RESUMEN
NR4A3 is a key tumor suppressor in myeloid malignancy, mice lacking both NR4A1 and family member NR4A3 rapidly develop lethal acute myeloid leukemia (AML). We identified a long non-coding transcript in the NR4A3 locus and pursued the characterization of this anonymous transcript and the study of its role in leukemogenesis. We characterized this novel long non-coding transcript as a sense polyadenylated transcript. Bone marrow cells from AML patients expressed significantly reduced levels of lncNR4A3 compared to healthy controls (controls = 15, MDS= 20, p=0.05., AML= 21, p<0.01). Expression of NR4A3, as previously reported, was also significantly reduced in AML. Interestingly, the expression of both coding and non-coding transcripts was highly correlated (Pearson R = 0.3771, P<0.01). Transient over-expression of LncNR4A3 by nucleofection led to an increase in the RNA and protein level of NR4A3, reduction of proliferation in myeloid cell lines K-562 and KG1 (n=3 and 2 respectively, p<0.05) and reduced colony formation capacity in primary leukemic cells. A mass spectrometry-based quantitative proteomics approach was used to identify proteins dysregulated after lncNR4A3 over-expression in K-562. Enrichment analysis showed that the altered proteins are biologically connected (n=4, p<0.001) and functionally associated to RNA binding, transcription elongation, and splicing. Remarkably, we were able to validate the most significant results by WB. We showed that this novel transcript, lncNR4A3 regulates NR4A3 and we hypothesize this regulatory mechanism is mediated by the modulation of the RNA processing machinery.
RESUMEN
LEF1 antisense RNA 1 (LEF1-AS1) is an antisense long non-coding RNA encoded in the lymphoid enhancer-binding factor 1 (LEF1) locus. LEF1-AS1 is a conserved transcript dysregulated in hematopoiesis. This study aimed to functionally characterize the role of this transcript in myeloid malignancy and explore a possible regulatory effect of LEF1-AS1 upon LEF1. We show that LEF1-AS1 is highly expressed in normal hematopoietic stem cells but barely detectable in myeloid malignant cell lines. Additionally, bone marrow cells from myelodysplastic syndrome (n=12) and acute myeloid malignancy patients (n=28) expressed significantly reduced levels of LEF1-AS1 compared to healthy controls (n=15). Artificial LEF1-AS1 over-expression inhibited proliferation in HL60 and led to an upregulation of tumor suppressors p21 and p27, and reduced ERK1/2 activation. Unexpectedly, no underlying modulation of LEF1 was detected. Ectopic expression of LEF1-AS1 also inhibited proliferation in HELA, a cell line lacking endogenous expression of LEF1, supporting a LEF1-independent mechanism. Additionally, transient over-expression of LEF1-AS1 in AML patient cells also led to reduced proliferation and colony formation capacity. We used a mass spectrometry-based proteomics approach. Proteomic quantification identified the modulation of an important metabolic regulator, Fumarase, and concomitant accumulation of the metabolite fumarate.
Asunto(s)
Proliferación Celular , Regulación Neoplásica de la Expresión Génica , Leucemia Mieloide Aguda/patología , Factor de Unión 1 al Potenciador Linfoide/metabolismo , Síndromes Mielodisplásicos/patología , ARN Largo no Codificante/genética , Estudios de Casos y Controles , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Factor de Unión 1 al Potenciador Linfoide/genética , Síndromes Mielodisplásicos/genética , Síndromes Mielodisplásicos/metabolismo , Pronóstico , Tasa de Supervivencia , Células Tumorales CultivadasRESUMEN
La predisposición de algunas familias a padecer hemopatías mieloides malignas ha sido descrita desde hace varias décadas; sin embargo, solo recientemente ha sido posible conocer las bases moleculares de estos síndromes. La importancia de reconocer y diagnosticar la presencia de mutaciones predisponentes de la línea germinal en pacientes con hemopatías malignas y en sus familiares determinó que la Organización Mundial de la Salud (OMS) introdujera esta nueva categoría en su última revisión de la clasificación de las neoplasias malignas y leucemias agudas. Mediante el uso de las modernas técnicas de biología molecular se ha logrado el descubrimiento de mutaciones en diferentes genes que aportan nuevos elementos en el proceso de leucemogénesis, permiten ofrecer consejo genético, una mejor selección del donante de médula ósea y se erigen en la fuente de futuras dianas terapéuticas. En este trabajo se revisan algunos de los síndromes de hemopatías mieloides malignas hereditarias (HMMH) y se enfatiza en la necesidad de realizar una exhaustiva historia clínica personal y familiar que permita un elevado índice de sospecha para el diagnóstico de estas entidades(AU)
The familial predisposition to inherited myeloid malignancies has been described since several decades ago; however, only recently have been possible to known the molecular basis of these syndromes. The importance to recognize and diagnosed predisposing germ line mutations in patients and relatives contributed to the introduction of this new category in the latest update of myeloid neoplasm and acute leukemia by World Health Organization (WHO). The use of modern molecular biology techniques has achieved the discovery of genetic mutations that shed light inside leukemogenesis process, allow offering a genetic counseling, a better donor selection and are the basis of future therapeutics targets. The main hereditary myeloid malignancy syndromes (IMMS) are reviewed, emphasizing the need of exhaustive personal and family clinical history and to have a high suspicion index to diagnose these entities(AU)
Asunto(s)
Humanos , Masculino , Femenino , Trasplante de Células Madre Hematopoyéticas/métodos , Neoplasias Hematológicas/diagnóstico , Neoplasias Hematológicas/genética , Registros Médicos/normas , Mutación de Línea Germinal/genéticaRESUMEN
La predisposición de algunas familias a padecer hemopatías mieloides malignas ha sido descrita desde hace varias décadas; sin embargo, solo recientemente ha sido posible conocer las bases moleculares de estos síndromes. La importancia de reconocer y diagnosticar la presencia de mutaciones predisponentes de la línea germinal en pacientes con hemopatías malignas y en sus familiares determinó que la Organización Mundial de la Salud (OMS) introdujera esta nueva categoría en su última revisión de la clasificación de las neoplasias malignas y leucemias agudas. Mediante el uso de las modernas técnicas de biología molecular se ha logrado el descubrimiento de mutaciones en diferentes genes que aportan nuevos elementos en el proceso de leucemogénesis, permiten ofrecer consejo genético, una mejor selección del donante de médula ósea y se erigen en la fuente de futuras dianas terapéuticas. En este trabajo se revisan algunos de los síndromes de hemopatías mieloides malignas hereditarias (HMMH) y se enfatiza en la necesidad de realizar una exhaustiva historia clínica personal y familiar que permita un elevado índice de sospecha para el diagnóstico de estas entidades(AU)
The familial predisposition to inherited myeloid malignancies has been described since several decades ago; however, only recently have been possible to known the molecular basis of these syndromes. The importance to recognize and diagnosed predisposing germ line mutations in patients and relatives contributed to the introduction of this new category in the latest update of myeloid neoplasm and acute leukemia by World Health Organization (WHO). The use of modern molecular biology techniques has achieved the discovery of genetic mutations that shed light inside leukemogenesis process, allow offering a genetic counseling, a better donor selection and are the basis of future therapeutics targets. The main hereditary myeloid malignancy syndromes (IMMS) are reviewed, emphasizing the need of exhaustive personal and family clinical history and to have a high suspicion index to diagnose these entities(AU)