Trasplante alogénico en leucemia mieloide aguda y la importancia genética en desarrollo de nuevos tratamientos / Allological transplant in acute myeloid leukemia, the genetic importance for the development of new treatments

La Leucemia Mieloide Aguda es una enfermedad caracterizada por la alteración en la producción de células madre hematopoyéticas y la proliferación celular. Es más común en adultos; a pesar de ello solo se presenta en el 1 % en los Estados Unidos. Entre los 65-68 años se observa una mayor incidencia existiendo de 2-3 casos por cada año en 100.000 habitantes, siendo aproximadamente el 10 % de los cánceres de este tipo. Los diagnósticos más recomendados para esta enfermedad son los de carácter sanguíneo, la realización de citometrías de flujo en muestra de médula ósea. Según estudios, los análisis citogenéticos en un gran número de pacientes han demostrado translocaciones e inversiones en los cromosomas somáticos, mientras que solo una minoría tiene una organización de cromosomas somáticos balanceada. La terapia de consolidación se acompaña del trasplante de células madre hematopoyéticas, conocido como el trasplante alogénico, que puede ser potencialmente curativo en algunos pacientes.

The acute myeloid leukemia, is a disease which is a characterized by an irregular production of hematopoietic cells and cellular proliferation. It´s most common in adults, however only 1% of American adults will be diagnosed throughout their lives. Between the ages of 65-68 there is a high incidence with only 2-3 cases per 100.000 patients; making up only 10% of this type of cancer. It´s mainly diagnosed by using blood test, flow cytometry (on Bone Marrow samples). Some cytogenetic studies suggest that in a significant number of patients both somatic chromosomal inversion and translocation are present, while only a small percentage show no somatic chromosomal mutations. Consolidation therapy with a hematopoietic Stem Cells transplant, also known as a "allogenic transplant", can be potentially curative in some special cases.

Diagnostic et évaluation de la réponse thérapeutique de la leucémie myéloïde chronique au Mali par l'hybridation in situ fluorescente / Diagnosis and evaluation of the response to treatment of chronic myeloid leukaemia in Mali by fluorescent in situ hybridization

La leucémie myéloïde chronique (LMC) est une hémopathie maligne caractérisée par la présence du chromosome Philadelphie ou du gène de fusion BCR/ABL1. Au Mali, les approches génétiques de diagnostic et d'évaluation de la réponse thérapeutique de la LMC font défaut d'où l'intérêt de développer la méthode FISH (Hybridation in situ en Fluorescence) pour diagnostiquer et évaluer la réponse thérapeutique de la LMC. Méthodes. Nous avons analysé les cellules sanguines de 25 patients référés pour diagnostic ou évaluation thérapeutique de la LMC. Nous avons réalisé la FISH sur des cellules interphasiques et des métaphases, et la capture d'images cellulaires a été faite avec un microscope à épifluorescence. Résultats. Au total, 25 patients ont été inclus dont 16 pour diagnostic et 9 pour évaluation thérapeutique. Nous avons obtenu un taux de succès de 92% pour l'obtention des métaphases. En outre, nous avons observé des réarrangements ABL1/BCR à la FISH chez 22 des 25 patients. Parmi ces 22 patients, 16 ont présenté un patron de signaux typiques et 6 des patrons de signaux atypiques. Conclusion. Nous avons établi la technique FISH au Mali pour le diagnostic et l'évaluation thérapeutique de la LMC et identifié des formes atypiques de la translocation t(9 ;22).

Objective. Chronic myeloid leukemia (CML) is a hematologic malignancy characterized by the presence of the Philadelphia chromosome or its molecular equivalent, the BCR/ABL1 fusion gene. Diagnosis and monitoring of CML are done by detecting this chromosome, the BCR/ABL1 gene, or the BCR/ABL1 transcript. In Mali, genetic tools of diagnosis and follow-up are still lacking, so we did this study with the objectives of developing the FISH technique to diagnose, to follow up, and to characterize the cytogenetic profile of CML patients. Methods. We carried out FISH technique by using the dual color dual fusion probe for BCR/ABL1 on interphase nuclei and metaphases. Slides were scanned with an epifluorescence microscope. Results. A total of 25 patients (16 for diagnostic and 9 for follow-up) were included. We achieved a 92% success rate for obtaining metaphases. The BCR/ABL1 gene fusion signal was present in 22 patients. Among those 22 patients, 16 presented a typical signal pattern and 6 presented atypical signal patterns. Conclusion. We set up the FISH technique in Mali for the diagnosis and the follow-up of CML patients and identified atypical translocation of t(9;22).

Leucemia monoblastica aguda: complicaciones y respuesta a la quimioterapia de inducción. Reporte de cado / Acute monoblastic leukemia: complications and response to induction chemotherapy. Case report

La leucemia Monoblástica o Monocítica Aguda, es similar a otros subtipos de leucemias agudas, algunas peculiaridades que las diferencian son la hiperleucocitosis, infiltración extramedular y coagulación intravascular diseminada. El tratamiento de inducción se basa en drogas antracíclicas combinadas con citarabina; las complicaciones pueden ser fatales y la sobrevida a largo plazo se estima en 25% a 40%. Objetivo: documentar la r espuesta y complicaciones del tratamiento (quimioterapia) de inducción en la leucemia monoblástica aguda. Presentación de caso clínico: mujer de 34 años, acude con cuadr o inicial de congestión nasal bilateral y fiebre; examen físico normal, a excepción de equimosis en sitios de venopunción, el hemograma reveló anemia, leucocitosis y trombocitopenia. El frotis de sangre periférica, la biopsia y aspirado de médula ósea, fueron característicos de leucemia mieloide aguda tipo monocítica. Durante el tratamiento se administró dos ciclos de quimioterapia de inducción y coadyuvantes con base en hemoderivados, factor estimulante de colonias de granulocitos, antieméticos, antibióticos y antimicóticos. Complicaciones: se presentó toxicidad manifiesta por náuseas y vómitos grado II, mucositis, pérdida de peso y alopecia total, alteraciones hematológicas y complicaciones infecciosas grado IV. Se obtuvo remisión hematológica completa. Conclusión: es posible tr atar pacientes que sufr en leucemia monoblástica aguda tipo M5, en nuestro 1Universidad Nacional Autónoma de Honduras, Facultad de Ciencias Médicas, Tegucigalpa, Honduras. 2Laboratorios Molina, Tegucigalpa, Honduras. 3Investigador Independiente, Western International School, San Pedro Sula, Honduras. Autor de correspondencia: José Angel Sánchez N., jose.skiro@gmail.com Recibido: 03/12/2020 Aceptado: 15/05/2021 medio, con quimioterapia agresiva y obtener remisión hematológica completa. La identificación temprana de complicaciones y manejo oportuno es fundamental para evitar consecuencias fatales...(AU)

Effect of DR4 Demethylation to the Proliferation and Apoptosis of Myeloid Leukemia K562 Cells / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect of tumor necrosis factor death receptor (DR) 4 demethylation to the proliferation and apoptosis of myeloid leukemia K562 cells.@*METHODS@#The logarithmic phase of K562 cells were treated by desitabine (DCA) at 0, 0.8, 1.6 and 3.2 μmol/L, and the cells were divided into control group, DCA low dose group, DCA medium dose group and DCA high dose group respectively. The cells in control group were treated by tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) 0.5 μg/ml for 24 h, and the cells were divided into TRAIL group. The cells in DCA high dose group were treated by TRAIL 0.5 μg/ml for 24 h, and were divided into DCA high dose + TRAIL group. Methylation-specific polymerase chain reaction (MS-PCR) was used to measure the methylation status of the DR4 gene promoter in the control group and DCA low, medium and high dose groups. Real-time fluorescent quantitative polymerase chain reaction (qRT-PCR) and Western blot were used to determine the relative expression of DR4 mRNA and protein in the control group and DCA low, medium and high dose groups. Dime- thylthiazole (MTT) method was used to determine the inhibition rate of cell proliferation of the cells in control group, DCA high dose group, TRAIL group, DCA high dose + TRAIL group. Flow cytometry was used to determine the apoptotic rate of the cells in control group, DCA high dose group, TRAIL group, DCA high dose + TRAIL group.@*RESULTS@#The cells in the control group were methylation-positive, the brightness of the methylation bands of the cells in the DCA low, medium, and high dose groups was gradually decreased to disappear, and the DCA high dose group showed negative for methylation. The relative expression of DR4 mRNA and protein in the control group, DCA low, medium and high dose groups was increased sequentially (r=0.624, 0.704). The inhibition rate of cell proliferation of the cells in the control group, DCA high dose group, TRAIL group, DCA high dose + TRAIL group was increased sequentially (r=0.653, 0.754, 0.709, 0.725) at 24, 48 and 72 h.@*CONCLUSION@#DCA can reverse the methylation level of DR4 gene promoter in ML K562 cells and up-regulate the expression of DR4, which may enhance the proliferation inhibition and apoptosis promotion effects of TRAIL on K562 cells.

Inhibitory effect of PI3Kδ inhibitor idelalisib on proliferation of human myeloid leukemia cells and the reversal effect on drug resistance to adriamycin / 中南大学学报(医学版)

OBJECTIVES@#To investigate the effect of adriamycin (ADM), idelalisib or ADM and their combination on cell proliferation and intracellular concentration of ADM, and to explore the reversal effect of idelalisib on drug resistance to ADM.@*METHODS@#The K562 and K562/ADM cells were respectively treated with ADM and idelalisib at different concentrations. The 50% inhibitory concentration (IC@*RESULTS@#The cell survival rates were significantly decreased in a dose-dependent manner when the cells were treated with different doses of ADM (0.001-10.000 mg/L ). The IC@*CONCLUSIONS@#Idelalisib exerts effect on inhibition of the proliferation in myeloid leukemia K562 and K562/ADM cells, which may partially reverse the drug resistance of K562/ADM cells to ADM. The mechanisms for the effect of idelalisib may be related to increasing the accumulation of ADM and inducing the cell apoptosis in the K562 and K562/ADM cells.

Interaction between PSF and cytokeratin 18 mediates PSF relocation to cell membrane and maintains chemosensitivity of myeloid leukemia / 北京大学学报(医学版)

OBJECTIVE@#To identify the chaperone of polypyrimidine tractor-binding protein-associated splicing factor (PSF) in myeloid leukemia cells, and to explore the mechanism and redistributive pattern to cell surface of PSF in chemo-sensitive HL60 cells and resistant HL60/DOX cells.@*METHODS@#The eukaryotic expression vector of PSF was transfected with liposomes transiently, then flow cytometry was used to detect the expression level of PSF on the cell surface 24 h, 48 h and 72 h after vector transfections. We constructed a chimeric expression vector, streptavidin binding peptide (SBP)-PSF, meanwhile this vector was transfected and made SBP-PSF fusion protein overexpress. In addition, we used streptavidin magnetic beads to precipitate the cellular chaperonin of PSF and then identified its chaperonin by mass spectrometry (MS). Lentiviral vectors containing cytokeratin18 (K18) interference sequences were transfected into 293T cells to prepare lentivirus. HL60 and HL60/DOX cells were infected with lentivirus to obtain stable interfering K18 cell lines. Next, flow cytometry was used to test the membrane relocation level of PSF. Together, these methods confirmed the similar or different mechanisms of the PSF redistributing to membrane synergistically mediated by K18 in HL60 and HL60/DOX cells.@*RESULTS@#The expression of membrane relocated PSF was detected every day for three days (at the end of 24 h, 48 h and 72 h) after transient overexpression. The expressing rate of PSF on the cell surface was 22.4%±3.5%, 37.9%±6.0%, 58.3%±8.8%, respectively in sensitive HL60 cells, while that was 4.7%±0.5%, 3.9%±0.6%, 2.9%±0.6% , respectively in resistant HL60/DOX cells. The difference of expressing rate on each day was significant, P<0.01. We identified K18 detected by co-immunoprecipitation and mass spectrum assay which was the cellular chaperone of PSF. We found that K18 knockdown decreased the PSF expression level which redistributed on cell surface from 48.9%±5.4% to 6.2%±1.0% in sensitive HL60 cells, and from 9.11%±1.2% to 2.21%±0.51% in resistant HL60/DOX cells, respectively.@*CONCLUSION@#K18 is the intracellular chaperonin of PSF. The interaction of PSF and K18 mediates its redistribution to cell membrane in sensitive cells. While in resistant cells, PSF failed to relocate at the cell surface and accumulated in cells, which mediated resistance to chemotherapeutics.

Inclusões semelhantes aos corpúsculos de Russell em blastos mieloides / Inclusions similar to Russell bodies in myeloblasts

Alterações nos mecanismos celulares resultam no aparecimento de corpúsculos de Russel, que são inclusões intracitoplasmáticas basofílicas. Estas inclusões ocorrem devido a uma indigestão celular de proteínas e podem ser observadas em diversas condições patológicas como leucemias, mieloma múltiplo, linfoma de Burkitt e gastrite com corpúsculos de Russell, sendo raramente observadas em leucemias mieloides agudas. O presente estudo relata a presença de inclusões semelhantes aos corpúsculos de Russell em blastos no sangue periférico de uma paciente de 51 anos com leucemia mieloide aguda.

Changes in cell mechanisms result in the appearance of Russel bodies, which are basophilic intracytoplasmic inclusions. These inclusions occur due to cellular indigestion of proteins, and can be observed in several pathological conditions such as leukemias, multiple myeloma, Burkitt's lymphoma, and gastritis with Russell bodies, but rarely observed in acute myeloid leukemias. The present study reports the presence of inclusions similar to Russell bodies in peripheral blood blasts in a 51-year-old female patient with acute myeloid leukemia.

Bradicardia inducida por quimioterapia en pacientes oncológicos / Chemotherapy-induced bradycardia in oncology patients

Resumen Introducción: cada día se reportan efectos tóxicos de la quimioterapia en el corazón, entre ellos las arritmias; sin embargo, las publicaciones sobre bradicardia ocasionada por antineoplásicos son escasas. Objetivo: describir y analizar la presencia de bradicardia posquimioterapia en el paciente oncológico. Materiales y métodos: estudio no experimental, descriptivo, retrospectivo, en el que se incluyeron pacientes atendidos durante el año 2017 en un Servicio de Cardiología, a causa de bradicardia posquimioterapia. Resultados: se evaluaron 59 pacientes, 31 varones (52,5%) y 28 mujeres (47,5%), con una mediana de edad de 42 años. La mediana de la frecuencia cardiaca fue 46 latidos por minuto. La bradicardia fue más frecuente en leucemia mielocítica aguda (25,42%), seguida por leucemia linfoblástica aguda (20,34%). Fue asintomática en el 88,13% de los casos. Los fármacos quimioterápicos relacionados con bradicardia en leucemia mielocítica aguda fueron la citarabina en combinación con la daunorubicina, mientras que en leucemia linfoblástica aguda fueron la vincristina en combinación con la daunorubicina. Se presentó intervalo QTc largo en 12 casos (20,34%). El tiempo entre quimioterapia y el inicio de la bradicardia fue 24 a 48 horas en 35,6% y la recuperación de la frecuencia cardiaca fue entre 24 a 48 horas en el 61,02%. Conclusiones: la bradicardia sinusal como efecto adverso de la quimioterapia, es más frecuente en la leucemia mielocítica aguda, mientras que los medicamentos antineoplásicos relacionados con la bradicardia más comunes fueron la citarabina y la daunorubicina.

Abstract Introduction: There are daily reports of the toxic effects of chemotherapy on the heart, among them are the arrhythmias. However, there are very few publications on bradycardia caused by anti-neoplastic treatment. Objective: To describe and analyse the presence of post-chemotherapy bradycardia in the oncology patient. Materials and methods: A non-experimental, descriptive and retrospective study was conducted on patients seen during the year 2017 in a Cardiology Department due to post-chemotherapy bradycardia. Results: A total of 59 patients were evaluated, of whom 31 (52.5%) were males and 28 (47.5%) women, and with a median age of 42 years. The median heart rate was 46 beats per minute. The bradycardia was more common in acute myelocytic leukaemia (25.42%), followed by acute lymphoblastic leukaemia (20.34%). It was asymptomatic in 88.31% of cases. The chemotherapy drugs associated with bradycardia in acute myelocytic leukaemia were cytarabine in combination with daunorubicin, whilst in acute lymphoblastic leukaemia they were vincristine in combination with daunorubicin. A prolonged QTc interval was present in 12 (20.34%) of cases. The time between the chemotherapy and the onset of bradycardia was 24 to 48 hours in 35.6%, and the recovery of the heart rate was between 24 and 48 hours in 61.02%. Conclusions: Sinus bradycardia as an adverse effect of chemotherapy is more frequent in acute myelocytic leukaemia, whilst the most common anti-neoplastic drugs associated with bradycardia were cytarabine and daunorubicin.

Proteinosis alveolar secundaria: reporte de un caso / Proteinosis alveolar secundaria: case report

La proteinosis alveolar es un enfermedad caracterizada por el acúmulo anormal de surfactante en el espacio alveolar lo que conlleva a disrupción en el intercambio gaseoso. Su fisiopatogenia es variada y en los adultos la forma secundaria es la más frecuente. Presentamos el caso de una paciente con leucemia mieloide aguda en tratamiento compasivo con gemtuzumab ozogamicina, e infecciones respiratorias a repetición que se presenta con disnea progresiva y tos seca. Luego de descartar causa embólica y cardíaca, se realiza tomografía que evidencia opacidades en vidrio esmerilado de distribución difusa y engrosamiento de septos, por lo que ante la sospecha de infección se realiza lavado broncoalveolar que revela líquido blanquecino evidenciando en la citología inclusiones en macrógrafos PAS positivo. Con el diagnóstico de proteinosis alveolar secundaria a enfermedad de base, se reinició tratamiento quimioterápico. Presentó progresión de infiltrados y mayor requerimiento de oxígeno falleciendo pocos días después. (AU)

Characterization and Cytotoxic Evaluation of Silver and Gold Nanoparticles Produced with Aqueous Extract of Lavandula dentata L. in Relation to K-562 Cell Line

Abstract Metallic nanoparticles have great potential as a chemotherapeutic agent. The aim of this study was to develop and characterize silver and gold nanoparticles using a simple method, as well as evaluating the potential cytotoxic activity in relation to the K-562 cell line. For the synthesis, a solution containing the metallic ions was subjected to magnetic stirring with the aqueous extract of Lavandula dentata L. and a change of colour was observed. With the data obtained from the analyses we concluded that the nanoparticles were successfully obtained by a simple and green method using the aqueous extract of L. dentata. The obtained nanoparticles presented a reduced size, a low level of polydispersion, and a homogenous spherical shape. The nanoparticles presented intense and characteristic diffraction peaks, which could be correlated to the planes of the centred cubic structure of the silver and gold. The two formulations presented predominantly crystalline characteristics. The infrared analysis suggested that the amides and alcohols present in the samples may have been responsible for the reduction and limitation of the size and dispersion of the silver and gold nanoparticles. The cytotoxic assay showed that the nanoparticles demonstrated great potential to reduce the cell viability of the K-562 cell line, especially the gold nanoparticles.

Pre-analytical parameters associated with unsuccessful karyotyping in myeloid neoplasm: a study of 421 samples

Cytogenetics is essential in myeloid neoplasms (MN) and pre-analytical variables are important for karyotyping. We assessed the relationship between pre-analytical variables (time from collection to sample processing, material type, sample cellularity, and diagnosis) and failures of karyotyping. Bone marrow (BM, n=352) and peripheral blood (PB, n=69) samples were analyzed from acute myeloid leukemia (n=113), myelodysplastic syndromes (n=73), myelodysplastic syndromes/myeloproliferative neoplasms (n=17), myeloproliferative neoplasms (n=137), and other with conclusive diagnosis (n=6), and reactive disorders/no conclusive diagnosis (n=75). The rate of unsuccessful karyotyping was 18.5% and was associated with the use of PB and a low number of nucleated cells (≤7×103/µL) in the sample. High and low cellularity in BM and high and low cellularity in PB samples showed no metaphases in 3.9, 39.7, 41.9, and 84.6% of cases, respectively. Collecting a good BM sample is the key for the success of karyotyping in MN and avoids the use of expensive molecular techniques.

Molecular cytogenetic characterization of five patients with myeloid leukemia and t(12;22)(p13;q12) / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical and laboratory characteristics of 5 patients with myeloid leukemia and t(12;22)(p13;q12).@*METHODS@#Bone marrow cells were cultured for 24 h and analyzed by standard R-banding. Rearrangement of the MN1 gene was detected by fluorescence in situ hybridization (FISH) using dual color break-apart MN1 probes. MN1-ETV6 and ETV6-MN1 fusion genes were detected by reverse transcription polymerase chain reaction (RT-PCR). And the products were subjected to direct sequencing.@*RESULTS@#Among the 5 patients, 2 had AML-M0, 2 had AML-M4, and 1 had CMML at the initial diagnosis. t(12;22)(p13;q12) was the primary abnormality among all patients. Rearrangements of MN1 gene were detected by FISH in all patients. MN1-ETV6 and ETV6-MN1 fusion genes were detected respectively in 4 and 3 patients.@*CONCLUSION@#t(12;22)(p13;q12) is a rare but recurrent chromosomal abnormality in myeloid leukemia, and is related to poor prognosis. allo-SCT is valuable for patients with t(12;22)(p13;q12).

Clinical and pathological features of myeloid leukemia cutis

Abstract: Background: Myeloid leukemia cutis is the terminology used for cutaneous manifestations of myeloid leukemia. Objective: The purpose of this study was to study the clinical, histopathological and immunohistochemical features of myeloid leukemia cutis. Methods: This was a retrospective study of clinical and pathological features of 10 patients with myeloid leukemia cutis. Results: One patient developed skin lesions before the onset of leukemia, seven patients developed skin infiltration within 4-72 months after the onset of leukemia, and two patients developed skin lesions and systemic leukemia simultaneously. Of these patients, five presented with generalized papules or nodules, and five with localized masses. The biopsy of skin lesions showed a large number of tumor cells within the dermis and subcutaneous fat layer. Immunohistochemical analysis showed strong reactivity to myeloperoxidase (MPO), CD15, CD43 and CD45 (LCA) in most cases. NPM1 (nucleophosmin I) and FLT3-ITD (Fms-like tyrosine kinase 3-internal tandem duplication) mutations were identified in one case. Five patients with acute myelogenous leukemia and one patient with chronic myelomonocytic leukemia died within two months to one year after the onset of skin lesions. Study limitations: This was a retrospective and small sample study. Conclusions: In patients with myelogenous leukemia, skin infiltration usually occurs after, but occasionally before, the appearance of hemogram and myelogram abnormalities, and the presence of skin infiltration is often associated with a poor prognosis and short survival time. myeloid leukemia cutis often presents as generalized or localized nodules or masses with characteristic pathological and histochemical findings.

Situación actual de la leucemia mieloide crónica en Costa Rica / (Current situation of chronic myeloid leukemia in Costa Rica)

Resumen Justificación y objetivo: la leucemia mieloide crónica constituye un paradigma de reversión de neoplasia con un tratamiento específico basado en los inhibidores de tirosina quinasa. Aunque la situación epidemiológica ha sido estudiada en países primermundistas, los estudios en Latinoamérica son escasos. Con el fin de actualizar la situación real de la LMC en la región centroamericana, el estudio pretende describir la epidemiología de la leucemia mieloide crónica en Costa Rica. Métodos: se evaluaron 133 pacientes con la enfermedad, mediante monitoreo hematológico y molecular. Se analizó la respuesta de estos casos a tratamiento conforme a las siguientes variables: respuesta hematológica, respuesta molecular y supervivencia global, libre de evento, progresión, así como la prevalencia de mutaciones que confieren resistencia al tratamiento. Resultados: la respuesta hematológica completa fue del 97,7%, y la molecular mayor, a los 12 meses, fue del 43,4%. El seguimiento recomendado por la guía European LeukemiaNet se alcanzó solo en un 68,4% de los pacientes en el primer año, bajando al 57,7%, posteriormente. Un total de 92 pacientes alcanzó respuesta molecular mayor en algún momento; de ellos, el 87,0% conservó respuesta. La supervivencia libre de evento a 3 años fue del 65,7%, libre de progresión del 92,2% y global del 89,2%. La mutación más frecuente encontrada en el gen ABL fue la T315I. Conclusión: el tratamiento de la leucemia mieloide crónica en Costa Rica presenta una eficacia comparable a lo reportado en otros países, con una respuesta molecular mayor inferior a lo esperado, debido a dificultades de acceso al medicamento y monitoreo de la enfermedad.

Abstract Background and aim: Chronic myeloid leukemia is a paradigm of reversion of neoplasia with a specific treatment based on tyrosine kinase inhibitors. Although the epidemiological situation has been studied in first world countries, studies in Latin American countries are scarce. In order to update the real situation of the chronic myeloid leukemia in our Central American region, this study aims to describe the epidemiology of chronic myeloid leukemia in Costa Rica. Methods: 133 patients with the disease were evaluated through hematological and molecular monitoring. The response of these cases to treatment was analyzed by the following variables: haematological response, molecular response and overall survival, event-free, progression, as well as the prevalence of mutations that confer resistance to treatment. Results: The complete haematological response was 97.7% and the molecular response greater than 12 months was 43.4%. The follow-up recommended by the European LeukemiaNet guideline was reached in only 68.4% of the patients in the first year, decreasing to 57.7% later on. A total of 92 patients achieved a higher molecular response at some point, of which 87.0% retained a response. The 3-year event-free survival was 65.7%, progression free of 92.2% and overall of 89.2%. The most frequent mutation found in the ABL gene was T315I. Conclusion: The treatment of chronic myeloid leukemia in Costa Rica presents an efficacy comparable to that reported in other countries, with a lower molecular response than expected due to difficulties in accessing medication and monitoring the disease.

Bullous pyoderma gangrenosum as a predictor of hematological malignancies

Abstract: Pyoderma gangrenosum may precede, coexist or follow diverse systemic diseases. The bullous variety is usually associated with hematologic disorders. From 31 patients with pyoderma gangrenosum diagnosed in our hospital during 10 years, only 2 presented with the bullous type. One patient had previous diagnosis of chronic myeloid leukemia. Both had fast-progressive, painful lesions, and both showed an excellent response to systemic corticosteroids. In less than 3 months the lesions recurred simultaneously with the progression of chronic myeloid leukemia in one patient and with the initial diagnosis of acute myeloid leukemia in the other one. They died in less than four weeks. These findings emphasize the importance of its timely diagnosis. Cutaneous lesions could be the first predictor of an underlying disease.

Insulin Substrate Receptor (IRS) proteins in normal and malignant hematopoiesis

The insulin receptor substrate (IRS) proteins are a family of cytoplasmic proteins that integrate and coordinate the transmission of signals from the extracellular to the intracellular environment via transmembrane receptors, thus regulating cell growth, metabolism, survival and proliferation. The PI3K/AKT/mTOR and MAPK signaling pathways are the best-characterized downstream signaling pathways activated by IRS signaling (canonical pathways). However, novel signaling axes involving IRS proteins (noncanonical pathways) have recently been identified in solid tumor and hematologic neoplasm models. Insulin receptor substrate-1 (IRS1) and insulin receptor substrate-2 (IRS2) are the best-characterized IRS proteins in hematologic-related processes. IRS2 binds to important cellular receptors involved in normal hematopoiesis (EPOR, MPL and IGF1R). Moreover, the identification of IRS1/ABL1 and IRS2/JAK2V617F interactions and their functional consequences has opened a new frontier for investigating the roles of the IRS protein family in malignant hematopoiesis. Insulin receptor substrate-4 (IRS4) is absent in normal hematopoietic tissues but may be expressed under abnormal conditions. Moreover, insulin receptor substrate-5 (DOK4) and insulin receptor substrate-6 (DOK5) are linked to lymphocyte regulation. An improved understanding of the signaling pathways mediated by IRS proteins in hematopoiesis-related processes, along with the increased development of agonists and antagonists of these signaling axes, may generate new therapeutic approaches for hematological diseases. The scope of this review is to recapitulate and review the evidence for the functions of IRS proteins in normal and malignant hematopoiesis.

Cytotoxic and pro-apoptotic action of MjTX-I, a phospholipase A2 isolated from Bothrops moojeni snake venom, towards leukemic cells

A leucemia mieloide crônica (LMC) é uma neoplasia mieloproliferativa BCR-ABL1 + marcada por aumento da mieloproliferação e presença de células leucêmicas resistentes à apoptose. A terapia de primeira linha atual para a LMC é a administração de inibidores da tirosina quinase, mesilato de imatinibe, dasatinibe ou nilotinibe. Embora eficaz no tratamento da LMC, alguns pacientes se tornaram resistentes a essa terapia, levando à progressão da doença e à morte. Assim, a descoberta de novos compostos para melhorar a terapia da LMC ainda é um desafio. Aqui, os destinatários se MjTX-I, uma fosfolipase A 2 isolado a partir de Bothrops moojeni de veneno de cobra, afecta a viabilidade de Bcr-Abl de mesilato de imatinib-resistente + linhas celulares. Métodos: Examinamos o efeito citotóxico e pró-apoptótico de MjTX-I em células K562-S e K562-R Bcr-Abl + e na linha de células HEK-293 não tumorais e células mononucleares de sangue periférico, usando o 3- (4, Brometo de 5-dimetiltiazol-2-il) -2,5-difeniltetrazólio e os métodos de solução fluorescente hipotônica, associados à detecção de ativação de caspases 3, 8 e 9 e clivagem de poli (ADP-ribose) polimerase (PARP). Também analisamos o potencial MjTX-I para modular a expressão de genes relacionados à apoptose em células K562-S e K562-R. Resultados: O MjTX-I diminuiu a viabilidade das células K562-S e K562-R em 60 a 65%, sem afetar a viabilidade das células não tumorais, ou seja, exerceu citotoxicidade seletiva para as linhagens celulares Bcr-Abl + . Em linhas de células leucêmicas, a toxina induziu apoptose, caspases 3, 8 e 9 ativadas, PARP clivada, expressão negativa do gene anti-apoptótico BCL-2 e expressão aumentada do gene pró-apoptótico BAD. Conclusão: O efeito antitumoral de MjTX-I está associado ao seu potencial para induzir apoptose e citotoxicidade em linhagens celulares positivas para Bcr-Abl sensíveis e resistentes ao mesilato de imatinibe, indicando que MjTX-I é um candidato promissor a fármaco para atualizar a terapia de LMC.(AU)

Does formaldehyde have a causal association with nasopharyngeal cancer and leukaemia?

BACKGROUND: The South Korean criteria for occupational diseases were amended in July 2013. These criteria included formaldehyde as a newly defined occupational carcinogen, based on cases of “leukemia or nasopharyngeal cancer caused by formaldehyde exposure”. This inclusion was based on the Internal Agency for Research on Cancer classification, which classified formaldehyde as definite human carcinogen for nasopharyngeal cancer in 2004 and leukemia in 2012. METHODS: We reviewed reports regarding the causal relationship between occupational exposure to formaldehyde in Korea and the development of these cancers, in order to determine whether these cases were work-related. RESULTS: Previous reports regarding excess mortality from nasopharyngeal cancer caused by formaldehyde exposure seemed to be influenced by excess mortality from a single plant. The recent meta-risk for nasopharyngeal cancer was significantly increased in case-control studies, but was null for cohort studies (excluding unexplained clusters of nasopharyngeal cancers). A recent analysis of the largest industrial cohort revealed elevated risks of both leukemia and Hodgkin lymphoma at the peak formaldehyde exposure, and both cancers exhibited significant dose-response relationships. A nested case-control study of embalmers revealed that mortality from myeloid leukemia increased significantly with increasing numbers of embalms and with increasing formaldehyde exposure. The recent meta-risks for all leukemia and myeloid leukemia increased significantly. In South Korea, a few cases were considered occupational cancers as a result of mixed exposures to various chemicals (e.g., benzene), although no cases were compensated for formaldehyde exposure. The peak formaldehyde exposure levels in Korea were 2.70–14.8 ppm in a small number of specialized studies, which considered anatomy students, endoscopy employees who handled biopsy specimens, and manufacturing workers who were exposed to high temperatures. CONCLUSION: Additional evidence is needed to confirm the relationship between formaldehyde exposure and nasopharyngeal cancer. All lymphohematopoietic malignancies, including leukemia, should be considered in cases with occupational formaldehyde exposure.