Search

Background and Purpose: Transient receptor potential melastatin type‐8 (TRPM8) is a cold‐sensitive cation channel protein belonging to the TRP superfamily of ion channels. Here, we reveal the molecular mechanism of TRPM8 and its clinical relevance in colorectal cancer (CRC). Experimental Approach: TRPM8 expression and its correlation with the survival rate of CRC patients was analysed. To identify the key pathways and genes related to TRPM8 high expression, Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were conducted in CRC patients. TRPM8 functional role was assessed by using Trpm8−/− mice in models of sporadic and colitis‐associated colon cancer. TRPM8 pharmacological targeting by WS12 was evaluated in murine models of CRC. Key Results: TRPM8 is overexpressed in colon primary tumours and in CD326+ tumour cell fraction. TRPM8 high expression was related to lower survival rate of CRC patients, Wnt–Frizzled signalling hyperactivation and adenomatous polyposis coli down‐regulation. In sporadic and colitis‐associated models of colon cancer, either absence or pharmacological desensitization of TRPM8 reduced tumour development via inhibition of the oncogenic Wnt/β‐catenin signalling. TRPM8 pharmacological blockade reduced tumour growth in CRC xenograft mice by reducing the transcription of Wnt signalling regulators and the activation of β‐catenin and its target oncogenes such as C‐Myc and Cyclin D1. Conclusion and Implications: Human data provide valuable insights to propose TRPM8 as a prognostic marker with a negative predictive value for CRC patient survival. Animal experiments demonstrate TRPM8 involvement in colon cancer pathophysiology and its potential as a drug target for CRC. [ABSTRACT FROM AUTHOR]

Background and Purpose: N‐Acylethanolamine acid amidase (NAAA) is a lysosomal enzyme accountable for the breakdown of N‐acylethanolamines (NAEs) and its pharmacological inhibition has beneficial effects in inflammatory conditions. The knowledge of NAAA in cancer is fragmentary with an unclarified mechanism, whereas its contribution to colorectal cancer (CRC) is unknown to date. Experimental Approach CRC xenograft and azoxymethane models were used to assess the in vivo effect of NAAA inhibition. Further, the tumour secretome was evaluated by an oncogenic array, CRC cell lines were used for in vitro studies, cell cycle was analysed by cytofluorimetry, NAAA was knocked down with siRNA, human biopsies were obtained from surgically resected CRC patients, gene expression was measured by RT‐PCR and NAEs were measured by LC–MS. Key Results: The NAAA inhibitor AM9053 reduced CRC xenograft tumour growth and counteracted tumour development in the azoxymethane model. NAAA inhibition affected the composition of the tumour secretome inhibiting the expression of EGF family members. In CRC cells, AM9053 reduced proliferation with a mechanism mediated by PPAR‐α and TRPV1. AM9053 induced cell cycle arrest in the S phase associated with cyclin A2/CDK2 down‐regulation. NAAA knock‐down mirrored the effects of NAAA inhibition with AM9053. NAAA expression was down‐regulated in human CRC tissues, with a consequential augmentation of NAE levels and dysregulation of some of their targets. Conclusion and Implications: Our results show novel data on the functional importance of NAAA in CRC progression and the mechanism involved. We propose that this enzyme is a valid drug target for the treatment of CRC growth and development. [ABSTRACT FROM AUTHOR]

Background and Purpose: Duchenne muscular dystrophy (DMD), caused by dystrophin deficiency, results in chronic inflammation and irreversible skeletal muscle degeneration. Moreover, the associated impairment of autophagy greatly contributes to the aggravation of muscle damage. We explored the possibility of using non-euphoric compounds present in Cannabis sativa, cannabidiol (CBD), cannabidivarin (CBDV) and tetrahydrocannabidivarin (THCV), to reduce inflammation, restore functional autophagy and positively enhance muscle function in vivo.Experimental Approach: Using quantitative PCR, western blots and [Ca2+ ]i measurements, we explored the effects of CBD and CBDV on the differentiation of both murine and human skeletal muscle cells as well as their potential interaction with TRP channels. Male dystrophic mdx mice were injected i.p. with CBD or CBDV at different stages of the disease. After treatment, locomotor tests and biochemical analyses were used to evaluate their effects on inflammation and autophagy.Key Results: CBD and CBDV promoted the differentiation of murine C2C12 myoblast cells into myotubes by increasing [Ca2+ ]i mostly via TRPV1 activation, an effect that undergoes rapid desensitization. In primary satellite cells and myoblasts isolated from healthy and/or DMD donors, not only CBD and CBDV but also THCV promoted myotube formation, in this case, mostly via TRPA1 activation. In mdx mice, CBD (60 mg·kg-1 ) and CBDV (60 mg·kg-1 ) prevented the loss of locomotor activity, reduced inflammation and restored autophagy.Conclusion and Implications: We provide new insights into plant cannabinoid interactions with TRP channels in skeletal muscle, highlighting a potential opportunity for novel co-adjuvant therapies to prevent muscle degeneration in DMD patients.Linked Articles: This article is part of a themed section on 8th European Workshop on Cannabinoid Research. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.10/issuetoc. [ABSTRACT FROM AUTHOR]

Background and Purpose Palmitoylethanolamide ( PEA), a naturally occurring acylethanolamide chemically related to the endocannabinoid anandamide, interacts with targets that have been identified in peripheral nerves controlling gastrointestinal motility, such as cannabinoid CB1 and CB2 receptors, TRPV1 channels and PPARα. Here, we investigated the effect of PEA in a mouse model of functional accelerated transit which persists after the resolution of colonic inflammation (post-inflammatory irritable bowel syndrome). Experimental Approach Intestinal inflammation was induced by intracolonic administration of oil of mustard ( OM). Mice were tested for motility and biochemical and molecular biology changes 4 weeks later. PEA, oleoylethanolamide and endocannabinoid levels were measured by liquid chromatography-mass spectrometry and receptor and enzyme mRNA expression by qRT- PCR. Key Results OM induced transient colitis and a functional post-inflammatory increase in upper gastrointestinal transit, associated with increased intestinal anandamide (but not 2-arachidonoylglycerol, PEA or oleoylethanolamide) levels and down-regulation of mRNA for TRPV1 channels. Exogenous PEA inhibited the OM-induced increase in transit and tended to increase anandamide levels. Palmitic acid had a weaker effect on transit. Inhibition of transit by PEA was blocked by rimonabant ( CB1 receptor antagonist), further increased by 5′-iodoresiniferatoxin (TRPV1 antagonist) and not significantly modified by the PPARα antagonist GW6471. Conclusions and Implications Intestinal endocannabinoids and TRPV1 channel were dysregulated in a functional model of accelerated transit exhibiting aspects of post-inflammatory irritable bowel syndrome. PEA counteracted the accelerated transit, the effect being mediated by CB1 receptors (possibly via increased anandamide levels) and modulated by TRPV1 channels. [ABSTRACT FROM AUTHOR]