This manuscript describes a novel class of N-acylhydrazone (NAH) derivatives that act as histone deacetylase (HDAC) 6/8 dual inhibitors and were designed from the structure of trichostatin A (1). Para-substituted phenyl-hydroxamic acids presented a more potent inhibition of HDAC6/8 than their meta analogs. In addition, the effect of compounds (E)-4-((2-(4-(dimethylamino)benzoyl)hydrazono)methyl)-N-hydroxybenzamide (3c) and (E)-4-((2-(4-(dimethylamino)benzoyl)-2-methylhydrazono)methyl)-N-hydroxybenzamide (3f) on the acetylation of α-tubulin revealed an increased level of acetylation. These two compounds also affected cell migration, indicating their inhibition of HDAC6. An analysis of the antiproliferative activity of these compounds, which presented the most potent activity, showed that compound 3c induced cell cycle arrest and 3g induced apoptosis through caspase 3/7 activation. These results suggest HDAC6/8 as a potential target of future molecular therapies for cancer.

Geopropolis is produced by some stingless bee species, such as Melipona fasciculata Smith, a native species from Brazil. This study aims to investigate the antioxidant and anti-inflammatory activities and cytotoxicity effects of geopropolis hydroethanolic extracts against lung (H460 and A549) and ovarian (A2780 and ES2) cancer cell lines and non-tumor (HUVEC) cell lines using chemical identification by LC/MS/MS analysis and in silico assays to determine which compounds are associated with bioactivity. The antioxidant activity of extracts and inhibitory activity against COX enzymes were assessed by in vitro assays; cytotoxicity effect was evaluated by the MTT assay; cell cycle was assessed by flow cytometry and apoptosis by Western blotting. The geopropolis extracts showed great radical scavenging potential, preferential inhibition of COX-2, decreased cancer cell viability, non-cytotoxic effects against the non-tumoral cell line, besides modulating the cell cycle and inducing cancer cell apoptosis through the activation of caspase-3 and PARP protein cleavage. The in silico study suggests that corilagin, typhaneoside, taraxerone and marsformosanone, identified by LC/MS/MS, can be associated with anti-inflammatory activity and cytotoxic effects. Thus, the current study suggests the potential of geopropolis concerning the research field of new pharmacological alternatives regarding cancer therapy.

The study provides strong evidence for the synergistic effects of the association with HDCI and chemotherapy in BL cells.

Leishmaniasis is a spectrum of infectious diseases caused by Leishmania protozoan parasites. The purpose of this study was to perform, in vitro, a comparative analysis of the activity amastigotes. Results showed excellent efficacy of all compounds against axenic amastigotes, compared to pentamidine isethionate, the reference drug used. The cytotoxic effect of these mesoionic compounds of six mesoionic compounds (three 1,3,4-thiadiazolium-2-aminide and three 1,2,3-oxadiazolium-5-olate class compounds) was evaluated in mouse peritoneal macrophages using MTT assay, low toxicity (≈ 10%) for these mammalian cells being observed. In an attempt to define a potential drug target, the activities of nitric oxide synthase (NOS) and arginase of the parasites treated with the mesoionic derivatives were evaluated. NOS was purified from a cell-free extract of infective promastigotes and axenic amastigotes and all derivatives tested were able to inhibit the enzyme as monitored by the decrease of NADPH consumption. Arginase activity from both stages of the parasite was measured using urea production and none of the compounds inhibited the enzyme activity of axenic amastigotes. However, the compounds without substituents (MI-H and SID-H) were able to inhibit arginase activity of these parasites.

Particulate formulations can significantly increase both potency and safety profiles of opioids.

Transcriptome studies have reported the dysregulation of cell cycle-related genes and the global inhibition of host mRNA translation in COVID-19 cases. However, the key genes and cellular mechanisms that are most affected by the severe outcome of this disease remain unclear. For this work, the RNA-seq approach was used to study the differential expression in buffy coat cells of two groups of people infected with SARS-CoV-2: (a) Mild, with mild symptoms; and (b) SARS (Severe Acute Respiratory Syndrome), who were admitted to the intensive care unit with the severe COVID-19 outcome. Transcriptomic analysis revealed 1009 up-regulated and 501 down-regulated genes in the SARS group, with 10% of both being composed of long non-coding RNA. Ribosome and cell cycle pathways were enriched among down-regulated genes. The most connected proteins among the differentially expressed genes involved transport dysregulation, proteasome degradation, interferon response, cytokinesis failure, and host translation inhibition. Furthermore, interactome analysis showed Fibrillarin to be one of the key genes affected by SARS-CoV-2. This protein interacts directly with the N protein and long non-coding RNAs affecting transcription, translation, and ribosomal processes. This work reveals a group of dysregulated processes, including translation and cell cycle, as key pathways altered in severe COVID-19 outcomes.

Histone deacetylase 6 (HDAC6) catalyses the removal of acetyl groups from the lysine residues of a series of non-histone proteins, e.g., α-tubulin, Hsp90 and cortactin. The design of selective inhibitors of HDAC6 is related with important outcomes in the oncological, immunological and neurological fields. Herein, we describe the design, synthesis and pharmacological evaluation of a series of N-acylhydrazones (NAH) designed from the trichostatin A as HDAC6 inhibitors. The use of the phenyl linker in the design of the compounds led to HDAC6 selectivity among the HDAC family. Para-substituted phenylhydroxamic acids presented a more potent inhibition of HDAC6 than their meta-substituted analogs. The N-and C-methylation of the NAH framework attached to para-substituted phenyl-hydroxamic unit was evaluated and the compound LASSBio-1911 was identified as a potent and selective HDAC6 inhibitor (IC 50 = 15 nM). In the next step, we evaluated the influence of the cap group. We found that the use of different aromatic and heteroaromatic rings did not influence the inhibition of HDAC6. Some of these compounds were able to reduce significantly cell migration, corroborating their inhibitory profile against HDAC6. On the other hand, an analysis of their antiproliferative activity against different tumor cell lines showed that they can induce cell cycle arrest or induce apoptosis through caspase 3/7 activation, with particular relevance for hepatocellular carcinoma (HepG2) cells.

Introduction: Histone Deacetylase Inhibitors (HDACis) have been actively explored as a new generation of anticancer drugs, generally known as epigenetic therapeutics and emerging as promising agents for the treatment of T-cell lymphomas. Panobinostat (Novartis Pharmaceuticals, Basel, Switzerland) is a novel cinnamic hydroxamic acid analogue HDACi that inhibits proliferation and induces apoptosis in tumor cell lines. Recent findings indicate that HDACi repress angiogenesis, a process essential for tumor metabolism and progression, through hypoxiainducible factors (HIF) which are the master regulator of cellular adaptation to hypoxia. In addition, HDACis apoptotic-effect was detected to occur through reactivation of Bim expression, a proapoptotic BH3-only family protein, which has attracted increasing attention as a target for tumor therapy. However, its effects on Burkitt's lymphoma (BL) cells are not entirely elucidated. Here we evaluate the efficacy of combined treatment of HDACi, Panobinostat, with Cisplatin (CDDP) or Etoposide (VP-16) in well characterized BL cell lines in order to analyze the molecular basis affected by the single and combined agents. Methods: Burkitt's Lymphoma cell lines Raji and Daudi were maintained in RPMI culture medium and incubated with Panobinostat 0.1nM combined with CDDP 1.0 and 2.5μM or VP-16 0.1 and 0.3 μM during 24h for Raji and 48h for Daudi cells. Apoptosis and mitochondrial membrane potential (MMP) were accessed by flow cytometry using Annexin-V/PI and DiOC6 respectively. Drug interaction was calculated by Fischel et al., 2005 method for determining combination index (R). Pro-Caspase-3, Pro-Caspase-9 and PARP cleavage was analyzed by western blotting using β-actin as loading control. Real-Time RT PCR was used to evaluate Bim and HIF-1α gene expressions. Results: Apoptosis was enhanced by the combined treatments (Panobinostat/CDDP and Panobinostat/VP-16), when compared with single treatment. The combination of Panobinostat and VP-16 induced apoptosis in 59,9% of Raji cells compared to 20,4% for Panobinostat alone and 33.3% for VP-16 0.3 μM alone resulting in synergistic R value of 0.77. Moreover, in Daudi cell line we observed an additive effects (R=1.1) of both combinations. The apoptosis effects were followed by MMP decreased levels in a dose-dependent manner and by cleavage of pro-caspase-3, pro-caspase-9 and PARP in both BL cell lines. Additionally, apoptotic profile was correlated with Bim and HIF-1α mRNA upregulation. Conclusions: These pre-clinical data suggests the potential therapeutic role of Panobinostat for the treatment of BL. In order to identify and validate possible targets and/or biomarkers for these combined treatments further studies are in progress. Financial support: Novartis FAF2301422, Associação Vencer FAF2301402, INCT para Controle do Câncer, CNPq 573806/2008-0, FAPERJ E26/170.026/2008 and Ministério da Saúde (M.S.). Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B44.