RESUMO
Although recent regulatory approval of splice-switching oligonucleotides (SSOs) for the treatment of neuromuscular disease such as Duchenne muscular dystrophy has been an advance for the splice-switching field, current SSO chemistries have shown limited clinical benefit due to poor pharmacology. To overcome limitations of existing technologies, we engineered chimeric stereopure oligonucleotides with phosphorothioate (PS) and phosphoryl guanidine-containing (PN) backbones. We demonstrate that these chimeric stereopure oligonucleotides have markedly improved pharmacology and efficacy compared with PS-modified oligonucleotides, preventing premature death and improving median survival from 49 days to at least 280 days in a dystrophic mouse model with an aggressive phenotype. These data demonstrate that chemical optimization alone can profoundly impact oligonucleotide pharmacology and highlight the potential for continued innovation around the oligonucleotide backbone. More specifically, we conclude that chimeric stereopure oligonucleotides are a promising splice-switching modality with potential for the treatment of neuromuscular and other genetic diseases impacting difficult to reach tissues such as the skeletal muscle and heart.
Assuntos
Distrofia Muscular de Duchenne , Oligonucleotídeos Antissenso/química , Oligonucleotídeos Fosforotioatos/química , Animais , Éxons , Camundongos , Músculo Esquelético , Distrofia Muscular de Duchenne/tratamento farmacológico , Distrofia Muscular de Duchenne/terapia , Oligonucleotídeos Antissenso/genética , Oligonucleotídeos Antissenso/farmacologia , Oligonucleotídeos Fosforotioatos/farmacologia , Splicing de RNA/efeitos dos fármacosRESUMO
PRP4 kinase is known for its roles in regulating pre-mRNA splicing and beyond. Therefore, a wider spectrum of PRP4 kinase substrates could be expected. The role of PRP4 kinase in cancer is also yet to be fully elucidated. Attaining specific and potent PRP4 inhibitors would greatly facilitate the study of PRP4 biological function and its validation as a credible cancer target. In this report, we verified the requirement of enzymatic activity of PRP4 in regulating cancer cell growth and identified an array of potential novel substrates through orthogonal proteomics approaches. The ensuing effort in structural biology unveiled for the first time unique features of PRP4 kinase domain and its potential mode of interaction with a low molecular weight inhibitor. These results provide new and important information for further exploration of PRP4 kinase function in cancer.
Assuntos
Proteínas de Neoplasias , Neoplasias , Inibidores de Proteínas Quinases , Ribonucleoproteína Nuclear Pequena U4-U6 , Linhagem Celular Tumoral , Humanos , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/química , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/enzimologia , Neoplasias/genética , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Proteômica/métodos , Ribonucleoproteína Nuclear Pequena U4-U6/antagonistas & inibidores , Ribonucleoproteína Nuclear Pequena U4-U6/química , Ribonucleoproteína Nuclear Pequena U4-U6/genética , Ribonucleoproteína Nuclear Pequena U4-U6/metabolismoRESUMO
Huntington's disease (HD) is an autosomal dominant disease caused by the expansion of cytosine-adenine-guanine (CAG) repeats in one copy of the HTT gene (mutant HTT, mHTT). The unaffected HTT gene encodes wild-type HTT (wtHTT) protein, which supports processes important for the health and function of the central nervous system. Selective lowering of mHTT for the treatment of HD may provide a benefit over nonselective HTT-lowering approaches, as it aims to preserve the beneficial activities of wtHTT. Targeting a heterozygous single-nucleotide polymorphism (SNP) where the targeted variant is on the mHTT gene is one strategy for achieving allele-selective activity. Herein, we investigated whether stereopure phosphorothioate (PS)- and phosphoryl guanidine (PN)-containing oligonucleotides can direct allele-selective mHTT lowering by targeting rs362273 (SNP3). We demonstrate that our SNP3-targeting molecules are potent, durable, and selective for mHTT in vitro and in vivo in mouse models. Through comparisons with a surrogate for the nonselective investigational compound tominersen, we also demonstrate that allele-selective molecules display equivalent potency toward mHTT with improved durability while sparing wtHTT. Our preclinical findings support the advancement of WVE-003, an investigational allele-selective compound currently in clinical testing (NCT05032196) for the treatment of patients with HD.
RESUMO
The Akt family of kinases are activated by growth factors and regulate pleiotropic cellular activities. In this study, we provide evidence for isoform-specific positive and negative roles for Akt1 and -2 in regulating growth factor-stimulated phenotypes in breast epithelial cells. Insulin-like growth factor-I receptor (IGF-IR) hyperstimulation induced hyperproliferation and antiapoptotic activities that were reversed by Akt2 down-regulation. In contrast, Akt1 down-regulation in IGF-IR-stimulated cells promoted dramatic neomorphic effects characteristic of an epithelial-mesenchymal transition (EMT) and enhanced cell migration induced by IGF-I or EGF stimulation. The phenotypic effects of Akt1 down-regulation were accompanied by enhanced extracellular signal-related kinase (ERK) activation, which contributed to the induction of migration and EMT. Interestingly, down-regulation of Akt2 suppressed the EMT-like morphological conversion induced by Akt1 down-regulation in IGF-IR-overexpressing cells and inhibited migration in EGF-stimulated cells. These results highlight the distinct functions of Akt isoforms in regulating growth factor-stimulated EMT and cell migration, as well as the importance of Akt1 in cross-regulating the ERK signaling pathway.
Assuntos
Movimento Celular/fisiologia , Células Epiteliais/metabolismo , Mesoderma/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Biomarcadores , Mama/enzimologia , Mama/metabolismo , Linhagem Celular , Fator de Crescimento Epidérmico/metabolismo , Células Epiteliais/enzimologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Feminino , Regulação da Expressão Gênica , Humanos , Fator de Crescimento Insulin-Like I/metabolismo , Mesoderma/enzimologia , Morfogênese , Isoformas de Proteínas/metabolismo , Receptor IGF Tipo 1/metabolismo , Transdução de SinaisRESUMO
The epidermal growth factor (EGF) receptor (EGFR) family consists of four transmembrane tyrosine kinases that undergo homodimerization and heterodimerization. Pancreatic cancers overexpress these receptors. To examine the effects of EGFR blockade on pancreatic cancer cell mitogenesis in relation to activation of specific signaling pathways, four pancreatic cancer cell lines were infected with an adenoviral vector encoding a truncated EGFR (AdtrEGFR), and activation of signaling was assessed with the mitogen-activated protein kinase (MAPK) kinase inhibitors PD98059 and U0126, the p38 MAPK inhibitor SB203580, and the c-Jun NH2-terminal kinase inhibitor SP600125. In all four cell lines, AdtrEGFR markedly attenuated EGF and heparin-binding EGF-dependent cell growth, EGFR family tyrosine phosphorylation, and phosphorylation of MAPK, c-Jun NH2-terminal kinase, p38 MAPK, and activating transcription factor 2. AdtrEGFR did not alter fibroblast growth factor 2 actions on mitogenesis. In ASPC-1, PANC-1, and T3M4 cells, PD98059 and U0126 inhibited MAPK kinase activation but not EGF-stimulated mitogenesis, whereas SB203580 inhibited EGF-stimulated mitogenesis, p38 MAPK activation, and MAPK-activated protein kinase 2 activation, without attenuating the mitogenic effect of insulin-like growth factor 1. In contrast, in COLO-357 cells, PD98059, and U0126, but not SB203580, inhibited EGF-stimulated mitogenesis, whereas SP600125 did not alter the mitogenic actions of EGF in any of the cell lines. Thus, EGF promotes proliferation via the MAPK in COLO-357 cells but via p38 MAPK in ASPC-1, PANC-1, and T3M4 cells, and whereas EGFR activation leads to the activation of all four members of the EGFR family in these cells, downstream signaling is efficiently blocked by AdtrEGFR.
Assuntos
Receptores ErbB/antagonistas & inibidores , Neoplasias Pancreáticas/patologia , Adenoviridae/genética , Divisão Celular/fisiologia , Inibidores Enzimáticos/farmacologia , Fator de Crescimento Epidérmico/antagonistas & inibidores , Fator de Crescimento Epidérmico/metabolismo , Receptores ErbB/genética , Vetores Genéticos/genética , Fator de Crescimento Semelhante a EGF de Ligação à Heparina , Humanos , Peptídeos e Proteínas de Sinalização Intercelular , Sistema de Sinalização das MAP Quinases/fisiologia , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Fosforilação , Células Tumorais CultivadasRESUMO
Microarray profiling was used to investigate gene expression in the hypoxic seizure model of acquired epilepsy in the rat, with the aim of characterizing functional pathways which are persistently activated or repressed during epileptogenesis. Hippocampal and cortical tissues were transcriptionally profiled over a one week period following an initial series of seizures induced by mild hypoxia at post-natal day 10 (P10), and the gene expression data was then analyzed with a focus on gene set enrichment analysis, an approach which emphasizes regulation of entire pathways rather than of individual genes. Animals were subjected to one of three conditions: a control with no hypoxia, hypoxic seizures, and hypoxic seizures followed by treatment with the AMPAR antagonist NBQX, a compound currently proposed to be a modulator of epileptogenesis. While temporal gene expression in the control samples was found to be consistent with known processes of neuronal maturation in the rat for the given time window, the hypoxic seizure response was found to be enriched for components of the PI3K/mTOR and Wnt signaling pathways, alongside gene sets representative of glutamatergic, synaptic and axonal processes, perhaps regulated as a downstream consequence of activation of these pathways. Wnt signaling components were also found enriched in the more specifically epileptogenic NBQX-responsive gene set. While activation of the mTOR pathway is consistent with its known role in epileptogenesis and strengthens the case for mTOR or PI3K pathway inhibitors as potential anti-epileptogenic drugs, investigation of the role of Wnt signaling and the effect of appropriate inhibitors might offer a parallel avenue of research toward anti-epileptogenic treatment of epilepsy.
Assuntos
Perfilação da Expressão Gênica , Hipóxia/genética , Convulsões/genética , Serina-Treonina Quinases TOR/metabolismo , Via de Sinalização Wnt , Animais , Biomarcadores/metabolismo , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Regulação da Expressão Gênica no Desenvolvimento , Hipóxia/complicações , Hipóxia/patologia , Neurogênese/efeitos dos fármacos , Neurogênese/genética , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/patologia , Oligodendroglia/metabolismo , Oligodendroglia/patologia , Especificidade de Órgãos/efeitos dos fármacos , Especificidade de Órgãos/genética , Quinoxalinas/farmacologia , Ratos , Convulsões/complicações , Convulsões/patologia , Fatores de Tempo , Via de Sinalização Wnt/efeitos dos fármacosRESUMO
All gammaretroviruses, including murine leukemia viruses (MuLVs), feline leukemia viruses, and gibbon-ape leukemia virus, encode an alternate, glycosylated form of Gag polyprotein (glyco-Gag or gPr80gag) in addition to the polyprotein precursor of the viral capsid proteins (Pr65gag). gPr80gag is translated from an upstream in-frame CUG initiation codon, in contrast to the AUG codon used for Pr65gag. The role of glyco-Gag in MuLV replication has been unclear, since gPr80gag-negative Moloney MuLV (M-MuLV) mutants are replication competent in vitro and pathogenic in vivo. However, reversion to the wild type is frequently observed in vivo. In these experiments, in vivo inoculation of a gPr80gag mutant, Ab-X-M-MuLV, showed substantially lower (2 log) initial infectivity in newborn NIH Swiss mice than that of wild-type virus, and revertants to the wild type could be detected by PCR cloning and DNA sequencing as early as 15 days postinfection. Atomic force microscopy of Ab-X-M-MuLV-infected producer cells or of the PA317 amphotropic MuLV-based vector packaging line (also gPr80gag negative) revealed the presence of tube-like viral structures on the cell surface. In contrast, wild-type virus-infected cells showed the typical spherical, 145-nm particles observed previously. Expression of gPr80gag in PA317 cells converted the tube-like structures to typical spherical particles. PA317 cells expressing gPr80gag produced 5- to 10-fold more infectious vector or viral particles as well. Metabolic labeling studies indicated that this reflected enhanced virus particle release rather than increased viral protein synthesis. These results indicate that gPr80gag is important for M-MuLV replication in vivo and in vitro and that the protein may be involved in a late step in viral budding or release.
Assuntos
Códon sem Sentido , Produtos do Gene gag/fisiologia , Glicoproteínas/fisiologia , Vírus da Leucemia Murina/fisiologia , Proteínas Estruturais Virais/fisiologia , Replicação Viral/genética , Animais , Linhagem Celular , Fibroblastos/ultraestrutura , Fibroblastos/virologia , Produtos do Gene gag/genética , Genoma Viral/genética , Glicoproteínas/genética , Glicosilação , Vírus da Leucemia Murina/genética , Camundongos , Microscopia de Força Atômica , Modelos Animais , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Proteínas Estruturais Virais/genéticaRESUMO
Pancreatic ductal adenocarcinomas (PDACs) overexpress several members of the fibroblast growth factor (FGF) family of ligands and the type I FGF receptor (FGFR-1), and enhanced FGF-2 protein levels correlate with shorter postoperative survival of patients with PDAC. In this study, we investigated the effects of FGF-2 on cell proliferation and mitogen-activated protein kinase (MAPK) activation before and after abrogation of FGFR-1-dependent signaling in 4 pancreatic cancer cell lines (ASPC-1, COLO-357, MIA-PaCa-2, and PANC-1). Signaling was blocked by infecting the cells with an adenoviral vector encoding for a truncated FGFR-1 (AdtrFGFR-1). FGF-2 enhanced the growth of all 4 cell lines and activated MAPK in 3 of these cell lines. Infection with the AdtrFGFR-1 virus resulted in abundant expression of the truncated FGFR-1 at the RNA and protein level, markedly attenuated FGF-2-induced proliferation in all 4 tested cell lines, and decreased FGF-2-dependent MAPK activation in the 3 cell lines in which FGF-2 activated this pathway. These findings suggest that FGFR-1-mediated mitogenesis in multiple pancreatic cancer cells can be efficiently blocked with an adenoviral vector encoding a truncated FGFR-1, raising the possibility that AdtrFGFR-1 may ultimately have a therapeutic role in PDAC.