevance, reliability and quality by searching PubMed, MEDLINE and Web of Science, using the following search terms: endocannabinoid system and endometriosis; endocannabinoid system and ectopic pregnancy; endocannabinoid system and miscarriage; endocannabinoid system and pre-eclampsia; endocannabinoid system and endometrial cancer; endocannabinoid system and reproduction; endocannabinoid, endometrium; placenta; N-acylethanolamines; anandamide; 2-arachidonoylglycerol; and cannabinoids.

OUTCOMES

This review demonstrates relevant information concerning ECS alterations in endometriosis, ectopic pregnancy, miscarriage, pre-eclampsia and endometrial cancer. We highlight the importance of the endocannabinoids in endometrial and placental physiology and pathophysiology, from studies in vitro and in vivo and in clinical observations. The most studied of the endogenous cannabinoids is AEA. The levels of AEA were increased in plasma of patients with endometriosis and miscarriage, as well as in the fallopian tube of women with ectopic pregnancy and in endometrial biopsies of endometrial cancer. Changes in the pattern of expression of the cannabinoid receptor CB1 were also observed in endometrial biopsies of endometriosis, fallopian tube and decidua of patients with ectopic pregnancy and pre-eclamptic placenta. Moreover, alterations in CB2 expression have been reported in association with endometrial cancer. In general, studies on the cannabinoid signalling through CB2 and on the biological activities of the other major endocannabinoid, namely 2-AG, as well as its metabolic enzymes are scarce and avidly required.

WIDER IMPLICATIONS

The pathophysiological mechanisms involved in the described endometrial and placental pathologies are still unclear and lack the means for an early diagnosis. Based on current evidence, though alterations in ECS are demonstrated at tissue level, it is difficult to associate plasmatic changes in AEA with specific endometrial and placental diseases. Thus, pairing alterations in AEA levels with 2-AG and/or other endocannabinoid-like molecules may provide more accurate and early diagnoses. In addition, patients may benefit from new therapies that target the ECS and endocannabinoid signalling.

Cannabinoid Receptor Type 2: A Possible Target in SARS-CoV-2 (CoV-19) Infection?

In late December 2019, a novel coronavirus (SARS-CoV-2 or CoV-19) appeared in Wuhan, China, causing a global pandemic. SARS-CoV-2 causes mild to severe respiratory tract inflammation, often developing into lung fibrosis with thrombosis in pulmonary small vessels and causing even death. COronaVIrus Disease (COVID-19) patients manifest exacerbated inflammatory and immune responses, cytokine storm, prevalence of pro-inflammatory M1 macrophages and increased levels of resident and circulating immune cells. Men show higher susceptibility to SARS-CoV-2 infection than women, likely due to estrogens production. The protective role of estrogens, as well as an immune-suppressive activity that limits the excessive inflammation, can be mediated by cannabinoid receptor type 2 (CB2). The role of this receptor in modulating inflammation and immune response is well documented in fact in several settings. The stimulation of CB2 receptors is known to limit the release of pro-inflammatory cytokines, shift the macrophage phenotype towards the anti-inflammatory M2 type and enhance the immune-modulating properties of mesenchymal stromal cells. For these reasons, we hypothesize that CB2 receptor can be a therapeutic target in COVID-19 pandemic emergency.

Selection of Endogenous Control Reference Genes for Studies on Type 1 or Type 2 Endometrial Cancer

A panel of 32 candidate reference genes was used to identify the most stable genes for gene normalisation in quantitative RT-PCR studies using endometrial biopsies obtained from women with endometrial cancer (type 1 or type 2) and without cancer (controls). RNA from the biopsies was isolated, examined for purity and quality, and then reverse transcribed into cDNA before being subjected to real-time qRT-PCR analysis in triplicate within the TaqMan gene Expression Assay kit. The most 'stable' endogenous control genes were then identified using the geNorm qbase + 2 and NormFinder software packages. PSMC4, PUM1 and IPO8 were identified as the best reference genes combination for type 1 endometrial cancer (grades 1, 2 and 3), whereas for type 2 endometrial cancer (serous and carcinosarcoma), UBC, MRPL19, PGK1 and PPIA were the best reference genes combination. We conclude that the use of these normaliser combinations should provide accurate interpretation of gene expression at the transcript level in endometrial cancer studies especially for types 1 and 2 cancers.

Metabolomics in endometrial cancer diagnosis: A systematic review

INTRODUCTION

Endometrial cancer (EC) is the most common gynecological malignancy in the developed world. The prognosis of EC strongly depends on tumor stage, hence the importance of improving diagnosis. Metabolomics has recently appeared as a promising test for a non-invasive diagnosis of several diseases. Nevertheless, no metabolic marker has been approved for use in the routine practice. We aimed to provide an overview of metabolomics findings in the diagnosis of EC.

MATERIAL AND METHODS

A systematic review was performed by searching eight electronic databases from their inception to October 2019 for studies assessing metabolomics in EC diagnosis. Extracted data included characteristics of patients and EC, serum concentration of metabolites in women with and without EC and its association with EC diagnosis, tumor behavior and pathological characteristics.

RESULTS

Six studies with 732 women (356 cases and 376 controls) were included. Several metabolites were found able to predict the presence of EC, tumor behavior (progression and recurrence) and pathological characteristics (histotype, myometrial invasion and lymph vascular space invasion).

CONCLUSIONS

Metabolomics might be suitable for a non-invasive diagnosis and screening of EC, offering the possibility to predict tumor behavior and pathological characteristics. Further studies are necessary to validate these results.

The (endo)cannabinoid signaling in female reproduction: What are the latest advances?

Cannabis extracts like marijuana have the highest consumption rate worldwide. Yet, their societal acceptance as recreational and therapeutic drugs could represent a serious hazard to female human reproduction, because cannabis ingredients [termed (phyto)cannabinoids] can perturb an endogenous system of lipid signals known as endocannabinoids. Accumulated evidence on animal models and humans has demonstrated a crucial role of these endogenous signals on different aspects of female reproduction, where they act through an ensamble of proteins that synthesize, transport, degrade and traffic them. Several reports have recently evidenced the potential role of endocannabinoids as biomarkers of female infertility for disease treatment and prevention, as well as their possible epigenetic effects on pregnancy. The purpose of this review is to provide an update of data collected in the last decade on the effects of cannabinoids and endocannabinoids on female reproductive events, from development and maturation of follicles and oocytes, to fertilization, oviductal transport, implantation and labor. In this context, a particular attention has been devoted to the ovary and the production of fertilizable oocytes, because recent studies have addressed this hot topic with conflicting results among species.

Identification of Novel Predictive Biomarkers for Endometrial Malignancies: N-Acylethanolamines

Objective: To identify new biochemical markers for endometrial cancer (EC). Recent evidence suggests that members of the endocannabinoid system (N-acylethanolamines) that bind to and activate receptors that are dysregulated in EC are involved in this tumour's biology. These observations suggest increased N-acylethanolamine levels in the tissue that might appear in plasma and could be used as disease biomarkers. Methods: N-arachidonoylethanolamine (anandamide, AEA) and the N-acylethanolamine substances, N-oleoylethanolamine (OEA), and N-palmitoylethanolamine (PEA) were quantified in plasma and endometrial tissue collected from 31 EC and seven atrophic controls using UHPLC-MS/MS. Receiver-operating characteristics (ROC) and logistic regression were used to determine diagnostic accuracy. Cannabinoid receptor 1 (CB1) and 2 (CB2) protein levels were determined by specific immunohistochemistry and histomorphometric analyses. Correlations between plasma and tissue levels of the three N-acylethanolamines and tissue levels of the three N-acylethanolamines and CB1 and CB2 receptor expression levels were determined using correlation analysis. Results: Plasma and tissue AEA and PEA levels were significantly (p < 0.05) higher in EC than controls whilst OEA levels were significantly elevated in type 1 EC tissues but not in plasma. There were significant positive correlations between plasma and tissue levels of AEA (R ² = 0.302, p = 0.008) and PEA (R ² = 0.182, p = 0.047), but not for OEA (R ² = 0.022, p = 0.506). The diagnostic accuracies for EC were: sensitivity of 53.3%, specificity of 100% for plasma AEA (>1.36 nM); sensitivity of 73.3%, specificity of 100% for plasma PEA (>27.5 nM); and sensitivity of 93.3%, specificity of 28.6% for plasma OEA (>4.97 nM). Logistic regression increased the area under the ROC curve (AUC) from 0.781 for AEA, 0.857 for PEA, and 0.543 for OEA to a combined AUC of 0.933 for EC diagnosis. Significant inverse correlations between tissue AEA (R ² = 0.343, p = 0.003) and PEA (R ² = 0.384, p < 0.0001) levels and CB1 expression were observed. No correlation between tissue levels of OEA and CB1 and tissue levels of any of the three N-acylethanolamines and CB2 protein expression were observed, except in the type 1 EC patients. Conclusion: Since plasma AEA and PEA are significantly elevated in patients with EC and a reflection of production by the endometrial tumour, then these lipids have the potential to be useful biomarkers for the early diagnosis of EC.

Cannabinoids in Gynecological Diseases

The endocannabinoid system (ECS) is a multifunctional homeostatic system involved in many physiological and pathological conditions. The ligands of the ECS are the endo-cannabinoids, whose actions are mimicked by exogenous cannabinoids, such as phytocannabinoids and synthetic cannabinoids. Responses to the ligands of the ECS are mediated by numerous receptors like the classical cannabinoid receptors (CB₁ and CB₂) as well as ECS-related receptors, e.g., G protein-coupled receptors 18 and 55 (GPR18 and GPR55), transient receptor potential ion channels, and nuclear peroxisome proliferator-activated receptors. The ECS regulates almost all levels of female reproduction, starting with oocyte production through to parturition. Dysregulation of the ECS is associated with the development of gynecological disorders from fertility disorders to cancer. Cannabinoids that act at the ECS as specific agonists or antagonists may potentially influence dysregulation and, therefore, represent new therapeutic options for the therapy of gynecological disorders.

Modulation of the Endocannabinoid System as a Potential Anticancer Strategy

Currently, the involvement of the endocannabinoid system in cancer development and possible options for a cancer-regressive effect of cannabinoids are controversially discussed. In recent decades, a number of preclinical studies have shown that cannabinoids have an anticarcinogenic potential. Therefore, especially against the background of several legal simplifications with regard to the clinical application of cannabinoid-based drugs, an extended basic knowledge about the complex network of the individual components of the endocannabinoid system is required. The canonical endocannabinoid system consists of the endocannabinoids N-arachidonoylethanolamine (anandamide) and 2-arachidonoylglycerol as well as the G_i/o protein-coupled transmembrane cannabinoid receptors CB₁ and CB₂. As a result of extensive studies on the broader effect of these factors, other fatty acid derivatives, transmembrane and intracellular receptors, enzymes and lipid transporters have been identified that contribute to the effect of endocannabinoids when defined in the broad sense as “extended endocannabinoid system.” Among these additional components, the endocannabinoid-degrading enzymes fatty acid amide hydrolase and monoacylglycerol lipase, lipid transport proteins of the fatty acid-binding protein family, additional cannabinoid-activated G protein-coupled receptors such as GPR55, members of the transient receptor family, and peroxisome proliferator-activated receptors were identified as targets for possible strategies to combat cancer progression. Other endocannabinoid-related fatty acids such as 2-arachidonoyl glyceryl ether, O-arachidonoylethanolamine, N-arachidonoyldopamine and oleic acid amide showed an effect via cannabinoid receptors, while other compounds such as endocannabinoid-like substances exert a permissive action on endocannabinoid effects and act via alternative intracellular target structures. This review gives an overview of the modulation of the extended endocannabinoid system using the example of anticancer cannabinoid effects, which have been described in detail in preclinical studies.

The Endocannabinoid/Endovanilloid System in Bone: From Osteoporosis to Osteosarcoma

Bone is a dynamic tissue, whose homeostasis is maintained by a fine balance between osteoclast (OC) and osteoblast (OB) activity. The endocannabinoid/endovanilloid (EC/EV) system’s receptors are the cannabinoid receptor type 1 (CB1), the cannabinoid receptor type 2 (CB2), and the transient receptor potential cation channel subfamily V member 1 (TRPV1). Their stimulation modulates bone formation and bone resorption. Bone diseases are very common worldwide. Osteoporosis is the principal cause of bone loss and it can be caused by several factors such as postmenopausal estrogen decrease, glucocorticoid (GC) treatments, iron overload, and chemotherapies. Studies have demonstrated that CB1 and TRPV1 stimulation exerts osteoclastogenic effects, whereas CB2 stimulation has an anti-osteoclastogenic role. Moreover, the EC/EV system has been demonstrated to have a role in cancer, favoring apoptosis and inhibiting cell proliferation. In particular, in bone cancer, the modulation of the EC/EV system not only reduces cell growth and enhances apoptosis but it also reduces cell invasion and bone pain in mouse models. Therefore, EC/EV receptors may be a useful pharmacological target in the prevention and treatment of bone diseases. More studies to better investigate the biochemical mechanisms underlining the EC/EV system effects in bone are needed, but the synthesis of hybrid molecules, targeting these receptors and capable of oppositely regulating bone homeostasis, seems to be a promising and encouraging prospective in bone disease management.

Cannabinoid receptor expression in estrogen-dependent and estrogen-independent endometrial cancer

The lack of good diagnostic/prognostic biomarkers and the often late presentation of endometrial cancer (EC) hinders the amelioration of the morbidity and mortality rates associated with this primarily estrogen-driven disease, a disease that is becoming more prevalent in the population. Previous studies on the expression of the classical cannabinoid receptors, CB1 and CB2, suggest these could provide good diagnostic/prognostic biomarkers for EC but those observations have been contradictory. In this study, we sought to resolve the inconsistency of CB1 and CB2 expression levels in different EC studies. To that end, we used qRT-PCR and immunohistochemistry (IHC) for CB1 and CB2 in endometrial biopsies from women with or without EC and found that transcript levels for both CB1 and CB2 were significantly decreased by 90 and 80%, respectively in EC. These observations were supported by histomorphometric studies where CB1 and CB2 staining intensity was decreased in all types of EC. These data suggest that the loss of both types of CB receptors is potentially involved in the development of or progression of EC and that CB1 and CB2 receptor expression could serve as useful histological markers and therapeutic targets in the treatment of or prevention of EC.

Insights into the effects of the endocannabinoid system in cancer: a review

In the last few decades, the endocannabinoid system has attracted a great deal of interest in terms of its applications to clinical medicine. In particular, its applications in cancer probably represent one of the therapeutic areas with most promise. On the one hand, expression of the endocannabinoid system is altered in numerous types of tumours, compared to healthy tissue, and this aberrant expression has been related to cancer prognosis and disease outcome, suggesting a role of this system in tumour growth and progression that depends on cancer type. On the other hand, cannabinoids exert an anticancer activity by inhibiting the proliferation, migration and/or invasion of cancer cells and also tumour angiogenesis. However, some cannabinoids, at lower concentrations, may increase tumour proliferation, inducing cancer growth. Enough data has been provided to consider the endocannabinoid system as a new therapeutic target in cancer, although further studies to fully establish the effect of cannabinoids on tumour progression are still needed.

Cannabinoid-induced cell death in endometrial cancer cells: involvement of TRPV1 receptors in apoptosis

Among a variety of phytocannabinoids, Δ⁹-tetrahydrocannabinol (THC) and cannabidiol (CBD) are the most promising therapeutic compounds. Besides the well-known palliative effects in cancer patients, cannabinoids have been shown to inhibit in vitro growth of tumor cells. Likewise, the major endocannabinoids (eCBs), anandamide (AEA) and 2-arachidonoylglycerol (2-AG), induce tumor cell death. The purpose of the present study was to characterize cannabinoid elements and evaluate the effect of cannabinoids in endometrial cancer cell viability. The presence of cannabinoid receptors, transient receptor potential vanilloid 1 (TRPV1), and endocannabinoid-metabolizing enzymes were determined by qRT-PCR and Western blot. We also examined the effects and the underlying mechanisms induced by eCBs and phytocannabinoids in endometrial cancer cell viability. Besides TRPV1, both EC cell lines express all the constituents of the endocannabinoid system. We observed that at concentrations higher than 5 μM, eCBs and CBD induced a significant reduction in cell viability in both Ishikawa and Hec50co cells, whereas THC did not cause any effect. In Ishikawa cells, contrary to Hec50co, treatment with AEA and CBD resulted in an increase in the levels of activated caspase -3/-7, in cleaved PARP, and in reactive oxygen species generation, confirming that the reduction in cell viability observed in the MTT assay was caused by the activation of the apoptotic pathway. Finally, these effects were dependent on TRPV1 activation and intracellular calcium levels. These data indicate that cannabinoids modulate endometrial cancer cell death. Selective targeting of TPRV1 by AEA, CBD, or other stable analogues may be an attractive research area for the treatment of estrogen-dependent endometrial carcinoma. Our data further support the evaluation of CBD and CBD-rich extracts for the potential treatment of endometrial cancer, particularly, that has become non-responsive to common therapies.

Targeting the endocannabinoid system as a potential anticancer approach

The endocannabinoid system is currently under intense investigation due to the therapeutic potential of cannabinoid-based drugs as treatment options for a broad variety of diseases including cancer. Besides the canonical endocannabinoid system that includes the cannabinoid receptors CB₁ and CB₂ and the endocannabinoids N-arachidonoylethanolamine (anandamide) and 2-arachidonoylglycerol, recent investigations suggest that other fatty acid derivatives, receptors, enzymes, and lipid transporters likewise orchestrate this system as components of the endocannabinoid system when defined as an extended signaling network. As such, fatty acids acting at cannabinoid receptors (e.g. 2-arachidonoyl glyceryl ether [noladin ether], N-arachidonoyldopamine) as well as endocannabinoid-like substances that do not elicit cannabinoid receptor activation (e.g. N-palmitoylethanolamine, N-oleoylethanolamine) have raised interest as anticancerogenic substances. Furthermore, the endocannabinoid-degrading enzymes fatty acid amide hydrolase and monoacylglycerol lipase, lipid transport proteins of the fatty acid binding protein family, additional cannabinoid-activated G protein-coupled receptors, members of the transient receptor potential family as well as peroxisome proliferator-activated receptors have been considered as targets of antitumoral cannabinoid activity. Therefore, this review focused on the antitumorigenic effects induced upon modulation of this extended endocannabinoid network.

Metabotyping human endometrioid endometrial adenocarcinoma reveals an implication of endocannabinoid metabolism

Metabolomics, an essential technique in precision medicine, contributes to the molecular fingerprinting of tumours, further helping to understand their pathogenesis. In this work, using a LC-ESI-QTOF-MS/MS platform, we demonstrated the existence of a specific metabolomic signature which could define endometrioid endometrial carcinoma (EEC), arising the endocannabinoid system as a potential pathway involved in EC pathogenesis. Metabolomics could also shed light in the processes involved in myometrial invasion, proposing new targets for possible therapeutic intervention. Consequently, we also described a different metabolomic profile in surface endometrioid carcinoma and myometrial invasive front. We validated pathways disclosed by metabolomics by immunohistochemistry. Specifically, endocannabinoid and purine metabolism could be involved in tumor myometrial invasion.

Identification of Metabolomic Biomarkers for Endometrial Cancer and Its Recurrence after Surgery in Postmenopausal Women

Endometrial cancer (EC) is the most frequent gynecological cancer in developed countries. Most EC occurs after menopause and is diagnosed as endometrioid (type I) carcinomas, which exhibit a favorable prognosis. In contrast, non-endometrioid (type II) carcinomas such as serous tumors have a poor prognosis. Our goal was to identify novel blood-based markers associated with EC subtypes and recurrence after surgery in postmenopausal women. Using mass spectrometry-based untargeted metabolomics, we examined preoperative serum metabolites among control women (n = 18) and those with non-recurrent (NR) and recurrent (R) cases of type I endometrioid (n = 24) and type II serous (n = 12) carcinomas. R and NR cases were similar with respect to pathological characteristics, body mass index, and age. A total of 1,592 compounds were analyzed including 14 different lipid classes. When we compared EC cases with controls, 137 metabolites were significantly different. A combination of spermine and isovalerate resulted in an age-adjusted area under the receiver-operating characteristic curve (AUC_adj) of 0.914 (P < 0.001) for EC detection. The combination of 2-oleoylglycerol and TAG42:2-FA12:0 allowed the distinction of R cases from NR cases with an AUC_adj of 0.901 (P < 0.001). Type I R cases were also characterized by much lower levels of bile acids and elevated concentrations of phosphorylated fibrinogen cleavage peptide, whereas type II R cases displayed higher levels of ceramides. The findings from our pilot study provide a detailed metabolomics study of EC and identify putative serum biomarkers for defining clinically relevant risk groups.

Antitumor effect of pyrrolo-1,5-benzoxazepine-15 and its synergistic effect with Oxaliplatin and 5-FU in colorectal cancer cells

Some compounds of a series of novel pyrrolo-1,5-benzoxa(thia)zepine, a well-known group of tubulin targeting agents, display anti-tumor effects mainly inducing cell cycle arrest and apoptosis in several human cancer models. A member of this family, pyrrolo-1,5-benzoxazepine-15 (PBOX-15), has previously shown potent pro-apoptotic activity in a variety of human tumor cell types, with minimal toxicity toward normal blood and bone marrow cells. In this study, we evaluated the PBOX-15-mediated effects in human colorectal cancer cell (CRC) lines, DLD-1 and HT-29. The compound, used at concentrations equal to or greater than 1 μM, inhibited the proliferation of human CRC cells, inducing a significant cell cycle arrest in the G2/M phase. In DLD-1 cells, treatments prolonged over 48 h triggered a strong activation of the intrinsic apoptotic pathway as indicated by activation of caspase-9, caspase-3 and PARP cleavage. Moreover, nanomolar concentrations of PBOX-15, significantly improved the oxaliplatin and 5-fluouracil-induced anti-proliferative effects in DLD1 cell line. The observed synergistic interaction of both PBOX-15/Oxaliplatin and PBOX-15/5FU may involve activation of p38 MAPK and JNK pathway, which in turn significantly increased caspase-3 cleavage in DLD-1 cells, treated with PBOX-5/Oxaliplatin but not with PBOX-15/5FU. Moreover, PBOX-15/5FU-treated cells showed an increase in expression of the pro-apoptotic protein Bax. Taken together, these results show that PBOX-15 could represent a promising compound for the treatment of human CRC and a strong candidate for novel therapeutic options.

Cannabinoids as Anticancer Drugs

The endocannabinoid system encompassing cannabinoid receptors, endogenous receptor ligands (endocannabinoids), as well as enzymes conferring the synthesis and degradation of endocannabinoids has emerged as a considerable target for pharmacotherapeutical approaches of numerous diseases. Besides palliative effects of cannabinoids used in cancer treatment, phytocannabinoids, synthetic agonists, as well as substances that increase endogenous endocannabinoid levels have gained interest as potential agents for systemic cancer treatment. Accordingly, cannabinoid compounds have been reported to inhibit tumor growth and spreading in numerous rodent models. The underlying mechanisms include induction of apoptosis, autophagy, and cell cycle arrest in tumor cells as well as inhibition of tumor cell invasion and angiogenic features of endothelial cells. In addition, cannabinoids have been shown to suppress epithelial-to-mesenchymal transition, to enhance tumor immune surveillance, and to support chemotherapeutics' effects on drug-resistant cancer cells. However, unwanted side effects include psychoactivity and possibly pathogenic effects on liver health. Other cannabinoids such as the nonpsychoactive cannabidiol exert a comparatively good safety profile while exhibiting considerable anticancer properties. So far experience with anticarcinogenic effects of cannabinoids is confined to in vitro studies and animal models. Although a bench-to-bedside conversion remains to be established, the current knowledge suggests cannabinoid compounds to serve as a group of drugs that may offer significant advantages for patients suffering from cancer diseases. The present review summarizes the role of the endocannabinoid system and cannabinoid compounds in tumor progression.

Endocannabinoids modulate apoptosis in endometriosis and adenomyosis

Adenomyosis that is a form of endometriosis is the growth of ectopic endometrial tissue within the muscular wall of the uterus (myometrium), which may cause dysmenorrhea and infertility. Endocannabinoid mediated apoptotic mechanisms of endometriosis and adenomyosis are not known. We hypothesized that the down regulation of endocannabinoid receptors and/or alteration in their regulatory enzymes may have a direct role in the pathogenesis of endometriosis and adenomyosis through apoptosis. Endocannabinoid receptors CB1 and CB2, their synthesizing and catabolizing enzymes (FAAH, NAPE-PLD, DAGL, MAGL) and the apoptotic indexes were immunohistochemically assessed in endometriotic and adenomyotic tissues. Findings were compared to normal endometrium and myometrium. Endometrial adenocarcinoma (Ishikawa) and ovarian endometriosis cyst wall stromal (CRL-7566) cell lines were furthermore cultured with or without cannabinoid receptor agonists. The IC50 value for CB1 and CB2 receptor agonists was quantified. Cannabinoid agonists on cell death were investigated by Annexin-V/Propidium iodide labeling with flow cytometry. CB1 and CB2 receptor levels decreased in endometriotic and adenomyotic tissues compared to the control group (p=0,001 and p=0,001). FAAH, NAPE-PLD, MAGL and DAGL enzyme levels decreased in endometriotic and adenomyotic tissues compared to control (p=0,001, p=0,001, p=0,001 and p=0,002 respectively). Apoptotic cell indexes both in endometriotic and adenomyotic tissues also decreased significantly, compared to the control group (p=0,001 and p=0,001). CB1 and CB2 receptor agonist mediated dose dependent fast anti-proliferative and pro-apoptotic effects were detected in Ishikawa and ovarian endometriosis cyst wall stromal cell lines (CRL-7566). Endocannabinoids are suggested to increase apoptosis mechanisms in endometriosis and adenomyosis. CB1 and CB2 antagonists can be considered as potential medical therapeutic agents for endometriosis and adenomyosis.

The skeletal endocannabinoid system: clinical and experimental insights

Recently, there has been a rapidly growing interest in the role of cannabinoids in the regulation of skeletal remodeling and bone mass, addressed in basic, translational and clinical research. Since the first publications in 2005, there are more than 1000 publications addressing the skeletal endocannabinoid system. This review focuses on the roles of the endocannabinoid system in skeletal biology via the cannabinoid receptors CB1, CB2 and others. Endocannabinoids play important roles in bone formation, bone resorption and skeletal growth, and are sometimes age, gender, species and strain dependent. Controversies in the literature and potential therapeutic approaches targeting the endocannabinoid system in skeletal disorders are also discussed.

Cannabinoids as Modulators of Cell Death: Clinical Applications and Future Directions

Endocannabinoids are bioactive lipids that modulate various physiological processes through G-protein-coupled receptors (CB1 and CB2) and other putative targets. By sharing the activation of the same receptors, some phytocannabinoids and a multitude of synthetic cannabinoids mimic the effects of endocannabinoids. In recent years, a growing interest has been dedicated to the study of cannabinoids properties for their analgesic, antioxidant, anti-inflammatory and neuroprotective effects. In addition to these well-recognized effects, various studies suggest that cannabinoids may affect cell survival, cell proliferation or cell death. These observations indicate that cannabinoids may play an important role in the regulation of cellular homeostasis and, thus, may contribute to tissue remodelling and cancer treatment. For a long time, the study of cannabinoid receptor signalling has been focused on the classical adenylyl cyclase/cyclic AMP/protein kinase A (PKA) pathway. However, this pathway does not totally explain the wide array of biological responses to cannabinoids. In addition, the diversity of receptors and signalling pathways that endocannabinoids modulate offers an interesting opportunity for the development of specific molecules to disturb selectively the endogenous system. Moreover, emerging evidences suggest that cannabinoids ability to limit cell proliferation and to induce tumour-selective cell death may offer a novel strategy in cancer treatment. This review describes the main properties of cannabinoids in cell death and attempts to clarify the different pathways triggered by these compounds that may help to understand the complexity of respective molecular mechanisms and explore the potential clinical benefit of cannabinoids use in cancer therapies.

Transcriptional Network Architecture of Breast Cancer Molecular Subtypes

Breast cancer heterogeneity is evident at the clinical, histological and molecular level. High throughput technologies allowed the identification of intrinsic subtypes that capture transcriptional differences among tumors. A remaining question is whether said differences are associated to a particular transcriptional program which involves different connections between the same molecules. In other words, whether particular transcriptional network architectures can be linked to specific phenotypes. In this work we infer, construct and analyze transcriptional networks from whole-genome gene expression microarrays, by using an information theory approach. We use 493 samples of primary breast cancer tissue classified in four molecular subtypes: Luminal A, Luminal B, Basal and HER2-enriched. For comparison, a network for non-tumoral mammary tissue (61 samples) is also inferred and analyzed. Transcriptional networks present particular architectures in each breast cancer subtype as well as in the non-tumor breast tissue. We find substantial differences between the non-tumor network and those networks inferred from cancer samples, in both structure and gene composition. More importantly, we find specific network architectural features associated to each breast cancer subtype. Based on breast cancer networks' centrality, we identify genes previously associated to the disease, either, generally (i.e., CNR2) or to a particular subtype (such as LCK). Similarly, we identify LUZP4, a gene barely explored in breast cancer, playing a role in transcriptional networks with subtype-specific relevance. With this approach we observe architectural differences between cancer and non-cancer at network level, as well as differences between cancer subtype networks which might be associated with breast cancer heterogeneity. The centrality measures of these networks allow us to identify genes with potential biomedical implications to breast cancer.

Overlapping molecular pathways between cannabinoid receptors type 1 and 2 and estrogens/androgens on the periphery and their involvement in the pathogenesis of common diseases (Review)

The physiological and pathophysiological roles of sex hormones have been well documented and the modulation of their effects is applicable in many current treatments. On the other hand, the physiological role of endocannabinoids is not yet clearly understood and the endocannabinoid system is considered a relatively new therapeutic target. The physiological association between sex hormones and cannabinoids has been investigated in several studies; however, its involvement in the pathophysiology of common human diseases has been studied separately. Herein, we present the first systematic review of molecular pathways that are influenced by both the cannabinoids and sex hormones, including adenylate cyclase and protein kinase A, epidermal growth factor receptor, cyclic adenosine monophosphate response element-binding protein, vascular endothelial growth factor, proto-oncogene serine/threonine-protein kinase, mitogen-activated protein kinase, phosphatidylinositol-4,5-bisphosphate 3-kinase, C-Jun N-terminal kinase and extracellular-signal-regulated kinases 1/2. Most of these influence cell proliferative activity. Better insight into this association may prove to be beneficial for the development of novel pharmacological treatment strategies for many common diseases, including breast cancer, endometrial cancer, prostate cancer, osteoporosis and atherosclerosis. The associations between cannabinoids, estrogens and androgens under these conditions are also presented and the molecular interactions are highlighted.

Discovery of novel Tetrahydrobenzo[b]thiophene and pyrrole based scaffolds as potent and selective CB2 receptor ligands: The structural elements controlling binding affinity, selectivity and functionality

CB2-based therapeutics show strong potential in the treatment of diverse diseases such as inflammation, multiple sclerosis, pain, immune-related disorders, osteoporosis and cancer, without eliciting the typical neurobehavioral side effects of CB1 ligands. For this reason, research activities are currently directed towards the development of CB2 selective ligands. Herein, the synthesis of novel heterocyclic-based CB2 selective compounds is reported. A set of 2,5-dialkyl-1-phenyl-1H-pyrrole-3-carboxamides, 5-subtituted-2-(acylamino)/(2-sulphonylamino)-thiophene-3-carboxylates and 2-(acylamino)/(2-sulphonylamino)-tetrahydrobenzo[b]thiophene-3-carboxylates were synthesized. Biological results revealed compounds with remarkably high CB2 binding affinity and CB2/CB1 subtype selectivity. Compound 19a and 19b from the pyrrole series exhibited the highest CB2 receptor affinity (Ki = 7.59 and 6.15 nM, respectively), as well as the highest CB2/CB1 subtype selectivity (∼70 and ∼200-fold, respectively). In addition, compound 6b from the tetrahydrobenzo[b]thiophene series presented the most potent and selective CB2 ligand in this series (Ki = 2.15 nM and CB2 subtype selectivity of almost 500-fold over CB1). Compound 6b showed a full agonism, while compounds 19a and 19b acted as inverse agonists when tested in an adenylate cyclase assay. The present findings thus pave the way to the design and optimization of heterocyclic-based scaffolds with lipophilic carboxamide and/or retroamide substituent that can be exploited as potential CB2 receptor activity modulators.