Assessment of suberoylanilide hydroxamic acid on a Alzheimer's disease model induced by ß-amyloid(1-42) in aged female mice: Neuromodulatory and epigenetic effect.

Alzheimer's disease (AD) is a neurodegenerative disease that affects several elderly people per years. AD is a pathology of multifactorial etiology, resulting from multiple environmental and genetic determinants. However, there is no effective pharmacological alternative for the treatment of this illness. In this sense, the purpose of current study was to characterize the mechanisms by which Aß1-42 injection via intracerebroventricular induces neurobehavioral changes in a time-course curve. In addition, suberoylanilide hydroxamic acid (SAHA) inhibitor of histone deacetylase (HDAC) was used to investigate the involvement of epigenetic modifications Aß1-42-caused in aged female mice. In general manner, Aß1-42 injection induced a major neurochemical disturbance in hippocampus and prefrontal cortex of animals and a serious impairment of memory. Overall, SAHA treatment attenuated neurobehavioral changes caused by Aß1-42 injection in aged female mice. The subchronic effects presented of SAHA were through modulation of HDAC activity, regulation of brain-derived neurotrophic factor (BDNF) levels and expression of BDNF mRNA, accompanied by unlocking cAMP/PKA/pCREB pathway in hippocampus and prefrontal cortex of animals.

Comment on "Preclinical assessment of histone deacetylase inhibitor quisinostat as a therapeutic agent against esophageal squamous cell carcinoma".

Recently, we read a paper "Preclinical assessment of histone deacetylase inhibitor quisinostat as a therapeutic agent against esophageal squamous cell carcinoma" published in Investigational New Drugs. Quisinostat may be a promising drug candidate for the treatment of esophageal squamous cell carcinoma. However, some problems existing in the methods part of this paper are worthy of comment.

Assessment of Synergistic Contribution of Histone Deacetylases in Prognosis and Therapeutic Management of Sarcoma.

Sarcomas are a rare group of neoplasms with a mesenchymal origin that are mainly characterized by the abnormal growth of connective tissue cells. The standard treatment for local control of sarcomas includes surgery and radiation, while for adjuvant and palliative therapy, chemotherapy has been strongly recommended. Despite the availability of multimodal therapies, the survival rate for patients with sarcoma is still not satisfactory. In recent decades, there has been a considerable effort to overcome chemotherapy resistance in sarcoma cells. This has led to the investigation of more cellular compounds implicated in gene expression and transcription processes. Furthermore, it has been discovered that histone acetylation/deacetylation equilibrium is affected in carcinogenesis, leading to a modified chromatin structure and therefore changes in gene expression. In addition, histone deacetylase inhibition is found to play a key role in limiting the tumor burden in sarcomas, as histone deacetylase inhibitors act on well-described oncogenic signaling pathways. Histone deacetylase inhibitors disrupt the increased cell motility and invasiveness of sarcoma cells, undermining their metastatic potential. Moreover, their activity on evoking cell arrest has been extensively described, with histone deacetylase inhibitors regulating the reactivation of tumor suppressor genes and induction of apoptosis. Promoting autophagy and increasing cellular reactive oxygen species are also included in the antitumor activity of histone deacetylase inhibitors. It should be noted that many studies revealed the synergy between histone deacetylase inhibitors and other drugs, leading to the enhancement of an antitumor effect in sarcomas. Therefore, there is an urgent need for therapeutic interventions modulated according to the distinct clinical and molecular characteristics of each sarcoma subtype. It is concluded that a better understanding of histone deacetylase and histone deacetylase inhibitors could provide patients with sarcoma with more targeted and efficient therapies, which may contribute to significant improvement of their survival potential.

Preclinical assessment of histone deacetylase inhibitor quisinostat as a therapeutic agent against esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) is one of the most serious life-threatening malignancies. Although chemotherapeutic targets and agents for ESCC have made much progress recently, the efficacy is still unsatisfactory. Therefore, there is still an unmet medical need for patients with ESCC. Here, we report the expression status of HDAC1 in human ESCC and matched paracancerous tissues, and the results indicated that HDAC1 was generally upregulated in ESCC specimens. Furthermore, we comprehensively assessed the anti-ESCC activity of a highly active HDAC1 inhibitor quisinostat. Quisinostat could effectively suppress cellular viability and proliferation of ESCC cells, as well as induce cell cycle arrest and apoptosis even at low treatment concentrations. The effectiveness was also observed in KYSE150 xenograft model when quisinostat was administered at tolerated doses (3 mg/kg and 10 mg/kg). Meanwhile, quisinostat also had the ability to suppress the migration and invasion (pivotal steps of tumor metastasis) of ESCC cells. Western blot analysis indicated that quisinostat exerted its anti-ESCC effects mainly through blockade of Akt/mTOR and MAPK/ERK signaling cascades. Overall, HDAC1 may serve as a potential therapeutic target for ESCC, and quisinostat deserves to be further assessed as a promising drug candidate for the treatment of ESCC.

Assessment of new HDAC inhibitors for immunotherapy of malignant pleural mesothelioma.

Background: Malignant pleural mesothelioma (MPM) is a very rare and highly aggressive cancer of the pleura associated in most cases with asbestos exposure. To date, no really efficient treatments are available for this pathology. Recently, it has been shown that epigenetic drugs, particularly DNA methylation or histone acetylation modulating agents, could be very efficient in terms of cytotoxicity for several types of cancer cells. We previously showed that a hypomethylating agent (decitabine) and a histone deacetylase inhibitor (HDACi) (valproic acid (VPA)) combination was immunogenic and led to the induction of an anti-tumor immune response in a mice model of mesothelioma. However, VPA is not very specific, is active at millimolar concentrations and is responsible for side effects in clinic. To improve this approach, we studied four newly synthetized HDACi, two hydroxamates (ODH and NODH) and two benzamides (ODB and NODB), in comparison with VPA and SAHA. We evaluated their toxicity on immune cells and their immunogenicity on MPM cells in combination with decitabine. Results: All the tested HDACi were toxic for immune cells at high concentrations. Combination with decitabine increased toxicity of HDACi only towards T-cell clone. A decrease in the proportion of regulatory T cells and natural killer cells was observed in particular with VPA and ODH. In MPM cells, all HDACi combinations induced NY-ESO-1 cancer testis antigen (CTA) expression and the recognition of the treated cells by a NY-ESO-1 specific T-CD8 clone. However, for MAGE-A1, MAGE-A3 and XAGE-1b mRNA expression, the results obtained depended on the HDACi used and on the CTA studied. Depending on the MPM cell line studied, molecules alone increased moderately PD-L1 expression. When combined, a higher stimulation of this immune check point inhibitor expression was observed. Decitabine-induced anti-viral response seemed to be inhibited in the presence of HDACi. Conclusions: This work shows that the combination of decitabine and HDACi could be of interest for MPM immunotherapy. However, this combination induced PD-L1 expression which suggests that an association with anti-PD-L1 therapy should be performed to induce an efficient anti-tumor immune response.

Advances in the Development of PET Ligands Targeting Histone Deacetylases for the Assessment of Neurodegenerative Diseases.

Epigenetic alterations of gene expression have emerged as a key factor in several neurodegenerative diseases. In particular, inhibitors targeting histone deacetylases (HDACs), which are enzymes responsible for deacetylation of histones and other proteins, show therapeutic effects in animal neurodegenerative disease models. However, the details of the interaction between changes in HDAC levels in the brain and disease progression remain unknown. In this review, we focus on recent advances in development of radioligands for HDAC imaging in the brain with positron emission tomography (PET). We summarize the results of radiosynthesis and biological evaluation of the HDAC ligands to identify their successful results and challenges. Since 2006, several small molecules that are radiolabeled with a radioisotope such as carbon-11 or fluorine-18 have been developed and evaluated using various assays including in vitro HDAC binding assays and PET imaging in rodents and non-human primates. Although most compounds do not readily cross the blood-brain barrier, adamantane-conjugated radioligands tend to show good brain uptake. Until now, only one HDAC radioligand has been tested clinically in a brain PET study. Further PET imaging studies to clarify age-related and disease-related changes in HDACs in disease models and humans will increase our understanding of the roles of HDACs in neurodegenerative diseases.

Assessment of Topical Therapies for Improving the Optical Clarity Following Stromal Wounding in a Novel Ex Vivo Canine Cornea Model.

Purpose: To evaluate the effect of topical suberanilohydroxamic acid (SAHA) and 5-methyl-1-phenyl-2[1H]-pyridone (pirfenidone) on the degree of corneal haze in the stromal wounded ex vivo canine cornea. Methods: Twenty-four corneoscleral rims from normal dogs were uniformly wounded with an excimer laser and placed into culture medium with an air-liquid interface. The control group (n = 8) contained placebo-treated corneas. Treatment group 1 (n = 8) received SAHA topically every 6 hours. Treatment group 2 (n = 8) received pirfenidone topically every 6 hours. Each cornea was fluorescein stained and macrophotographed every 6 hours to assess epithelialization rate. All corneas were also macrophotographed weekly to assess optical clarity (haze). Images were analyzed for differences in pixel intensity between wounded (haze) and unwounded (nonhaze) regions, and haze surface area for each cornea was calculated. Results: The mean epithelialization time was 47.25 hours in the control group, 45.00 hours in the SAHA group, and 43.50 hours in the pirfenidone group, revealing no significant difference (P = 0.368). The median difference in pixel intensity between haze and nonhaze areas was 21.5 in the control group, 8.0 in the SAHA group, and 8.0 in the pirfenidone group, which is significant (P < 0.01). The median haze surface area was 12.96 mm2 in the control group, 5.70 mm2 in the SAHA group, and 5.92 mm2 in the pirfenidone group, which is significant (P < 0.01). Conclusions: Stromal-wounded ex vivo canine corneas exhibited greater optical clarity when treated with SAHA and pirfenidone than when placebo treated at 21 days. There was no significant difference in epithelialization rate between groups. Corneal contour was correlated with geographic haze distribution.

Treatment-free interval as a metric of patient experience and a health outcome of value for advanced multiple myeloma: the case for the histone deacetylase inhibitor panobinostat, a next-generation novel agent.

BACKGROUND: Patients with relapsed or relapsed/refractory multiple myeloma (RRMM) face poor treatment options by the time third-line therapy is required, despite advances in overall survival in recent years. Treatment free interval (TFI) and opportunities to maintain quality of life (QoL) have been cited as additional measures of efficacy that can be utilized in personalized treatment decisions. METHODS: The clinical health outcomes data from PANORAMA-1, the pivotal phase-3 trial comparing panobinostat-bortezomib-dexamethasone (PAN-BTZ-DEX) with placebo (PBO)-BTZ-DEX in RRMM patients treated with 1 to 3 prior regimens, retrospectively assessed TFI as a health outcome measure and metric of patient treatment experience relevant to the RRMM population. RESULTS: PAN-BTZ-DEX shows promise for prolonged TFI (mean TFI, 7.49 months; 95% CI, 6.02 to 8.71) compared to PBO-BTZ-DEX (mean TFI, 3.86 months; 95% CI, 3.08 to 4.60) for heavily pre-treated advanced RRMM patients), due to the short duration of therapy and extended progression free-survival. Further, QoL during the TFI was similar to baseline. CONCLUSIONS: PAN-BTZ-DEX provides a treatment regimen with prolonged TFI benefits previously not available for RRMM patients. TFI has not been traditionally measured in clinical trials, but should be assessed in prospective data collection given its value to payers, providers, and patients.

Sirtuin modulators: an updated patent review (2012 - 2014).

INTRODUCTION: Since 2000 sirtuins (SIRT1-7) have gained growing attention for their connections with many biological processes such as cellular metabolism regulation, neuroprotection, apoptosis, inflammation, and cancer progression. In particular, SIRT1 has been the most studied isoform, not only for its role during caloric restriction but also as target in prevention of aging-related diseases. SIRT inhibition can be useful for treating cancer, HIV infection or muscular diseases, SIRT activation can exert positive effects in aging-related disorders such as metabolism, cardiovascular, and neurodegenerative diseases. AREAS COVERED: This review includes the patents about sirtuin modulation released during the 2012 - 2014 period, and covers the potential therapeutic uses of known sirtuin modulators as well as new related small molecules in various disease contexts. EXPERT OPINION: The effective role of sirtuins in cancer is still controversial, because some of them seem to have tumor-promoter as well as tumor-suppressor properties. Thus, few patents describing SIRT inhibitors have been found in 2012 - 2014 period. Despite the still active debate on their role as direct or indirect activators of SIRT1, sirtuin-activating compounds are actually subjected to intense research for the ability to treat neurodegenerative diseases, metabolic disorders, inflammation, vascular system injuries, wound healing and endothelial dysfunctions. A great number of clinical trials are reported with either SIRT inhibitors or activators, thus it is possible that in the foreseeable future one or more of them will enter in the clinical arena.

Foundation-directed therapeutic development in Huntington's disease.

Huntington's disease (HD) is an autosomal dominant neurodegenerative disease that devastates patients and their families. It is caused by expansion of the CAG repeat in the huntingtin gene (HTT) and characterized pathologically by the loss of pyramidal neurons in several cortical areas, striatal medium spiny neurons, and hypothalamic neurons. Clinically, a distinguishing feature of the disease is uncontrolled involuntary movements (chorea) accompanied by progressive cognitive and psychiatric impairment. Currently there are no effective disease-modifying treatments for HD, although antidepressant and antipsychotic medications are typically utilized to manage HD symptoms, in addition to the only approved drug for the treatment of chorea in HD, tetrabenazine (TBZ). CHDI is a not-for-profit organization focused solely on HD. Herein we describe our foundation-directed therapeutic development efforts highlighting our collaborations and internal programs that are in various stages of development.