AM251 induces apoptosis and G2/M cell cycle arrest in A375 human melanoma cells.

Human cutaneous melanoma is an aggressive and chemotherapy-resistant type of cancer. AM251 is a cannabinoid type 1 (CB1) receptor antagonist/inverse agonist with off-target antitumor activity against pancreatic and colon cancer cells. The current study aimed to characterize the in-vitro antimelanoma activity of AM251. The BRAF V600E mutant melanoma cell line, A375, was used as an in-vitro model system. Characterization tools included a cell viability assay, nuclear morphology assessment, gene expression, western blot, flow cytometry with Annexin V-FITC/7-AAD double staining, cell cycle analyses, and measurements of changes in intracellular cAMP and calcium concentrations. AM251 exerted a marked cytotoxic effect against A375 human melanoma cells with potency comparable with that observed for cisplatin without significant changes in the human dermal fibroblasts viability. AM251, at a concentration that approximates the IC50, downregulated genes encoding antiapoptotic proteins (BCL2 and survivin) and increased transcription levels of proapoptotic BAX, induced alteration of Annexin V reactivity, DNA fragmentation, chromatin condensation in the cell nuclei, and G2/M phase arrest.AM251 also induced a 40% increase in the basal cAMP levels, but it did not affect intracellular calcium concentrations. The involvement of GPR55, TRPA1, and COX-2 in the AM251 mechanism of action was excluded. The combination of AM251 with celecoxib produced a synergistic antitumor activity, although the mechanism underlying this effect remains to be elucidated. This study provides the first evidence of a proapoptotic effect and G2/M cell cycle arrest of AM251 on A375 cells. This compound may be a potential prototype for the development of promising diarylpyrazole derivatives to be evaluated in human cutaneous melanoma.

Circulating microRNAs as biomarkers for early diagnosis of cutaneous melanoma.

Introduction: Cutaneous melanoma is the deadliest form of skin cancer, with a dramatic increase in the incidence rate worldwide over the past decade. Early detection has been shown to improve the outcome of melanoma patients. The identification of noninvasive biomarkers able to identify melanoma at an early stage remains an unmet clinical need. Circulating miRNAs (c-miRNAs), small non-coding RNAs, appear as potential ideal candidate biomarkers due to their stability in biological fluids and easy detectability. Moreover, c-miRNAs are reported to be heavily deregulated in cancer patients.Areas covered: This review examines evidence of the specific c-miRNAs or panels of c-miRNAs reported to be useful in discriminating melanoma from benign cutaneous lesions.Expert opinion: Although the interesting reported by published studies, the non-homogeneity of detection and normalization methods prevents the individuation of single c-miRNA or panel of c-miRNAs that are specific for early detection of cutaneous melanoma. In the future, prospective wide and well-designed clinical trials will be needed to validate the diagnostic potential of some of the c-miRNA candidates in clinical practice.

Effect of inbreeding on the "Club Foot" disorder in Arabian Pureblood horses reared in Italy.

Background: "The Club Foot" (or "Mismatched Foot") is an acquired or congenital flexural deformity of the distal interphalangeal joint, caused by a shortening of the musculotendinous unit of the deep digital flexor tendon. Aim: The aim of this research was to detect the incidence of the disorder in Arabian Pureblood horses, attempting to understand its causes and to analyze a possible role of inbreeding in its expression. In this breed, in fact, the pathology is widespread because in the environment of origin, the rocky desert, a hard and almost goat's hoof is not disabling so the selection against this disorder has never been done. Methods: Pedigrees were taken from 141 (reference population = RP) adult Arabian Pureblood horses (51 males and 90 females) belonging to eight Italian different farms during the period 1982-2017. For each horse, the presence or not of the disorder was observed and inbreeding coefficients (F) was performed. Four grades of deformity were considered. Moreover, the environmental condition of each farm was considered: boxes, paddocks, nutrition, orientation, and hoof care and shoeing. The chi-square test was applied. Analysis of variance (ANOVA) was used to test the differences in the average inbreeding coefficient (F) between affected and healthy animals, between sexes and between shod and unshod animals. Results: Two grades of deformity were observed (I and II) which give less severe manifestations, with 28 females and 25 males (37.59% of the examined horses) showing the disorder. No differences between males and females or between shod (38.29%) and unshod (61.70%) were observed. Environmental conditions do not influence the rate of pathology in the different farms, with a prevalence of the disorder ranging from 7.69% up to 100% on farm. The whole population (WP = RP and its genealogy) included 3,355 records subdivided in seven traced generations. One hundred and eighteen out of 141 horses (RP) were inbred (83.69%). The average inbreeding coefficient (F) in the RP was 0.095. Inbreeding coefficient in RP was <0.05 in only 15 horses (12.71% of inbred), whereas it was >0.25 in 28 horses (23.73% of inbred). Conclusion: High inbreeding coefficients were observed in all farms and in particularly in affected animals suggesting that high inbreeding coefficients increases the probability that the disorder occurs. Future works may include the study of the hereditability of the character, and the attempt to identify loci associated with the disorder.

Circulating cell-free microRNAs in cutaneous melanoma staging and recurrence or survival prognosis.

Cutaneous melanoma is a skin cancer with increasing incidence. Identification of novel clinical biomarkers able to detect the stage of disease and suggest prognosis could improve treatment and outcome for melanoma patients. Cell-free microRNAs (cf-miRNAs) are the circulating copies of short non-coding RNAs involved in gene expression regulation. They are released into the interstitial fluid, are detectable in blood and other body fluids and have interesting features of ideal biomarker candidates. They are stable outside the cell, tissue specific, vary along with cancer development and are sensitive to change in the disease course such as progression or therapeutic response. Moreover, they are accessible by non-invasive methods or venipuncture. Some articles have reported different cf-miRNAs with the potential of diagnostic tools for melanoma staging, recurrence and survival prediction. Although some concordance of results is already emerging, differences in analytical methods, normalization strategies and tumour staging still will require further research and standardization prior to clinical usage of cf-miRNA analysis. This article reviews this literature with the aim of contributing to a shared focusing on these new promising tools for melanoma treatment and care.

Cholinesterase-like organocatalysis by imidazole and imidazole-bearing molecules.

Organocatalysis, which is mostly explored for its new potential industrial applications, also represents a chemical event involved in endogenous processes. In the present study, we provide the first evidence that imidazole and imidazole derivatives have cholinesterase-like properties since they can accelerate the hydrolysis of acetylthiocholine and propionylthiocholine in a concentration-dependent manner. The natural imidazole-containing molecules as L-histidine and histamine show a catalytic activity, comparable to that of imidazole itself, whereas synthetic molecules, as cimetidine and clonidine, were less active. In the experimental conditions used, the reaction progress curves were sigmoidal and the rational of such unexpected behavior as well as the mechanism of catalysis is discussed. Although indirectly, findings of the present study suggests that imidazolic compounds may interfere with the homeostasis of the cholinergic system in vivo.

Tumor-promoting effects of cannabinoid receptor type 1 in human melanoma cells.

The role of endocannabinoid system in melanoma development and progression is actually not fully understood. This study was aimed at clarifying whether cannabinoid-type 1 (CB1) receptor may function as tumor-promoting or -suppressing signal in human cutaneous melanoma. CB1 receptor expression was measured in human melanoma cell lines by real-time PCR. A genetic deletion of CB1 receptors in selected melanoma cells was carried out by using three different short hairpin RNAs (shRNAs). Performance of target gene silencing was verified by real-time PCR and Western blot. The effects of CB1 receptor silencing on cell growth, clonogenicity, migration capability, cell cycle progression, and activation of mitogenic signals was tested. Lentiviral shRNAs vectors targeting different regions of the human CB1 gene led to a significant reduction in CB1 receptor mRNA and a near complete loss of CB1 receptor protein, compared to control vector (LV-c). The number of viable cells, the colony-forming ability and cell migration were significantly reduced in cells transduced with CB1 lentiviral shRNAs compared to LV-c. Cell cycle analyses showed arrest at G1/S phase. p-Akt and p-ERK expression were decreased in transduced versus control cells. Findings of this study suggest that CB1 receptor might function as tumor-promoting signal in human cutaneous melanoma.

Immunohistochemical analysis of the distribution of desmoglein 1 and 2 in the skin of dogs and cats.

OBJECTIVE: To compare the distribution of desmoglein (Dsg) 1 and 2 in skin specimens obtained from dogs and cats to provide information about the possible role of the density of Dsg 1 and 2 in the localization of lesions attributable to pemphigus foliaceus in these 2 species. SAMPLE POPULATION: Skin biopsy specimens obtained from 4 dogs and 4 cats. PROCEDURE: Biopsy specimens were collected from the muzzle, bridge of the nose, ear, dorsum, abdomen, area adjacent to the teats, and footpads of each animal. Immunohistochemical analysis was performed on formalin-fixed, paraffin-embedded skin samples by use of a biotinylated mouse monoclonal anti-Dsg 1 and 2 antibody raised against bovine muzzle. Color development was performed by use of the streptavidin-biotin-peroxidase method with a chromogenic substrate. RESULTS: Immunohistochemical staining yielded a positive reaction in skin samples obtained from all anatomic sites. The intensity and distribution of staining were related to the number of layers of the stratum spinosum. No differences were detected between samples obtained from dogs and cats. CONCLUSIONS AND CLINICAL RELEVANCE: No differences in intensity of Dsg 1 and 2 antigen were observed in the stratum spinosum between skin samples obtained from dogs and cats. Analysis of this result suggests that factors other than the distribution of Dsg may be responsible for the differences in localization of primary clinical lesions in dogs and cats with pemphigus foliaceus.

CB1- and CB2-cannabinoid receptor-independent lipolysis induced by WIN 55,212-2 in male rat adipocytes.

The expression of genes encoding the cannabinoid CB(1) and CB(2) receptors and fatty acid amide hydrolase (FAAH) and the lipolytic activity of cannabinoid agonists were investigated in rat adipose tissue.RT-PCR studies indicated that the genes encoding CB(1) and CB(2) receptors and FAAH are not expressed in epididymal adipocytes. In functional studies, the non-selective cannabinoid receptor agonist WIN 55,212-2 concentration-dependently (0.01-30 micro M) induced glycerol release above baseline ( E(max) 96.1+/-6.2% of isoprenaline-induced lipolytic response). The selective CB(2) agonist JWH-015 (0.01-30 micro M) had no lipolytic activity while the endocannabinoid 2-arachidonoylglycerol and the stable anandamide derivative, R(+)-methanandamide had, only a weak lipolytic effect at the highest concentrations employed (10 and 30 micro M). The concentration/response relationship for WIN 55,212-2-mediated lipolytic activity, mimicked by the S(-)-enantiomer WIN 55,212-3, was shifted significantly to the right by the CB(1) antagonist AM 251 only at 10 micro M, but was not modified by the beta-adrenoceptor antagonist propranolol (1 micro M). The protein kinase inhibitor H-89, but not the two adenylyl cyclase inhibitors (+/-) N(6)- R-phenylisopropyladenosine (R-PIA, 1 micro M, a selective A(1) adenosine receptor agonist) or SQ 22,536 (50 micro M) significantly reduced the glycerol efflux induced by WIN 55,212-2. Our data suggest that the cannabinoid drug WIN 55,212-2 may exert lipolytic activity in male rat adipocytes via an intracellular mechanism, not activated by CB(1) or CB(2) receptor stimulation, significantly reversed by H-89 but not clearly linked to stimulation of adenylyl cyclase.

Selection of a human butyrylcholinesterase-like antibody single-chain variable fragment resistant to AChE inhibitors from a phage library expressed in E. coli.

Organophosphates are potent poisoning agents that cause severe cholinergic toxicity. Current treatment has been reported to be unsatisfactory and novel antidotes are needed. In this study, we used a single-chain variable fragment (scFv) library to select a recombinant antibody fragment (WZ1-14.2.1) with butyrylcholinesterase-like catalytic activity by using an innovative method integrating genetic selection and the bait-and-switch strategy. Ellman assay demonstrated that WZ1-14.2.1 has Michaelis-Menten kinetics in the hydrolysis of all the three substrates used, acetylthiocholine, propionylthiocholine and butyrylthiocholine. Notably, the catalytic activity was resistant to the following acetylcholinesterase inhibitors: neostigmine, iso-OMPA, chlorpyrifos oxon, dichlorvos, and paraoxon ethyl. Otherwise, the enzymatic activity of WZ1-14.2.1 was inhibited by the selective butyrylcholinesterase inhibitor, ethopropazine, and by the Ser-blocking agent phenylmethanesuphonyl fluoride. A hypothetical 3D structure of the WZ1-14.2.1 catalytic site, compatible with functional results, is proposed on the basis of a molecular modeling analysis.