Anticancer Effect of in Vivo Inhibition of Nitric Oxide Synthase in a Rat Model of Breast Cancer

High expression of nitric oxide (NO)-synthase has been found in different cancers like cervical, breast, and central nervous system. NO-synthase activity inhibition has been suggested as a possible tool to prevent breast cancer. The anti-tumor therapeutic effect of L-nitro arginine methyl ester (L-NAME) in vivo remains understudied. Here we hypothesized that NOS inhibition by L-NAME has some antitumor effects on breast cancer development as it inhibits NO levels, which is a pathophysiological modulator of cell proliferation, cell cycle arrest, apoptosis, and angiogenesis. We utilized a novel anti-cancer treatment model by the administration of NO-synthase inhibitor L-NAME (30 mg/kg in a day, intraperitoneal), injected every third day for five weeks (in parallel to tumors evolution) in opposition to high activity of NOS during 7,12-dimethylbenz[a]anthracene-induced breast tumor in rats in vivo. The blood concentrations of nitrite anions, polyamines, malondialdehyde, NH4+ levels, and arginase activity decreased in DMBA+L-NAME-treated rats compared with DMBA rats. The reduction of these compounds also affects the decrease of the mortality rate of rats, tumor number, weight and volume, and the histopathological grade of breast cancer. Treatment with L-NAME showed increases in time of tumor incidence and body weight compared with DMBA-cancer rats. Therefore, the co-administration of L-NAME influences as a potent anti-cancer agent to treat breast cancer and can lead to the development of therapeutic methods for cancers in the future.

PARA UMA DOENÇA TÃO ANTIGA, O VISLUMBRE DE NOVOS TRATAMENTOS PROMISSORES NA DOENÇA DE CHAGAS

It has been more than 100 years since the discovery of Chagas Disease (CD). However, the repertoire indicated for its treatment is still limited. Thus, this article aims to present a review of the new pharmacological strategies being studied for CD. This literature review, consisting of 68 articles, from 1957 to 2021, was carried out on several scientific platforms. Positive effects from benznidazole have been described in the acute and chronic phases, in addition to its association with itraconazole in the acute phase. Among the cruzain inhibitors, the compound K777 presented trypanocidal effects, although demonstrating major adverse effects, while its analogue WRR-483 demonstrated great beneficial effects in vivo and in vitro. As for the nitroheterocyclics, fexinidazole showed high rates of cure in animal model, in addition to low toxicity. Nifurtimox, in early chronic stages, was able to delay the progression of tissue damage and reduce the parasite load. The compound WC-9, a squalene synthase inhibitor, showed potential inhibition of T. cruzi replication. Regarding aromatic diamidines, many compounds were able to stop the trypanosome, both in vitro and in vivo models. It was concluded that there are favorable findings to improve the treatment of CD. However, the development of effective new drugs does not only depend on their effective action, but also on numerous variables that must be circumvented, such as the reduction of side effects, treatment time and adherence to the current medication of choice, as well as the investment in production and distribution to the population.

Nitric Oxide Ameliorates Plant Metal Toxicity by Increasing Antioxidant Capacity and Reducing Pb and Cd Translocation

Recently, nitric oxide (NO) has been reported to increase plant resistance to heavy metal stress. In this regard, an in vitro tissue culture experiment was conducted to evaluate the role of the NO donor sodium nitroprusside (SNP) in the alleviation of heavy metal toxicity in a bamboo species (Arundinaria pygmaea) under lead (Pb) and cadmium (Cd) toxicity. The treatment included 200 µmol of heavy metals (Pb and Cd) alone and in combination with 200 µM SNP: NO donor, 0.1% Hb, bovine hemoglobin (NO scavenger), and 50 µM L-NAME, N(G)-nitro-L-arginine methyl ester (NO synthase inhibitor) in four replications in comparison to controls. The results demonstrated that the addition of L-NAME and Hb as an NO synthase inhibitor and NO scavenger significantly increased oxidative stress and injured the cell membrane of the bamboo species. The addition of sodium nitroprusside (SNP) for NO synthesis increased antioxidant activity, protein content, photosynthetic properties, plant biomass, and plant growth under heavy metal (Pb and Cd) toxicity. It was concluded that NO can increase plant tolerance for metal toxicity with some key mechanisms, such as increasing antioxidant activities, limiting metal translocation from roots to shoots, and diminishing metal accumulation in the roots, shoots, and stems of bamboo species under heavy metal toxicity (Pb and Cd).

Safety, Pharmacokinetics, and Pharmacodynamics of Oral Venglustat in Patients with Parkinson’s Disease and a GBA Mutation: Results from Part 1 of the Randomized, Double-Blinded, Placebo-Controlled MOVES-PD Trial

Background: Glucocerebrosidase gene (GBA) mutations influence risk and prognosis of Parkinson’s disease (PD), possibly through accumulation of glycosphingolipids, including glucosylceramide (GL-1). Venglustat is a novel, brain penetrant glucosylceramide synthase inhibitor. Objective: Evaluate venglustat pharmacology, safety, and tolerability in patients with PD and GBA mutations (GBA-PD). Methods: Part 1 of the phase 2 MOVES-PD trial (NCT02906020) was a randomized, double-blinded, placebo-controlled, dose-escalation study performed in six countries. Eligible participants included Japanese and non-Japanese patients aged 18–80 years with PD diagnosis and heterozygous GBA mutation. Participants were randomized to three doses of once-daily oral venglustat or placebo and were followed up to 36 weeks (Japanese participants: 52 weeks). Primary endpoint was venglustat safety and tolerability versus placebo. Secondary and exploratory endpoints included venglustat pharmacokinetics and pharmacodynamics. Results: Participants (N = 29) received venglustat (Japanese, n = 9; non-Japanese, n = 13) or placebo (n = 3; n = 4). Eight (89%) Japanese and 12 (92%) non-Japanese venglustat-treated participants experienced at least one adverse event (AE) versus two (67%) and four (100%) participants from the respective placebo groups. Most AEs were mild or moderate; no serious AEs or deaths occurred. Two venglustat-treated non-Japanese participants discontinued due to AEs (confusional state and panic attack). Over 4 weeks, venglustat exposure in plasma and cerebrospinal fluid (CSF) increased, and GL-1 levels in plasma and CSF decreased, both in a dose-dependent manner. At the highest dose, CSF GL-1 decreased by 72.0% in Japanese and 74.3% in non-Japanese participants. Conclusion: Venglustat showed favorable safety and tolerability in MOVES-PD Part 1 and target engagement was achieved in CSF.

The Effects of the Heat Shock Protein 90 Inhibitor 17-Allylamino-17-Demethoxygeldanamycin, Cannabinoid Agonist WIN 55,212-2, and Nitric Oxide Synthase Inhibitor Nω-Nitro-L-Arginine Methyl Ester Hydrochloride on the Serotonin and Dry Skin-Induced Itch

<b><i>Introduction:</i></b> In many types of itch, the interaction between immune system cells, keratinocytes, and sensory nerves involved in the transmission of itch is quite complex. Especially for patients with chronic itching, current treatments are insufficient, and their quality of life deteriorates significantly. <b><i>Objective:</i></b> In this study, we aimed to investigate the role of the heat shock protein 90 (Hsp90) inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG), cannabinoid agonist WIN 55,212-2, and nitric oxide (NO) synthase inhibitor Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME) in pruritus. <b><i>Methods:</i></b> We created a serotonin (5-HT)-induced (50 μg/μL/mouse, i.d.) acute and acetone-ether-water (AEW)-induced chronic itching models. 17-AAG (1, 3, and 5 mg/kg, intraperitoneally [i.p.]), WIN 55,212-2 (1 mg/kg, i.p.), and L-NAME (1 mg/kg, i.p.) were applied to Balb/c mice. <b><i>Results:</i></b> We found that 17-AAG suppressed the scratches of mice, depending on the dose. The itch behavior was reduced by WIN 55,212-2, but L-NAME showed no antipruritic effect at the administered dose. The combined application of these agents in both pruritus models showed synergism in terms of the antipruritic effect. Our results showed that NO did not play a role in the antipruritic effect of WIN 55,212-2 and 17-AAG. Increased plasma IgE levels with AEW treatment decreased with the administration of 17-AAG (5 mg/kg, i.p.) and WIN 55,212-2. <b><i>Conclusion:</i></b> These results demonstrate that Hsp90 may play a role in the peripheral pathway of pruritus, and cannabinoid agonists and Hsp90 inhibitors can be used together in the treatment of pruritus.

Metabolic drug survey highlights cancer cell dependencies and vulnerabilities

Interrogation of cellular metabolism with high-throughput screening approaches can unravel contextual biology and identify cancer-specific metabolic vulnerabilities. To systematically study the consequences of distinct metabolic perturbations, we assemble a comprehensive metabolic drug library (CeMM Library of Metabolic Drugs; CLIMET) covering 243 compounds. We, next, characterize it phenotypically in a diverse panel of myeloid leukemia cell lines and primary patient cells. Analysis of the drug response profiles reveals that 77 drugs affect cell viability, with the top effective compounds targeting nucleic acid synthesis, oxidative stress, and the PI3K/mTOR pathway. Clustering of individual drug response profiles stratifies the cell lines into five functional groups, which link to specific molecular and metabolic features. Mechanistic characterization of selective responses to the PI3K inhibitor pictilisib, the fatty acid synthase inhibitor GSK2194069, and the SLC16A1 inhibitor AZD3965, bring forth biomarkers of drug response. Phenotypic screening using CLIMET represents a valuable tool to probe cellular metabolism and identify metabolic dependencies at large.

Specifically Binding of D-Amino Neuraminic Acid to Ganglioside Studied in Prostate Cancer Cells

Aims: The aim of this study was to investigate the cellular binding site of human KDN (2-keto-3-deoxy-D-glycero-D-galacto-nononic acid). The KDN molecule is a member of the sialic acid family, and its expression increases in cancer cells. Although KDN has been shown to bind to GM3 (Monosialodihexosyl Ganglioside) in trout sperm.Methods and Results: Prostate cancer cell line (DU145) was used in this study. Each experimental group was divided into 3 groups: control, GCS (Glucosylceramide synthase) enzyme inhibitor Genz-123346 treated, and GM3 synthesis inhibitor Triptolide treated. Each group was stained using the immunocytochemical method for GM3, GD3 (Disialosyllactosylceramide) and KDN. The FTIR (Fourier Transform Infrared Spectroscopy) analysis was performed to elucidate the cellular changes upon treatment. The non-treated number 1 cell group stained positive with all of GM3, GD3 and KDN, the GCS enzyme blocked with Genz-123346 number 2 cell groups stained positive with only KDN. Furthermore, GD3 Synthase inhibitor Triptolide treated number 3 cell group stained positive with GM3 and KDN. Measurements with FTIR showed apoptotic features with Triptolide while Genz-123346 had no negative effect on the cell viability. The decrease in sugar constructions was revealed and the results that we obtained with staining were reinforced.Conclusions: Determining the location of bounded KDN is important in selecting new targets for cancer treatment researches. It has been shown that KDN is not inhibited by both GM3 inhibition and GD3 inhibition, and thus, KDN might also bind to different places, be specific, and not only attached to any of gangliosides of the GM or GD series.

Expression of the F0F1 ATP synthase inhibitor AtpΘ depends on small basic DNA-binding proteins and differential mRNA stability

F0F1 ATP synthases produce ATP, the universal biological energy source. ATP synthase complexes on cyanobacterial thylakoid membranes use proton gradients generated either by photosynthesis or respiration. AtpΘ is an ATP synthase regulator in cyanobacteria encoded by atpT. AtpΘ inhibits the hydrolysis of ATP (reverse reaction) that otherwise would occur under unfavorable conditions. In the cyanobacterium Synechocystis sp. PCC 6803, AtpΘ is expressed at very low levels under optimum phototrophic growth conditions or in the presence of glucose, but its expression is substantially increased 10 min after transfer into darkness. DNA coimmunoprecipitation experiments followed by mass spectrometry identified the binding of the two transcriptional regulators cyAbrB1 and cyAbrB2 to the promoter and the histone-like protein HU to the 5-UTR of atpT. GFP reporter assays revealed a detectable but small effect on transcriptional regulation. However, atpT transcript stabilities differed dramatically, half-lives were 1.6 min in the light, 33 min in the dark and substantial changes were observed if glucose or DCMU were added. Basic transcriptional control of atpT involves nucleoid-associated DNA-binding proteins, while the major effect on the condition-dependent regulation of atpT expression is mediated by controlling mRNA stability, which is related to the cellular redox and energy status.

Mitochondrial Membrane Potential Influences Amyloid-β Protein Precursor Localization and Amyloid-β Secretion

Background: Amyloid-β (Aβ), which derives from the amyloid-β protein precursor (AβPP), forms plaques and serves as a fluid biomarker in Alzheimer’s disease (AD). How Aβ forms from AβPP is known, but questions relating to AβPP and Aβ biology remain unanswered. AD patients show mitochondrial dysfunction, and an Aβ/AβPP mitochondria relationship exists. Objective: We considered how mitochondrial biology may impact AβPP and Aβ biology. Methods: SH-SY5Y cells were transfected AβPP constructs. After treatment with FCCP (uncoupler), Oligomycin (ATP synthase inhibitor), or starvation Aβ levels were measured. β-secretase (BACE1) expression was measured. Mitochondrial localized full-length AβPP was also measured. All parameters listed were measured in ρ0 cells on an SH-SY5Y background. iPSC derived neurons were also used to verify key results. Results: We showed that mitochondrial depolarization routes AβPP to, while hyperpolarization routes AβPP away from, the organelle. Mitochondrial AβPP and cell Aβ secretion inversely correlate, as cells with more mitochondrial AβPP secrete less Aβ, and cells with less mitochondrial AβPP secrete more Aβ. An inverse relationship between secreted/extracellular Aβ and intracellular Aβ was observed. Conclusion: Our findings indicate mitochondrial function alters AβPP localization and suggest enhanced mitochondrial activity promote Aβ secretion while depressed mitochondrial activity minimize Aβ secretion. Our data complement other studies that indicate a mitochondrial, AβPP, and Aβ nexus, and could help explain why cerebrospinal fluid Aβ is lower in those with AD. Our data further suggest Aβ secretion could serve as a biomarker of cell or tissue mitochondrial function.