RESUMO
WD repeat domain 5 (WDR5) is a core scaffolding component of many multiprotein complexes that perform a variety of critical chromatin-centric processes in the nucleus. WDR5 is a component of the mixed lineage leukemia MLL/SET complex and localizes MYC to chromatin at tumor-critical target genes. As a part of these complexes, WDR5 plays a role in sustaining oncogenesis in a variety of human cancers that are often associated with poor prognoses. Thus, WDR5 has been recognized as an attractive therapeutic target for treating both solid and hematological tumors. Previously, small-molecule inhibitors of the WDR5-interaction (WIN) site and WDR5 degraders have demonstrated robust in vitro cellular efficacy in cancer cell lines and established the therapeutic potential of WDR5. However, these agents have not demonstrated significant in vivo efficacy at pharmacologically relevant doses by oral administration in animal disease models. We have discovered WDR5 WIN-site inhibitors that feature bicyclic heteroaryl P7 units through structure-based design and address the limitations of our previous series of small-molecule inhibitors. Importantly, our lead compounds exhibit enhanced on-target potency, excellent oral pharmacokinetic (PK) profiles, and potent dose-dependent in vivo efficacy in a mouse MV4:11 subcutaneous xenograft model by oral dosing. Furthermore, these in vivo probes show excellent tolerability under a repeated high-dose regimen in rodents to demonstrate the safety of the WDR5 WIN-site inhibition mechanism. Collectively, our results provide strong support for WDR5 WIN-site inhibitors to be utilized as potential anticancer therapeutics.
Assuntos
Peptídeos e Proteínas de Sinalização Intracelular , Neoplasias , Repetições WD40 , Animais , Humanos , Camundongos , Cromatina , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Modelos Animais , Neoplasias/tratamento farmacológico , Linhagem Celular TumoralRESUMO
Alzheimer's disease (AD) is mainly characterized by amyloid beta (Aß) plaque deposition and neurofibrillary tangle formation due to tau hyperphosphorylation. It has been shown that astrocytes respond to these pathologies very early and exert either beneficial or deleterious effects towards neurons. Here, we identified soluble intercellular adhesion molecule-1 (ICAM-1) which is rapidly increased in astrocyte conditioned medium derived from Aß1-42 treated cultured astrocytes (Aß1-42-ACM). Aß1-42-ACM was found to be neuroprotective, however, Aß1-42-ACM deprived of ICAM-1 was unable to protect neurons against Aß1-42 mediated toxicity. Moreover, exogenous ICAM-1 renders protection to neurons from Aß1-42 induced death. It blocks Aß1-42-mediated PARP cleavage and increases the levels of anti-apoptotic proteins such as Bcl-2 and Bcl-xL, and decreases pro-apoptotic protein Bim. In an Aß-infused rat model of AD and in 5xFAD mouse, intra-peritoneal administration of ICAM-1 revealed a reduction in Aß load in hippocampal and cortical regions. Moreover, ICAM-1 treatment led to an increment in the expression of the Aß-degrading enzyme, neprilysin in 5xFAD mice. Finally, we found that ICAM-1 can ameliorate cognitive deficits in Aß-infused rat and 5xFAD mouse. Interestingly, ICAM-1 could block the NF-κB upregulation by Aß and inhibition of NF-κB recovers cognitive impairments in 5xFAD mice. Thus, our study finds a neuroprotective role of ICAM-1 and suggests that it can be a major candidate in cytokine-mediated therapy of AD.
Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Animais , Cognição , Modelos Animais de Doenças , Molécula 1 de Adesão Intercelular , Camundongos , Camundongos Transgênicos , NF-kappa B/metabolismo , Neurônios/metabolismo , RatosRESUMO
The chromatin-associated protein WD Repeat Domain 5 (WDR5) is a promising target for cancer drug discovery, with most efforts blocking an arginine-binding cavity on the protein called the 'WIN' site that tethers WDR5 to chromatin. WIN site inhibitors (WINi) are active against multiple cancer cell types in vitro, the most notable of which are those derived from MLL-rearranged (MLLr) leukemias. Peptidomimetic WINi were originally proposed to inhibit MLLr cells via dysregulation of genes connected to hematopoietic stem cell expansion. Our discovery and interrogation of small-molecule WINi, however, revealed that they act in MLLr cell lines to suppress ribosome protein gene (RPG) transcription, induce nucleolar stress, and activate p53. Because there is no precedent for an anticancer strategy that specifically targets RPG expression, we took an integrated multi-omics approach to further interrogate the mechanism of action of WINi in human MLLr cancer cells. We show that WINi induce depletion of the stock of ribosomes, accompanied by a broad yet modest translational choke and changes in alternative mRNA splicing that inactivate the p53 antagonist MDM4. We also show that WINi are synergistic with agents including venetoclax and BET-bromodomain inhibitors. Together, these studies reinforce the concept that WINi are a novel type of ribosome-directed anticancer therapy and provide a resource to support their clinical implementation in MLLr leukemias and other malignancies.
Assuntos
Peptídeos e Proteínas de Sinalização Intracelular , Proteína de Leucina Linfoide-Mieloide , Proteínas Nucleares , Ribossomos , Proteína Supressora de Tumor p53 , Humanos , Antineoplásicos/farmacologia , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Histona-Lisina N-Metiltransferase/metabolismo , Histona-Lisina N-Metiltransferase/genética , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteína de Leucina Linfoide-Mieloide/metabolismo , Proteína de Leucina Linfoide-Mieloide/genética , Proteínas Nucleares/metabolismo , Proteínas Nucleares/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Ribossomos/efeitos dos fármacos , Ribossomos/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Proteína Supressora de Tumor p53/genética , Peptidomiméticos/farmacologiaRESUMO
The chromatin-associated protein WD Repeat Domain 5 (WDR5) is a promising target for cancer drug discovery, with most efforts blocking an arginine-binding cavity on the protein called the "WIN" site that tethers WDR5 to chromatin. WIN site inhibitors (WINi) are active against multiple cancer cell types in vitro, the most notable of which are those derived from MLL-rearranged (MLLr) leukemias. Peptidomimetic WINi were originally proposed to inhibit MLLr cells via dysregulation of genes connected to hematopoietic stem cell expansion. Our discovery and interrogation of small molecule WIN site inhibitors, however, revealed that they act in MLLr cell lines to suppress ribosome protein gene (RPG) transcription, induce nucleolar stress, and activate p53. Because there is no precedent for an anti-cancer strategy that specifically targets RPG expression, we took an integrated multi-omics approach to further interrogate the mechanism of action of WINi in MLLr cancer cells. We show that WINi induce depletion of the stock of ribosomes, accompanied by a broad yet modest translational choke and changes in alternative mRNA splicing that inactivate the p53 antagonist MDM4. We also show that WINi are synergistic with agents including venetoclax and BET-bromodomain inhibitors. Together, these studies reinforce the concept that WINi are a novel type of ribosome-directed anti-cancer therapy and provide a resource to support their clinical implementation in MLLr leukemias and other malignancies.
RESUMO
Complete or partial depletion of resource in a freshwater habitat is a common phenomenon. As a consequence, aquatic fauna including bivalve molluscs may be exposed to dietary stress on a seasonal basis. Haemocyte based innate immune profile of the freshwater mollusc Lamellidens marginalis (Bivalvia: Eulamellibranchiata) was evaluated under starvation induced stress for a maximum period of 32 days in a controlled laboratory condition. During starvation, the bivalve haemocytes maintained a homeostasis in phagocytic efficacy and nitric oxide generation ability with respect to the control. The mollusc maintained a significantly high protein content in its haemolymph and tissues under the nutritional stress with respect to the control. The dietary stress had no significant impact on the activity of digestive tissue derived α-amylase till sixteenth day but by 32 days the enzyme activity went down significantly. The histopathological profile revealed that the bivalve was adapted to maintain a steady immune profile by incurring degeneration of its own tissue structure. The total haemocyte count surged significantly till 16 days but differed insignificantly with respect to the control at 32 days implying probable haematopoietic exhaustion. The study reflects the instinctive urge of the bivalve to maintain immune physiology at heavy metabolic cost under nutrient limited condition.
Assuntos
Bivalves/imunologia , Imunidade Inata , Óxido Nítrico/biossíntese , Estresse Fisiológico/imunologia , Animais , Bivalves/metabolismo , Água Doce , Hemócitos/imunologia , Fagocitose/imunologia , InaniçãoRESUMO
The aim of this investigation was to develop and optimize bisoprolol fumarate matrix tablets for sustained release application by response surface methodology based on 2(3) factorial design. The effects of the amounts of calcium alginate, HPMC K4M, and Carbopol 943 in bisoprolol fumarate matrix tablets on the properties of bisoprolol fumarate sustained release matrix tablets like drug release and hardness were analyzed and optimized. The observed responses were coincided well with the predicted values by the experimental design. The optimized bisoprolol fumarate matrix tablets showed prolonged sustained release of bisoprolol fumarate over 6 hours. These matrix tablets followed the first-order model with anomalous (non-Fickian) diffusion mechanism.