RESUMEN
Gene therapy is a revolutionary, cutting-edge approach to permanently ameliorate or amend many neuromuscular diseases by targeting their genetic origins. Motor neuron diseases and muscular dystrophies, whose genetic causes are well known, are the frontiers of this research revolution. Several genetic treatments, with diverse mechanisms of action and delivery methods, have been approved during the past decade and have demonstrated remarkable results. However, despite the high number of genetic treatments studied preclinically, those that have been advanced to clinical trials are significantly fewer. The most clinically advanced treatments include adeno-associated virus gene replacement therapy, antisense oligonucleotides, and RNA interference. This review provides a comprehensive overview of the advanced gene therapies for motor neuron diseases (i.e., amyotrophic lateral sclerosis and spinal muscular atrophy) and muscular dystrophies (i.e., Duchenne muscular dystrophy, limb-girdle muscular dystrophy, and myotonic dystrophy) tested in clinical trials. Emphasis has been placed on those methods that are a few steps away from their authoritative approval.
Asunto(s)
Enfermedad de la Neurona Motora , Atrofia Muscular Espinal , Distrofia Muscular de Duchenne , Terapia Genética/métodos , Humanos , Enfermedad de la Neurona Motora/genética , Enfermedad de la Neurona Motora/terapia , Atrofia Muscular Espinal/tratamiento farmacológico , Atrofia Muscular Espinal/terapia , Distrofia Muscular de Duchenne/tratamiento farmacológico , Distrofia Muscular de Duchenne/terapia , Oligonucleótidos Antisentido/genética , Oligonucleótidos Antisentido/uso terapéuticoRESUMEN
Increasing evidence supports the interplay between oncogenic mutations and immune escape mechanisms. Strategies to counteract the immune escape mediated by oncogenic signaling could provide improved therapeutic options for patients with various malignancies. As mutant calreticulin (CALR) is a common driver of myeloproliferative neoplasms (MPN), we analyzed the impact of oncogenic CALRdel52 on the bone marrow (BM) microenvironment in MPN. Single-cell RNA-sequencing revealed that CALRdel52 led to the expansion of TGF-ß1-producing erythroid progenitor cells and promoted the expansion of FoxP3+ regulatory T cells (Treg) in a murine MPN model. Treatment with an anti-TGF-ß antibody improved mouse survival and increased the glycolytic activity in CD4+ and CD8+ T cells in vivo, while T cell depletion abrogated the protective effects conferred by neutralizing TGF-ß. TGF-ß1 reduced perforin and TNF-α production by T cells in vitro. TGF-ß1 production by CALRdel52 cells was dependent on JAK1/2, PI3K, and ERK activity, which activated the transcription factor Sp1 to induce TGF-ß1 expression. In four independent patient cohorts, TGF-ß1 expression was increased in the BM of MPN patients compared to healthy individuals, and the BM of MPN patients contained a higher frequency of Treg compared to healthy individuals. Together, this study identified an ERK/Sp1/TGF-ß1 axis in CALRdel52 MPNs as a mechanism of immunosuppression that can be targeted to elicit T-cell-mediated cytotoxicity.
RESUMEN
The transcription factor NFE2 is overexpressed in most patients with myeloproliferative neoplasms (MPN). Moreover, mutations in NFE2, found in a subset of MPN patients, strongly predispose for transformation to acute leukemia. Transgenic mice overexpressing NFE2 as well as mice harboring NFE2 mutations display an MPN phenotype and spontaneously develop leukemia. However, the molecular mechanisms effecting NFE2-driven leukemic transformation remain incompletely understood. Here we show that the pro-leukemic histone demethylase JMJD2C constitutes a novel NFE2 target gene. JMJD2C expression is elevated in MPN patients as well as in NFE2 transgenic mice. Moreover, we show that loss of JMJD2C selectively impairs proliferation of JAK2V617F mutated cells. Our data suggest that JMJD2C represents a promising drug target in MPN and provide a rationale for further investigation in preclinical and clinical settings.
Asunto(s)
Leucemia Mieloide Aguda , Trastornos Mieloproliferativos , Animales , Ratones , Regulación de la Expresión Génica , Histona Demetilasas/genética , Janus Quinasa 2/genética , Janus Quinasa 2/metabolismo , Leucemia Mieloide Aguda/genética , Ratones Transgénicos , Mutación , Trastornos Mieloproliferativos/genética , Subunidad p45 del Factor de Transcripción NF-E2/genética , Subunidad p45 del Factor de Transcripción NF-E2/metabolismo , HumanosRESUMEN
Leukemia stem cells (LSCs) share numerous features with healthy hematopoietic stem cells (HSCs). G-protein coupled receptor family C group 5 member C (GPRC5C) is a regulator of HSC dormancy. However, GPRC5C functionality in acute myeloid leukemia (AML) is yet to be determined. Within patient AML cohorts, high GPRC5C levels correlated with poorer survival. Ectopic Gprc5c expression increased AML aggression through the activation of NF-κB, which resulted in an altered metabolic state with increased levels of intracellular branched-chain amino acids (BCAAs). This onco-metabolic profile was reversed upon loss of Gprc5c, which also abrogated the leukemia-initiating potential. Targeting the BCAA transporter SLC7A5 with JPH203 inhibited oxidative phosphorylation and elicited strong antileukemia effects, specifically in mouse and patient AML samples while sparing healthy bone marrow cells. This antileukemia effect was strengthened in the presence of venetoclax and azacitidine. Our results indicate that the GPRC5C-NF-κB-SLC7A5-BCAAs axis is a therapeutic target that can compromise leukemia stem cell function in AML.
Asunto(s)
Aminoácidos de Cadena Ramificada , Leucemia Mieloide Aguda , Receptores Acoplados a Proteínas G , Animales , Humanos , Ratones , Aminoácidos de Cadena Ramificada/uso terapéutico , Transportador de Aminoácidos Neutros Grandes 1/uso terapéutico , Leucemia Mieloide Aguda/tratamiento farmacológico , FN-kappa B/metabolismo , Receptores Acoplados a Proteínas G/metabolismoRESUMEN
DNA replication initiation requires the loading of MCM2-7 complexes at the origins of replication during G1. Replication licensing renders chromatin competent for DNA replication and its tight regulation is essential to prevent aberrant DNA replication and genomic instability. CDT1 is a critical factor of licensing and its activity is controlled by redundant mechanisms, including Geminin, a protein inhibitor of CDT1. Aberrant CDT1 and Geminin expression have been shown to promote tumorigenesis in vivo and are also evident in multiple human tumors. In this study, we developed an in vitro AlphaScreen™ high-throughput screening (HTS) assay for the identification of small-molecule inhibitors targeting the CDT1/Geminin protein complex. Biochemical characterization of the most potent compound, AF615, provided evidence of specific, dose-dependent inhibition of Geminin binding to CDT1 both in-vitro and in cells. Moreover, compound AF615 induces DNA damage, inhibits DNA synthesis and reduces viability selectively in cancer cell lines, and this effect is CDT1-dependent. Taken together, our data suggest that AF615 may serve as a useful compound to elucidate the role of CDT1/Geminin protein complex in replication licensing and origin firing as well as a scaffold for further medicinal chemistry optimisation.
RESUMEN
Even after development of the JAK1/JAK2 inhibitor ruxolitinib, myeloproliferative neoplasm (MPN) patients require novel therapeutic options. While ruxolitinib can considerably improve quality of life and prolong survival, it does not modify the natural disease course in most patients. Moreover, resistance develops with prolonged use. Therefore, various combination treatments are currently being investigated. Published data provide a compelling rationale for the inhibition of insulin growth factor-1 receptor (IGF-1R) signaling in MPN. Here we report that genetic and pharmacological inhibition of IGF-1R selectively reduced Jak2V617F-driven cytokine-independent proliferation ex vivo. Two different structurally unrelated IGF-1R inhibitors ameliorated disease phenotype in a murine MPN model and significantly prolonged survival. Moreover, in mice, low-dose ruxolitinib synergized with IGF-1R inhibition to increase survival. Our data demonstrate preclinical efficacy of IGF-1R inhibition in a murine MPN model.
RESUMEN
Neural stem cells (NSCs) are important constituents of the nervous system, and they become constrained in two specific regions during adulthood: the subventricular zone (SVZ) and the subgranular zone (SGZ) of the dentate gyrus in the hippocampus. The SVZ niche is a limited-space zone where NSCs are situated and comprised of growth factors and extracellular matrix (ECM) components that shape the microenvironment of the niche. The interaction between ECM components and NSCs regulates the equilibrium between self-renewal and differentiation. To comprehend the niche physiology and how it controls NSC behavior, it is fundamental to develop in vitro models that resemble adequately the physiologic conditions present in the neural stem cell niche. These models can be developed from a variety of biomaterials, along with different biofabrication approaches that permit the organization of neural cells into tissue-like structures. This review intends to update the most recent information regarding the SVZ niche physiology and the diverse biofabrication approaches that have been used to develop suitable microenvironments ex vivo that mimic the NSC niche physiology.