RESUMEN
Adult T-cell leukemia/lymphoma (ATLL) is a mature T-cell lymphoproliferative disorder associated with the human T lymphotropic virus (HTLV-1) infection. ATLL predominantly affects individuals within HTLV-1 endemic areas such as Japan, areas of Africa, South America, and the Caribbean. HTLV-1 preferentially infects CD4+ T-cells, and several genetic hits must occur before ATLL develops. ATLL is classically divided into four clinical variants based on manifestations of disease: acute, chronic, lymphomatous, and smouldering. As of 2019, a new subtype has been described: lymphoma type of ATL, extranodal primary cutaneous. In this review, emphasis will be taken to describe the common clinicopathologic manifestations of the disease, advances in biomarker discovery, mutational landscape and targeted therapeutic approaches to treat this highly aggressive and frequently lethal type of T-cell lymphoma.
Asunto(s)
Leucemia-Linfoma de Células T del Adulto/patología , Biomarcadores de Tumor , Humanos , Ganglios Linfáticos/patología , Piel/patologíaRESUMEN
Ptpn6 is a cytoplasmic phosphatase that functions to prevent autoimmune and interleukin-1 (IL-1) receptor-dependent, caspase-1-independent inflammatory disease. Conditional deletion of Ptpn6 in neutrophils (Ptpn6∆PMN) is sufficient to initiate IL-1 receptor-dependent cutaneous inflammatory disease, but the source of IL-1 and the mechanisms behind IL-1 release remain unclear. Here, we investigate the mechanisms controlling IL-1α/ß release from neutrophils by inhibiting caspase-8-dependent apoptosis and Ripk1-Ripk3-Mlkl-regulated necroptosis. Loss of Ripk1 accelerated disease onset, whereas combined deletion of caspase-8 and either Ripk3 or Mlkl strongly protected Ptpn6∆PMN mice. Ptpn6∆PMN neutrophils displayed increased p38 mitogen-activated protein kinase-dependent Ripk1-independent IL-1 and tumor necrosis factor production, and were prone to cell death. Together, these data emphasize dual functions for Ptpn6 in the negative regulation of p38 mitogen-activated protein kinase activation to control tumor necrosis factor and IL-1α/ß expression, and in maintaining Ripk1 function to prevent caspase-8- and Ripk3-Mlkl-dependent cell death and concomitant IL-1α/ß release.
Asunto(s)
Apoptosis/inmunología , Caspasa 8/inmunología , Neutrófilos/inmunología , Proteínas Quinasas/inmunología , Proteína Tirosina Fosfatasa no Receptora Tipo 6/metabolismo , Proteína Serina-Treonina Quinasas de Interacción con Receptores/inmunología , Animales , Caspasa 8/genética , Células Cultivadas , Eliminación de Gen , Inflamación/inmunología , Interleucina-1/inmunología , Interleucina-1alfa/metabolismo , Interleucina-1beta/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Proteína Tirosina Fosfatasa no Receptora Tipo 6/genética , Receptores Tipo I de Interleucina-1/inmunología , Factor de Necrosis Tumoral alfa/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismoRESUMEN
Genetic modification of human leukemic cell lines using CRISPR-Cas9 has become a staple of gene-function studies. Single-cell cloning of modified cells is frequently used to facilitate studies of gene function. Inherent in this approach is an assumption that the genetic drift, amplified in some cell lines by mutations in DNA replication and repair machinery, as well as non-genetic factors will not introduce significant levels of experimental cellular heterogeneity in clones derived from parental populations. In this study, we characterize the variation in cell death of fifty clonal cell lines generated from human Jurkat and MOLT-4 T-cells edited by CRISPR-Cas9. We demonstrate a wide distribution of sensitivity to chemotherapeutics between non-edited clonal human leukemia T-cell lines, and also following CRISPR-Cas9 editing at the NLRP1 locus, or following transfection with non-targeting sgRNA controls. The cell death sensitivity profile of clonal cell lines was consistent across experiments and failed to revert to the non-clonal parental phenotype. Whole genome sequencing of two clonal cell lines edited by CRISPR-Cas9 revealed unique and shared genetic variants, which had minimal read support in the non-clonal parental population and were not suspected CRISPR-Cas9 off-target effects. These variants included genes related to cell death and drug metabolism. The variation in cell death phenotype of clonal populations of human T-cell lines may be a consequence of T-cell line genetic instability, and to a lesser extent clonal heterogeneity in the parental population or CRISPR-Cas9 off-target effects not predicted by current models. This work highlights the importance of genetic variation between clonal T-cell lines in the design, conduct, and analysis of experiments to investigate gene function after single-cell cloning.
Asunto(s)
Muerte Celular , Células Clonales , Linfocitos T/efectos de los fármacos , Antineoplásicos/farmacología , Línea Celular , Heterogeneidad Genética , Humanos , Quimioterapia de Inducción , Linfocitos T/patologíaRESUMEN
Neutrophil extracellular trap (NET) formation can generate short-term, functional anucleate cytoplasts and trigger loss of cell viability. We demonstrated that the necroptotic cell death effector mixed lineage kinase domain-like (MLKL) translocated from the cytoplasm to the plasma membrane and stimulated downstream NADPH oxidase-independent ROS production, loss of cytoplasmic granules, breakdown of the nuclear membrane, chromatin decondensation, histone hypercitrullination, and extrusion of bacteriostatic NETs. This process was coordinated by receptor-interacting protein kinase-1 (RIPK1), which activated the caspase-8-dependent apoptotic or RIPK3/MLKL-dependent necroptotic death of mouse and human neutrophils. Genetic deficiency of RIPK3 and MLKL prevented NET formation but did not prevent cell death, which was because of residual caspase-8-dependent activity. Peptidylarginine deiminase 4 (PAD4) was activated downstream of RIPK1/RIPK3/MLKL and was required for maximal histone hypercitrullination and NET extrusion. This work defines a distinct signaling network that activates PAD4-dependent NET release for the control of methicillin-resistant Staphylococcus aureus (MRSA) infection.
Asunto(s)
Apoptosis , Trampas Extracelulares/metabolismo , Neutrófilos/metabolismo , Proteínas Quinasas/metabolismo , Desiminasas de la Arginina Proteica/metabolismo , Animales , Caspasa 8/genética , Caspasa 8/metabolismo , Células Cultivadas , Trampas Extracelulares/genética , Histonas/metabolismo , Humanos , Staphylococcus aureus Resistente a Meticilina/fisiología , Ratones Endogámicos C57BL , Ratones Noqueados , Microscopía Electrónica de Transmisión , Neutrófilos/microbiología , Neutrófilos/ultraestructura , Proteínas Quinasas/genética , Arginina Deiminasa Proteína-Tipo 4 , Desiminasas de la Arginina Proteica/genética , Proteína Serina-Treonina Quinasas de Interacción con Receptores/genética , Proteína Serina-Treonina Quinasas de Interacción con Receptores/metabolismoRESUMEN
Immunological responses activated by pathogen recognition come in many guises. The proliferation, differentiation and recruitment of immune cells, and the production of inflammatory cytokines and chemokines are central to lifelong immunity. Cell death serves as a key function in the resolution of innate and adaptive immune responses. It also coordinates cell-intrinsic effector functions to restrict infection. Necrosis was formally considered a passive form of cell death or a consequence of pathogen virulence factor expression, and necrotic tissue is frequently associated with infection. However, there is now emerging evidence that points to a role for regulated forms of necrosis, such as pyroptosis and necroptosis, driving inflammation and shaping the immune response.
Asunto(s)
Apoptosis , Citotoxicidad Inmunológica , Animales , Bacterias/metabolismo , Caspasas/metabolismo , Trampas Extracelulares/metabolismo , Humanos , Inflamasomas/metabolismoRESUMEN
The mammalian target of rapamycin (mTOR) and phosphoinositide-3-kinase (PI3K) pathways are often aberrantly activated in acute myeloid leukemia (AML) and play critical roles in proliferation and survival of leukemia cells. We provide evidence that simultaneous targeting of mTOR complexes with the catalytic mTOR inhibitor OSI-027 and of the p110α subunit of PI3K with the specific inhibitor BYL-719 results in efficient suppression of effector pathways and enhanced induction of apoptosis of leukemia cells. Importantly, such a combined targeting approach results in enhanced suppression of primitive leukemic progenitors from patients with AML. Taken together, these findings raise the possibility of combination treatments of mTOR and p110α inhibitors as a unique approach to enhance responses in refractory AML.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Fosfatidilinositol 3-Quinasa Clase I/antagonistas & inhibidores , Imidazoles/farmacología , Leucemia Mieloide Aguda/tratamiento farmacológico , Inhibidores de las Quinasa Fosfoinosítidos-3 , Serina-Treonina Quinasas TOR/antagonistas & inhibidores , Tiazoles/farmacología , Triazinas/farmacología , Animales , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Fosfatidilinositol 3-Quinasa Clase I/metabolismo , Inhibidores Enzimáticos/administración & dosificación , Inhibidores Enzimáticos/farmacología , Humanos , Imidazoles/administración & dosificación , Leucemia Mieloide Aguda/enzimología , Fosfatidilinositol 3-Quinasas/metabolismo , Transducción de Señal , Serina-Treonina Quinasas TOR/genética , Serina-Treonina Quinasas TOR/metabolismo , Tiazoles/administración & dosificación , Triazinas/administración & dosificación , Células U937RESUMEN
Cutaneous T-cell lymphomas (CTCLs) represent a group of hematopoietic malignancies that home to the skin and have no known molecular basis for disease pathogenesis. Sézary syndrome (SS) is the leukemic variant of CTCL. Currently, CTCL is incurable, highlighting the need for new therapeutic modalities. We have previously observed that combined small-molecule inhibition of protein kinase C-ß (PKCß) and glycogen synthase kinase 3 (GSK3) causes synergistic apoptosis in CTCL cell lines and patient cells. Through microarray analysis of a SS cell line, we surveyed global gene expression following combined PKCß-GSK3 treatment to elucidate therapeutic targets responsible for cell death. Clinically relevant targets were defined as genes differentially expressed in SS patients that were modulated by combination-drug treatment of SS cells. Gene set enrichment analysis uncovered candidate genes enriched for an immune-cell signature, specifically the T-cell receptor and mitogen-activated protein kinase signaling pathways. Further analysis identified p38 as a potential therapeutic target that is overexpressed in SS patients and decreased by synergistic-inhibitor treatment. This target was verified through small-molecule inhibition of p38, leading to cell death in both SS cell lines and patient cells. These data establish p38 as a SS biomarker and a potential therapeutic target for the treatment of CTCL.
Asunto(s)
Proteína Quinasa 11 Activada por Mitógenos/antagonistas & inhibidores , Síndrome de Sézary/tratamiento farmacológico , Neoplasias Cutáneas/tratamiento farmacológico , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Glucógeno Sintasa Quinasa 3/antagonistas & inhibidores , Humanos , Sistema de Señalización de MAP Quinasas , Proteína Quinasa C beta/antagonistas & inhibidores , Síndrome de Sézary/patología , Neoplasias Cutáneas/patologíaRESUMEN
The mechanism by which cells decide to skip mitosis to become polyploid is largely undefined. Here we used a high-content image-based screen to identify small-molecule probes that induce polyploidization of megakaryocytic leukemia cells and serve as perturbagens to help understand this process. Our study implicates five networks of kinases that regulate the switch to polyploidy. Moreover, we find that dimethylfasudil (diMF, H-1152P) selectively increased polyploidization, mature cell-surface marker expression, and apoptosis of malignant megakaryocytes. An integrated target identification approach employing proteomic and shRNA screening revealed that a major target of diMF is Aurora kinase A (AURKA). We further find that MLN8237 (Alisertib), a selective inhibitor of AURKA, induced polyploidization and expression of mature megakaryocyte markers in acute megakaryocytic leukemia (AMKL) blasts and displayed potent anti-AMKL activity in vivo. Our findings provide a rationale to support clinical trials of MLN8237 and other inducers of polyploidization and differentiation in AMKL.
Asunto(s)
Azepinas/farmacología , Descubrimiento de Drogas , Leucemia Megacarioblástica Aguda/tratamiento farmacológico , Megacariocitos/metabolismo , Poliploidía , Pirimidinas/farmacología , Bibliotecas de Moléculas Pequeñas , 1-(5-Isoquinolinesulfonil)-2-Metilpiperazina/análogos & derivados , 1-(5-Isoquinolinesulfonil)-2-Metilpiperazina/farmacología , Animales , Aurora Quinasa A , Aurora Quinasas , Diferenciación Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Humanos , Leucemia Megacarioblástica Aguda/genética , Megacariocitos/citología , Megacariocitos/patología , Ratones , Ratones Endogámicos C57BL , Mapas de Interacción de Proteínas , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Proteínas Serina-Treonina Quinasas/metabolismo , Quinasas Asociadas a rho/metabolismoRESUMEN
Individuals with Down syndrome (DS; also known as trisomy 21) have a markedly increased risk of leukemia in childhood but a decreased risk of solid tumors in adulthood. Acquired mutations in the transcription factor-encoding GATA1 gene are observed in nearly all individuals with DS who are born with transient myeloproliferative disorder (TMD), a clonal preleukemia, and/or who develop acute megakaryoblastic leukemia (AMKL). Individuals who do not have DS but bear germline GATA1 mutations analogous to those detected in individuals with TMD and DS-AMKL are not predisposed to leukemia. To better understand the functional contribution of trisomy 21 to leukemogenesis, we used mouse and human cell models of DS to reproduce the multistep pathogenesis of DS-AMKL and to identify chromosome 21 genes that promote megakaryoblastic leukemia in children with DS. Our results revealed that trisomy for only 33 orthologs of human chromosome 21 (Hsa21) genes was sufficient to cooperate with GATA1 mutations to initiate megakaryoblastic leukemia in vivo. Furthermore, through a functional screening of the trisomic genes, we demonstrated that DYRK1A, which encodes dual-specificity tyrosine-(Y)-phosphorylation-regulated kinase 1A, was a potent megakaryoblastic tumor-promoting gene that contributed to leukemogenesis through dysregulation of nuclear factor of activated T cells (NFAT) activation. Given that calcineurin/NFAT pathway inhibition has been implicated in the decreased tumor incidence in adults with DS, our results show that the same pathway can be both proleukemic in children and antitumorigenic in adults.