RESUMEN
Dose-limiting toxicity poses a major limitation to the clinical utility of targeted cancer therapies, often arising from target engagement in nonmalignant tissues. This obstacle can be minimized by targeting cancer dependencies driven by proteins with tissue-restricted and/or tumor-restricted expression. In line with another recent report, we show here that, in acute myeloid leukemia (AML), suppression of the myeloid-restricted PIK3CG/p110γ-PIK3R5/p101 axis inhibits protein kinase B/Akt signaling and compromises AML cell fitness. Furthermore, silencing the genes encoding PIK3CG/p110γ or PIK3R5/p101 sensitizes AML cells to established AML therapies. Importantly, we find that existing small-molecule inhibitors against PIK3CG are insufficient to achieve a sustained long-term antileukemic effect. To address this concern, we developed a proteolysis-targeting chimera (PROTAC) heterobifunctional molecule that specifically degrades PIK3CG and potently suppresses AML progression alone and in combination with venetoclax in human AML cell lines, primary samples from patients with AML and syngeneic mouse models.
Asunto(s)
Fosfatidilinositol 3-Quinasa Clase Ib , Leucemia Mieloide Aguda , Proteínas Proto-Oncogénicas c-akt , Transducción de Señal , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/genética , Humanos , Animales , Ratones , Transducción de Señal/efectos de los fármacos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Fosfatidilinositol 3-Quinasa Clase Ib/metabolismo , Fosfatidilinositol 3-Quinasa Clase Ib/genética , Línea Celular Tumoral , Ensayos Antitumor por Modelo de Xenoinjerto , Sulfonamidas/farmacología , Sulfonamidas/uso terapéutico , Proteolisis/efectos de los fármacos , Femenino , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Compuestos Bicíclicos Heterocíclicos con Puentes/uso terapéuticoRESUMEN
Innovative strategies for enhancing efficacy and overcoming drug resistance in hematologic cancers, such as using antibody-drug conjugates (ADC), have shifted the paradigm of conventional care by delivering promising outcomes in cancer therapies with a significant reduction in the risk of relapse. Transferrin receptor (TfR1), cluster of differentiation 71 (CD71), is known to be overexpressed in malignant cells and considered a potent antitumor target. Therefore, we developed an anti-CD71 ADC, INA03, a humanized antibody conjugated to monomethyl auristatin E through a 3-arylpropiolonitrile-valine-citrulline linker. In this study, we investigated the potency and safety of INA03, in competition with Transferrin (Tf), the CD71's natural ligand, as a novel strategy to specifically target highly proliferative cells. The high expression of CD71 was confirmed on different leukemic cell lines, allowing INA03 to bind efficiently. Subsequently, INA03 rapidly internalizes into lysosomal compartments, in which its cytotoxic drug is released following cathepsin B cleavage. Downregulation of CD71 expression using shRNA highlighted that INA03-induced cell death was dependent on CD71 density at the cell surface. INA03 intravenous treatment in acute leukemia mouse models significantly reduced tumor burden, increased mouse survival, and showed no residual disease compared with conventional chemotherapies. Because INA03 competes with human Tf, a double knock-in (human CD71/human Tf) competent mouse model was generated to mimic human pharmacokinetics and pharmacodynamics. INA03 administration in human CD71/hTf mice did not reveal any improper toxicities, even at high doses. Hence, these data demonstrate the promising preclinical efficacy and safety of INA03 and support its development as a novel acute leukemia treatment. Significance: The Tf receptor is believed to be undruggable because of its ubiquitous expression. By entering into competition with its cognate ligand, the Tf and INA03 ADC can safely achieve potency.
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Antígenos CD , Inmunoconjugados , Receptores de Transferrina , Transferrina , Humanos , Animales , Ratones , Receptores de Transferrina/metabolismo , Receptores de Transferrina/antagonistas & inhibidores , Inmunoconjugados/farmacología , Inmunoconjugados/uso terapéutico , Antígenos CD/metabolismo , Transferrina/metabolismo , Ensayos Antitumor por Modelo de Xenoinjerto , Línea Celular Tumoral , Leucemia/tratamiento farmacológico , Leucemia/patología , FemeninoRESUMEN
Comparative clinical characteristics, molecular landscape and prognosis scoring for primary (PMF) and secondary myelofibrosis (SMF).
Asunto(s)
Mielofibrosis Primaria , Humanos , Mielofibrosis Primaria/genética , PronósticoRESUMEN
Current recommended risk scores to predict thrombotic events associated with myeloproliferative neoplasms (MPN) do not discriminate between arterial and venous thrombosis despite their different physiopathology. To define novel stratification systems, we delineated a comprehensive landscape of MPN associated thrombosis across a large long-term follow-up MPN cohort. Prior arterial thrombosis, age >60 years, cardiovascular risk factors and presence of TET2 or DNMT3A mutations were independently associated with arterial thrombosis in multivariable analysis. ARTS, an ARterial Thrombosis Score, based on these four factors, defined low- (0.37% patients-year) and high-risk (1.19% patients-year) patients. ARTS performance was superior to the two-tiered conventional risk stratification in our training cohort, across all MPN subtypes, as well as in two external validation cohorts. Prior venous thrombosis and presence of a JAK2V617F mutation with a variant allelic frequency ≥50% were independently associated with venous thrombosis. The discrimination potential of VETS, a VEnous Thrombosis Score based on these two factors, was poor, similar to the two-tiered conventional risk stratification. Our study pinpoints arterial and venous thrombosis clinico-molecular differences and proposes an arterial risk score for more accurate patients' stratification. Further improvement of venous risk scores, accounting for additional factors and considering venous thrombosis as a heterogeneous entity is warranted.
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Trastornos Mieloproliferativos , Neoplasias , Trombosis , Trombosis de la Vena , Humanos , Persona de Mediana Edad , Neoplasias/complicaciones , Trombosis de la Vena/genética , Trombosis/genética , Trombosis/complicaciones , Mutación , Trastornos Mieloproliferativos/complicaciones , Trastornos Mieloproliferativos/genética , Factores de Riesgo , Janus Quinasa 2/genética , Medición de RiesgoAsunto(s)
Compuestos Bicíclicos Heterocíclicos con Puentes/administración & dosificación , Amiloidosis de Cadenas Ligeras de las Inmunoglobulinas/tratamiento farmacológico , Sulfonamidas/administración & dosificación , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Amiloidosis de Cadenas Ligeras de las Inmunoglobulinas/diagnóstico , Amiloidosis de Cadenas Ligeras de las Inmunoglobulinas/genética , Masculino , Persona de Mediana Edad , Estudios RetrospectivosRESUMEN
Over the past decades, genetic advances have allowed a more precise molecular characterization of AML with the identification of novel oncogenes and tumor suppressors as part of a comprehensive AML molecular landscape. Recent advances in genetic sequencing tools also enabled a better understanding of AML leukemogenesis from the preleukemic state to posttherapy relapse. These advances resulted in direct clinical implications with the definition of molecular prognosis classifications, the development of treatment recommendations based on minimal residual disease (MRD) measurement and the discovery of novel targeted therapies, ultimately improving AML patients' overall survival. The more recent development of functional genomic studies, pushed by novel molecular biology technologies (short hairpin RNA (shRNA) and CRISPR-Cas9) and bioinformatics tools design on one hand, along with the engineering of humanized physiologically relevant animal models on the other hand, have opened a new genomics era resulting in a greater knowledge of AML physiopathology. Combining descriptive and functional genomics will undoubtedly open the road for an AML cure within the next decades.
RESUMEN
BACKGROUND: Preventing premature ovarian failure (POF) is a major challenge in oncology. With conventional regimens, cytotoxicity-associated POF involves primordial follicles (PF) pool depletion by apoptosis or overactivation mechanisms, notably mediated by the ABL/TAp63 and PI3K/Akt/mTOR pathways. New anticancer treatments have been designed to target pathways implicated in tumor growth. Although concerns regarding fertility arise with these targeted therapies, we hypothesized that targeted therapies may exert off-tumor effects on PF that might delay POF. We provide an overview of evidence concerning these off-tumor effects on PF. Limitations and future potential implications of these findings are discussed. DESIGN: PubMed was searched by combining Boolean operators with the following keywords: fertility, ovarian, follicle, anti-tumoral, cancer, targeted, cytotoxic, and chemotherapy. RESULTS: Cisplatin-related PF apoptosis via the ABL/TAp63 pathway was targeted with a tyrosine kinase inhibitor, imatinib, in mice, but effects were recently challenged by findings on human ovarian xenografts in mice. In cyclophosphamide-treated mice, PI3K/Akt/mTOR pathway inhibition with mTOR inhibitors and AS101 preserved the PF pool. Proteasome and GSK3 inhibitors were evaluated for direct and indirect follicle DNA damage prevention. Surprisingly, evidence for cytotoxic drug association with PF pool preservation was found. We also describe selected non-anticancer molecules that may minimize gonadotoxicity. CONCLUSION: Not all anticancer treatments are associated with POF, particularly since the advent of targeted therapies. The feasibility of associating a protective drug targeting PF exhaustion mechanisms with cytotoxic treatments should be evaluated, as a way of decreasing the need for conventional fertility preservation techniques. Further evaluations are required for transfer into clinical practice. IMPLICATIONS FOR PRACTICE: Anticancer therapies are associated with infertility in 10%-70% of patients, which is the result of primordial follicles pool depletion. Alone or associated with gonadotoxic treatments, some targeted therapies may exert favorable off-targets effects on the primordial follicle pool by slowing down their exhaustion. Current evidence of these effects relies on murine models or human in vitro models. Evaluation of these protective strategies in humans is challenging; however, if these results are confirmed with clinical and biological data, it not only could be a new approach to female fertility preservation but also would change standard fertility strategies.