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Deregulation of transcription factors (TFs) leading to uncontrolled proliferation of tumor cells within the microenvironment represents a hallmark of cancer. However, the biological and clinical impact of transcriptional interference, particularly in multiple myeloma (MM) cells, remains poorly understood. The present study shows for the first time that MYC and JUNB, two crucial TFs implicated in MM pathogenesis, orchestrate distinct transcriptional programs. Specifically, our data revealed that expression levels of MYC, JUNB, and their respective downstream targets do not correlate and that their global chromatin-binding patterns are not significantly overlapping. Mechanistically, MYC expression was not affected by JUNB knockdown, and conversely, JUNB expression and transcriptional activity were not affected by MYC knockdown. Moreover, suppression of MYC levels in MM cells via targeting the master regulator BRD4 by either siRNA-mediated knockdown or treatment with the novel proteolysis targeting chimera (PROTAC) MZ-1 overcame bone marrow (BM) stroma cell/IL-6-induced MYC- but not MEK-dependent JUNB-upregulation and transcriptional activity. Consequently, targeting of the two non-overlapping MYC- and JUNB-transcriptoms by MZ-1 in combination with genetic or pharmacological JUNB-targeting approaches synergistically enhanced MM cell death, both in 2D and our novel dynamic 3D models of the BM milieu as well as in murine xenografts. In summary, our data emphasize the opportunity to employ MYC and JUNB dual-targeting treatment strategies in MM as another exciting approach to further improve patient outcomes.
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Regulación Neoplásica de la Expresión Génica , Mieloma Múltiple , Proteínas Proto-Oncogénicas c-myc , Factores de Transcripción , Mieloma Múltiple/genética , Mieloma Múltiple/tratamiento farmacológico , Mieloma Múltiple/patología , Mieloma Múltiple/metabolismo , Humanos , Animales , Ratones , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Línea Celular Tumoral , Ensayos Antitumor por Modelo de Xenoinjerto , Proteínas Proto-Oncogénicas c-jun/metabolismo , Proteínas Proto-Oncogénicas c-jun/genéticaRESUMEN
ABSTRACT: Hematopoietic stem cells (HSCs) are characterized by the ability to self-renew and to replenish the hematopoietic system. The cell-cycle kinase cyclin-dependent kinase 6 (CDK6) regulates transcription, whereby it has both kinase-dependent and kinase-independent functions. Herein, we describe the complex role of CDK6, balancing quiescence, proliferation, self-renewal, and differentiation in activated HSCs. Mouse HSCs expressing kinase-inactivated CDK6 show enhanced long-term repopulation and homing, whereas HSCs lacking CDK6 have impaired functionality. The transcriptomes of basal and serially transplanted HSCs expressing kinase-inactivated CDK6 exhibit an expression pattern dominated by HSC quiescence and self-renewal, supporting a concept, in which myc-associated zinc finger protein (MAZ) and nuclear transcription factor Y subunit alpha (NFY-A) are critical CDK6 interactors. Pharmacologic kinase inhibition with a clinically used CDK4/6 inhibitor in murine and human HSCs validated our findings and resulted in increased repopulation capability and enhanced stemness. Our findings highlight a kinase-independent role of CDK6 in long-term HSC functionality. CDK6 kinase inhibition represents a possible strategy to improve HSC fitness.
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Quinasa 6 Dependiente de la Ciclina , Células Madre Hematopoyéticas , Quinasa 6 Dependiente de la Ciclina/metabolismo , Quinasa 6 Dependiente de la Ciclina/genética , Animales , Células Madre Hematopoyéticas/metabolismo , Células Madre Hematopoyéticas/citología , Ratones , Humanos , Células Madre Adultas/metabolismo , Células Madre Adultas/citología , Proliferación Celular , Diferenciación Celular , Ratones Endogámicos C57BL , Trasplante de Células Madre Hematopoyéticas , Autorrenovación de las Células/efectos de los fármacosRESUMEN
Multiple neurological disorders are associated with gastrointestinal (GI) symptoms, including autism spectrum disorder (ASD). However, it is unclear whether GI distress itself can modify aspects of behavior. Here, we show that mice that experience repeated colitis have impaired active social engagement, as measured by interactions with a foreign mouse, even though signs of colitis were no longer present. We then tested the hypothesis that individuals with ASD harbor a microbiota that might differentially influence GI health by performing microbiota transplantation studies into male germfree animals, followed by induction of colitis. Animals that harbor a microbiota from ASD individuals have worsened gut phenotypes when compared to animals colonized with microbiotas from familial neurotypical (NT) controls. We identify the enrichment of Blautia species in all familial NT controls and observe an association between elevated abundance of Bacteroides uniformis and reductions in intestinal injury. Oral treatment with either of these microbes reduces colon injury in mice. Finally, provision of a Blautia isolate from a NT control ameliorates gut injury-associated active social engagement in mice. Collectively, our data demonstrate that past intestinal distress is associated with changes in active social behavior in mice that can be ameliorated by supplementation of members of the human microbiota.
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Trastorno del Espectro Autista , Colitis , Enfermedades Gastrointestinales , Microbiota , Humanos , Masculino , Ratones , Animales , Trastorno del Espectro Autista/terapia , Participación Social , Colitis/terapia , Suplementos DietéticosRESUMEN
RATIONALE: Cardiovascular disease (CVD) is a leading cause of morbidity and mortality among individuals with chronic obstructive pulmonary disease (COPD). Black women with COPD are at elevated risk of CVD-related mortality compared to White women. CVD risk factors are undertreated in Black men and women. However, barriers to CVD prevention from the perspective of Black individuals living with COPD have not been previously identified. OBJECTIVE: To identify barriers and facilitators for CVD prevention among Black individuals living with COPD. METHODS: We conducted semi-structured interviews with Black participants living with COPD and attending clinics at two urban hospitals. Participants were included if they had physician confirmed COPD diagnosis and presence of CVD or CVD risk factors. Participants were interviewed until thematic saturation was reached, with additional interviews conducted to confirm saturation. Data were analyzed using thematic analysis, iteratively revising, and updating the codebook by consensus of the study team. Codes were grouped into categories, subthemes, and themes. Themes were organized using the social ecological framework into individual, interpersonal, health system, and societal levels. RESULTS: We interviewed 30 participants of mean age 67.8 ± 8.3 years; 17 (57%) were Black women and 13 (43%) were Black men. Individual-level themes were: living with COPD and resultant multimorbidity impacts CVD prevention (theme 1), and self-efficacy and advocacy impact care received (theme 2). At the interpersonal level: supportive relationships facilitate improved access to CVD prevention (theme 3). System level themes were: health systems are not designed to support patients with COPD and CVD (theme 4), and health systems do not deliver effective patient education (theme 5). At the societal level: structural barriers and racism prevent accessing care and adopting a healthy lifestyle (theme 6). CONCLUSIONS: We identified barriers to CVD prevention at all levels of the socio-ecological framework for Black individuals living with COPD. To maximize their impact, future interventions to prevent CVD among individuals with COPD can use these findings to target barriers at multiple levels.
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Low-protein diets promote metabolic health in humans and rodents. Despite evidence that sex and genetic background are key factors in the response to diet, most protein intake studies examine only a single strain and sex of mice. Using multiple strains and both sexes of mice, we find that improvements in metabolic health in response to reduced dietary protein strongly depend on sex and strain. While some phenotypes were conserved across strains and sexes, including increased glucose tolerance and energy expenditure, we observed high variability in adiposity, insulin sensitivity, and circulating hormones. Using a multi-omics approach, we identified mega-clusters of differentially expressed hepatic genes, metabolites, and lipids associated with each phenotype, providing molecular insight into the differential response to protein restriction. Our results highlight the importance of sex and genetic background in the response to dietary protein level, and the potential importance of a personalized medicine approach to dietary interventions.
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Dieta con Restricción de Proteínas , Resistencia a la Insulina , Animales , Metabolismo Energético/genética , Femenino , Factores de Crecimiento de Fibroblastos/metabolismo , Antecedentes Genéticos , Resistencia a la Insulina/genética , Hígado/metabolismo , Masculino , RatonesRESUMEN
Listeria monocytogenes (L. monocytogenes) is a food-borne bacterial pathogen. Innate immunity to L. monocytogenes is profoundly affected by type I interferons (IFN-I). Here we investigated host metabolism in L. monocytogenes-infected mice and its potential control by IFN-I. Accordingly, we used animals lacking either the IFN-I receptor (IFNAR) or IRF9, a subunit of ISGF3, the master regulator of IFN-I-induced genes. Transcriptomes and metabolite profiles showed that L. monocytogenes infection induces metabolic rewiring of the liver. This affects various metabolic pathways including fatty acid (FA) metabolism and oxidative phosphorylation and is partially dependent on IFN-I signaling. Livers and macrophages from Ifnar1-/- mice employ increased glutaminolysis in an IRF9-independent manner, possibly to readjust TCA metabolite levels due to reduced FA oxidation. Moreover, FA oxidation inhibition provides protection from L. monocytogenes infection, explaining part of the protection of Irf9-/- and Ifnar1-/- mice. Our findings define a role of IFN-I in metabolic regulation during L. monocytogenes infection. Metabolic differences between Irf9-/- and Ifnar1-/- mice may underlie the different susceptibility of these mice against lethal infection with L. monocytogenes.
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Interferón Tipo I/metabolismo , Listeria monocytogenes/metabolismo , Listeriosis/metabolismo , Hígado/metabolismo , Animales , Ácidos Grasos/metabolismo , Interferón Tipo I/inmunología , Listeria monocytogenes/inmunología , Listeriosis/inmunología , Hígado/inmunología , Ratones , Ratones Endogámicos C57BLRESUMEN
The transcription factors signal transducer and activator of transcription 5A (STAT5A) and STAT5B are critical in hematopoiesis and leukemia. They are widely believed to have redundant functions, but we describe a unique role for STAT5B in driving the self-renewal of hematopoietic and leukemic stem cells (HSCs/LSCs). We find STAT5B to be specifically activated in HSCs and LSCs, where it induces many genes associated with quiescence and self-renewal, including the surface marker CD9. Levels of CD9 represent a prognostic marker for patients with STAT5-driven leukemia, and our findings suggest that anti-CD9 antibodies may be useful in their treatment to target and eliminate LSCs. We show that it is vital to consider STAT5A and STAT5B as distinct entities in normal and malignant hematopoiesis.
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Células Madre Hematopoyéticas/patología , Leucemia/patología , Células Madre Neoplásicas/patología , Factor de Transcripción STAT5/metabolismo , Transducción de Señal , Tetraspanina 29/metabolismo , Animales , Autorrenovación de las Células , Hematopoyesis , Células Madre Hematopoyéticas/citología , Células Madre Hematopoyéticas/metabolismo , Humanos , Leucemia/metabolismo , Ratones , Ratones Endogámicos C57BL , Células Madre Neoplásicas/citología , Células Madre Neoplásicas/metabolismo , Células Tumorales CultivadasRESUMEN
Low-protein diets promote metabolic health in rodents and humans, and the benefits of low-protein diets are recapitulated by specifically reducing dietary levels of the three branched-chain amino acids (BCAAs), leucine, isoleucine, and valine. Here, we demonstrate that each BCAA has distinct metabolic effects. A low isoleucine diet reprograms liver and adipose metabolism, increasing hepatic insulin sensitivity and ketogenesis and increasing energy expenditure, activating the FGF21-UCP1 axis. Reducing valine induces similar but more modest metabolic effects, whereas these effects are absent with low leucine. Reducing isoleucine or valine rapidly restores metabolic health to diet-induced obese mice. Finally, we demonstrate that variation in dietary isoleucine levels helps explain body mass index differences in humans. Our results reveal isoleucine as a key regulator of metabolic health and the adverse metabolic response to dietary BCAAs and suggest reducing dietary isoleucine as a new approach to treating and preventing obesity and diabetes.
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Aminoácidos de Cadena Ramificada/metabolismo , Dieta , Isoleucina/metabolismo , Valina/metabolismo , Tejido Adiposo Blanco/metabolismo , Animales , Índice de Masa Corporal , Dieta/veterinaria , Metabolismo Energético , Factores de Crecimiento de Fibroblastos/deficiencia , Factores de Crecimiento de Fibroblastos/genética , Factores de Crecimiento de Fibroblastos/metabolismo , Humanos , Hígado/metabolismo , Masculino , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Obesidad/metabolismo , Obesidad/patología , Proteínas Serina-Treonina Quinasas/metabolismo , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismoRESUMEN
Tumor metastasis is the leading cause of death worldwide and involves an extremely complex process composed of multiple steps. Our previous study demonstrated that apoptosis signal-regulating kinase 1 (ASK1) deficiency in mice attenuates tumor metastasis in an experimental lung metastasis model. However, the steps of tumor metastasis regulated by ASK1 remain unclear. Here, we showed that ASK1 deficiency in mice promotes natural killer (NK) cell-mediated intravascular tumor cell clearance in the initial hours of metastasis. In response to tumor inoculation, ASK1 deficiency upregulated immune response-related genes, including interferon-gamma (IFNγ). We also revealed that NK cells are required for these anti-metastatic phenotypes. ASK1 deficiency augmented cytokine production chemoattractive to NK cells possibly through induction of the ligand for NKG2D, a key activating receptor of NK cells, leading to further recruitment of NK cells into the lung. These results indicate that ASK1 negatively regulates NK cell-dependent anti-tumor immunity and that ASK1-targeted therapy can provide a new tool for cancer immunotherapy to overcome tumor metastasis.
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Células Asesinas Naturales/inmunología , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , MAP Quinasa Quinasa Quinasa 5/metabolismo , Metástasis de la Neoplasia/patología , Animales , Línea Celular , Línea Celular Tumoral , Femenino , Células HEK293 , Humanos , Inmunoterapia/métodos , Interferón gamma/metabolismo , Células Asesinas Naturales/metabolismo , Pulmón/inmunología , Pulmón/metabolismo , Pulmón/patología , Neoplasias Pulmonares/inmunología , Ratones , Ratones Endogámicos C57BL , Metástasis de la Neoplasia/inmunología , Células RAW 264.7RESUMEN
Cyclin-dependent kinases 4 and 6 (CDK4/6) inhibitors are considered a breakthrough in cancer therapy. Currently approved for breast cancer treatment, CDK4/6 inhibitors are extensively tested in other cancer subtypes. Frequently observed side effects include hematological abnormalities such as reduced numbers of neutrophils, erythroid cells and platelets that are associated with anemia, bleeding and a higher risk of infections. In order to understand whether the adverse effects within the hematopoietic system are related to CDK4 or CDK6 we generated transgenic mice that lack either CDK4 or CDK6 in adult hematopoiesis. Anemia and perturbed erythroid differentiation are associated with the absence of CDK6 but did not manifest in CDK4- deficient mice. Total CDK6 knockout mice accumulate the most dormant fraction of hematopoietic stem cells due to an impaired exit of the quiescent state. We recapitulated this finding by deleting CDK6 in adult hematopoiesis. In addition, unlike total CDK6 knockout, all stem cell fractions were affected and increased in numbers. The deletion of CDK6 was also accompanied by neutropenia which is frequently seen in patients receiving CDK4/6 inhibitors. This was not the case in the absence of CDK4; CDK4 deficiency resulted in elevated numbers of myeloid progenitors without translating into numeric changes of differentiated myeloid cells. By using Cdk4fl/fl and Cdk6fl/fl mice we assign side effects of CDK4/6 inhibitors predominantly to the absence of CDK6. These mice represent a novel and powerful tool that will enable to study the distinct functions of CDK4 and CDK6 in a tissue-dependent manner.
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Neoplasias de la Mama , Quinasa 4 Dependiente de la Ciclina , Quinasa 6 Dependiente de la Ciclina , Células Madre Hematopoyéticas , Animales , Quinasa 4 Dependiente de la Ciclina/genética , Quinasa 6 Dependiente de la Ciclina/genética , Femenino , Eliminación de Gen , Hematopoyesis/genética , Ratones , Ratones Noqueados , Ratones TransgénicosRESUMEN
We would like to thank Kancherla et al [...].
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Ácido Fólico , Defectos del Tubo Neural , Alimentos Fortificados , Humanos , NutrientesRESUMEN
Although group 3 innate lymphoid cells (ILC3s) are efficient inducers of T cell responses in the spleen, they fail to induce CD4+ T cell proliferation in the gut. The signals regulating ILC3-T cell responses remain unknown. Here, we show that transcripts associated with MHC II antigen presentation are down-modulated in intestinal natural cytotoxicity receptor (NCR)- ILC3s. Further data implicate microbiota-induced IL-23 as a crucial signal for reversible silencing of MHC II in ILC3s, thereby reducing the capacity of ILC3s to present antigen to T cells in the intestinal mucosa. Moreover, IL-23-mediated MHC II suppression is dependent on mTORC1 and STAT3 phosphorylation in NCR- ILC3s. By contrast, splenic interferon-γ induces MHC II expression and CD4+ T cell stimulation by NCR- ILC3s. Our results thus identify biological circuits for tissue-specific regulation of ILC3-dependent T cell responses. These pathways may have implications for inducing or silencing T cell responses in human diseases.
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Presentación de Antígeno/inmunología , Inmunidad Innata , Linfocitos/inmunología , Microbiota , Bazo/citología , Animales , Células Presentadoras de Antígenos/citología , Células Presentadoras de Antígenos/inmunología , Antígenos CD/metabolismo , Polaridad Celular , Regulación hacia Abajo , Antígenos de Histocompatibilidad Clase II/metabolismo , Interferón gamma/metabolismo , Interleucina-23/metabolismo , Activación de Linfocitos/inmunología , Linfocitos/citología , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Ratones , Microbiota/genética , Microbiota/inmunología , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Fenotipo , Fosforilación , Análisis de Componente Principal , Regiones Promotoras Genéticas/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Factor de Transcripción STAT3/metabolismo , Linfocitos T/inmunología , Transactivadores/genética , Transactivadores/metabolismo , Transcripción GenéticaRESUMEN
Aberrant activation of key signaling-molecules is a hallmark of acute myeloid leukemia (AML) and may have prognostic and therapeutic implications. AML summarizes several disease entities with a variety of genetic subtypes. A comprehensive model spanning from signal activation patterns in major genetic subtypes of pediatric AML (pedAML) to outcome prediction and pre-clinical response to signaling inhibitors has not yet been provided. We established a high-throughput flow-cytometry based method to assess activation of hallmark phospho-proteins (phospho-flow) in 166 bone-marrow derived pedAML samples under basal and cytokine stimulated conditions. We correlated levels of activated phospho-proteins at diagnosis with relapse incidence in intermediate (IR) and high risk (HR) subtypes. In parallel, we screened a set of signaling inhibitors for their efficacy against primary AML blasts in a flow-cytometry based ex vivo cytotoxicity assay and validated the results in a murine xenograft model. Certain phospho-signal patterns differ between genetic subtypes of pedAML. Some are consistently seen through all AML subtypes such as pSTAT5. In IR/HR subtypes high levels of GM-CSF stimulated pSTAT5 and low levels of unstimulated pJNK correlated with increased relapse risk overall. Combination of GM-CSF/pSTAT5high and basal/pJNKlow separated three risk groups among IR/HR subtypes. Out of 10 tested signaling inhibitors, midostaurin most effectively affected AML blasts and simultaneously blocked phosphorylation of multiple proteins, including STAT5. In a mouse xenograft model of KMT2A-rearranged pedAML, midostaurin significantly prolonged disease latency. Our study demonstrates the applicability of phospho-flow for relapse-risk assessment in pedAML, whereas functional phenotype-driven ex vivo testing of signaling inhibitors may allow individualized therapy.
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The United States implemented mandatory fortification of cereal grains with folic acid in 1998 to prevent neural tube defects (NTDs) during pregnancy. The health benefits of folate (vitamin B9) are well documented; however, there are potential risks of exceeding the upper tolerable limit, particularly in vulnerable populations. We conducted a population-based analysis of the Food Fortification Initiative dataset to determine the strength of the evidence regarding reports of decreased NTDs at the national level in response to mandatory folic acid fortification of cereal grains. We found a very weak correlation between NTD prevalence and the level of folic acid fortification, irrespective of the cereal grain fortified (wheat, maize or rice). Stratification of the data based on socioeconomic status (SES) indicated a strong linear relationship between reduced NTDs and better SES. We conclude that national fortification with folic acid is not associated with a significant decrease in the prevalence of NTDs at the population level.
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Grano Comestible , Ácido Fólico/administración & dosificación , Alimentos Fortificados , Defectos del Tubo Neural/prevención & control , Bases de Datos Factuales , Femenino , Humanos , Defectos del Tubo Neural/diagnóstico , Defectos del Tubo Neural/epidemiología , Embarazo , Prevalencia , Factores Protectores , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Determinantes Sociales de la Salud , Factores SocioeconómicosRESUMEN
BACKGROUND: Patients with signal transducer and activator of transcription 5b (STAT5b) deficiency have impairment in T-cell homeostasis and natural killer (NK) cells which leads to autoimmunity, recurrent infections, and combined immune deficiency. OBJECTIVE: In this study we characterized the NK cell defect in STAT5b-deficient human NK cells, as well as Stat5b-/- mice. METHODS: We used multiparametric flow cytometry, functional NK cell assays, microscopy, and a Stat5b-/- mouse model to elucidate the effect of impaired and/or absent STAT5b on NK cell development and function. RESULTS: This alteration generated a nonfunctional CD56bright NK cell subset characterized by low cytokine production. The CD56dim NK cell subset had decreased expression of perforin and CD16 and a greater frequency of cells expressing markers of immature NK cells. We observed low NK cell numbers and impaired NK cell maturation, suggesting that STAT5b is involved in terminal NK cell maturation in Stat5b-/- mice. Furthermore, human STAT5b-deficient NK cells had low cytolytic capacity, and fixed-cell microscopy showed poor convergence of lytic granules. This was accompanied by decreased expression of costimulatory and activating receptors. Interestingly, granule convergence and cytolytic function were restored after IL-2 stimulation. CONCLUSIONS: Our results show that in addition to the impaired terminal maturation of NK cells, human STAT5b mutation leads to impairments in early activation events in NK cell lytic synapse formation. Our data provide further insight into NK cell defects caused by STAT5b deficiency.
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Inmunidad Celular , Sinapsis Inmunológicas/inmunología , Células Asesinas Naturales/inmunología , Mutación , Factor de Transcripción STAT5/inmunología , Animales , Femenino , Humanos , Sinapsis Inmunológicas/genética , Células Asesinas Naturales/patología , Masculino , Ratones , Ratones Noqueados , Factor de Transcripción STAT5/genéticaRESUMEN
Recurrent gain-of-function mutations in the transcription factors STAT5A and much more in STAT5B were found in hematopoietic malignancies with the highest proportion in mature T- and natural killer-cell neoplasms (peripheral T-cell lymphoma, PTCL). No targeted therapy exists for these heterogeneous and often aggressive diseases. Given the shortage of models for PTCL, we mimicked graded STAT5A or STAT5B activity by expressing hyperactive Stat5a or STAT5B variants at low or high levels in the hematopoietic system of transgenic mice. Only mice with high activity levels developed a lethal disease resembling human PTCL. Neoplasia displayed massive expansion of CD8+ T cells and destructive organ infiltration. T cells were cytokine-hypersensitive with activated memory CD8+ T-lymphocyte characteristics. Histopathology and mRNA expression profiles revealed close correlation with distinct subtypes of PTCL. Pronounced STAT5 expression and activity in samples from patients with different subsets underline the relevance of JAK/STAT as a therapeutic target. JAK inhibitors or a selective STAT5 SH2 domain inhibitor induced cell death and ruxolitinib blocked T-cell neoplasia in vivo We conclude that enhanced STAT5A or STAT5B action both drive PTCL development, defining both STAT5 molecules as targets for therapeutic intervention.
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Leucemia , Linfoma de Células T Periférico , Animales , Linfocitos T CD8-positivos/metabolismo , Citocinas , Humanos , Linfoma de Células T Periférico/genética , Ratones , Factor de Transcripción STAT5/genética , Factor de Transcripción STAT5/metabolismo , Proteínas Supresoras de TumorRESUMEN
The cell dose in umbilical cord blood units is a major determinant for the outcome of hematopoietic cell transplantation. Prostaglandin analogs and dipeptidylpeptidase-4 (DPP4/CD26)-inhibitors enhance the ability of hematopoietic stem cells (HSCs) to reconstitute hematopoiesis. Here we explored the synergism between treprostinil, a stable prostaglandin agonist, and the DPP4/CD26-inhibitor vildagliptin. The combination of treprostinil and forskolin caused a modest but statistically significant increase in the surface levels of DPP4/CD26 on hematopoietic stem and progenitor cells (HSPCs) derived from murine bone and human cord blood. Their migration towards stromal cell-derived factor-1 (SDF-1/CXCL12) was enhanced, if they were pretreated with treprostinil and forskolin, and further augmented by vildagliptin. Administration of vildagliptin rescued 25% of lethally irradiated recipient mice injected with a limiting number of untreated HSPCs, but 90 to 100% of recipients injected with HSPCs preincubated with treprostinil and forskolin. The efficacy of vildagliptin surpassed that of treprostinil (60% rescue). Surprisingly, concomitant administration of vildagliptin and treprostinil resulted in poor survival of recipients indicating mutual antagonism, which was recapitulated when homing of and colony formation by HSPCs were assessed. These observations of regimen-dependent synergism and antagonism of treprostinil and vildagliptin are of translational relevance for the design of clinical trials. KEY MESSAGES: Pretreatment with treprostinil increases surface levels of DPP4/CD26 in HSPCs. Vildagliptin enhances in vitro migration of pretreated HSPCs. Vildagliptin enhances in vivo homing and engraftment of pretreated HSPCs. Unexpected mutual antagonism in vivo by concomitant administration of vildagliptin and treprostinil.
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Antihipertensivos/administración & dosificación , Inhibidores de la Dipeptidil-Peptidasa IV/administración & dosificación , Epoprostenol/análogos & derivados , Trasplante de Células Madre Hematopoyéticas , Vildagliptina/administración & dosificación , Animales , Células Cultivadas , Dipeptidil Peptidasa 4/metabolismo , Antagonismo de Drogas , Sinergismo Farmacológico , Epoprostenol/administración & dosificación , Sangre Fetal/citología , Células Madre Hematopoyéticas/efectos de los fármacos , Células Madre Hematopoyéticas/metabolismo , Humanos , RatonesRESUMEN
Cyclin-dependent kinases (CDKs) are frequently deregulated in cancer and represent promising drug targets. We provide evidence that CDK8 has a key role in B-ALL. Loss of CDK8 in leukemia mouse models significantly enhances disease latency and prevents disease maintenance. Loss of CDK8 is associated with pronounced transcriptional changes, whereas inhibiting CDK8 kinase activity has minimal effects. Gene set enrichment analysis suggests that the mTOR signaling pathway is deregulated in CDK8-deficient cells and, accordingly, these cells are highly sensitive to mTOR inhibitors. Analysis of large cohorts of human ALL and AML patients reveals a significant correlation between the level of CDK8 and of mTOR pathway members. We have synthesized a small molecule YKL-06-101 that combines mTOR inhibition and degradation of CDK8, and induces cell death in human leukemic cells. We propose that simultaneous CDK8 degradation and mTOR inhibition might represent a potential therapeutic strategy for the treatment of ALL patients.