Exploring redox vulnerabilities in JAK2V617F-positive cellular models

ABSTRACT Background: In Philadelphia chromosome-negative myeloproliferative neoplasm (MPN) models, reactive oxygen species (ROS) are elevated and have been implicated in genomic instability, JAK2/STAT signaling amplification, and disease progression. Although the potential effects of ROS on the MPN phenotype, the effects of ruxolitinib treatment on ROS regulation have been poorly explored. Herein, we have reported the impact of ruxolitinib on redox signaling transcriptional network, and the effects of diphenyleneiodonium (DPI), a pan NOX inhibitor, in JAK2V617F-driven cellular models. Method: Redox signaling-related genes were investigated in SET2 cells upon ruxolitinib treatment by RNA-seq (GEO accession GSE69827). SET2 and HEL cells, which represent JAK2V617F-positive MPN cellular models with distinct sensitivity to apoptosis induced by ruxolitinib, were used. Cell viability was evaluated by MTT, apoptosis by annexin V/PI and flow cytometry, and cell signaling by quantitative PCR and Western blot. Main results: Ruxolitinib impacted on a network composed of redox signaling-related genes, and DUOX1 and DUOX2 were identified as potential modulators of ruxolitinib response. In SET2 and HEL cells, DPI reduced cell viability and, at low doses, it significantly potentiated ruxolitinib-induced apoptosis. In the molecular scenario, DPI inhibited STAT3, STAT5 and S6 ribosomal protein phosphorylation and induced PARP1 cleavage in JAK2V617F-positive cells. DPI combined with ruxolitinib increased PARP1 cleavage in SET2 cells and potentiated ruxolitinib-reduced STAT3, STAT5 and S6 ribosomal protein in HEL cells. Conclusion: Our study reveals a potential adaptation mechanism for resistance against ruxolitinib by transcriptionally reprogramming redox signaling in JAK2V617F cells and exposes redox vulnerabilities with therapeutic value in MPN cellular models.

Clinical and molecular profile of a Brazilian cohort of patients with classical BCR-ABL1-negative myeloproliferative neoplasms

ABSTRACT Background: The classical BCR-ABL1-negative myeloproliferative neoplasms (MPNs) are Polycythemia Vera (PV), Essential Thrombocythemia (ET) and Primary Myelofibrosis (PMF). In developing countries, there are few reports that truly reveal the clinical setting of these patients. Therefore, we aimed to characterize a single center MPN population with a special focus on the correct diagnosis based on the recent review of the WHO criteria for the diagnosis of myeloid neoplasms. Methods: This retrospective study analyzed data from medical records of patients with classical BCR-ABL1-negative MPNs diagnosed from January 1997 to October 2017 and followed at the University Hospital of Ribeirão Preto Medical School. Results: A total of 162 patients were assessed, 61 with PV, 50 with ET, and 51 with PMF. The mutational status analysis revealed that 113 (69.3%) harbored the JAK2V617F mutation, 23 (14.1%), the CALR mutation, and 12 (7.4%) had a triple-negative status. None of the patients were found to have mutations on the thrombopoietin receptor gene (MPL), including some ET and PMF patients who were not tested. Among the PV patients, 57 (93.5%) were positive for the JAK2V617F mutation, one (1.6%) presented an in-frame deletion JAK2 exon 12 mutation and one (1.6%) presented a missense JAK2 exon 9 mutation, not previously described. The overall survival was lower in the triple-negative patients with PMF, when compared to the JAK2V617F or CALR-mutated (p= 0.002). Conclusion: The frequency of somatic mutations and survival in our cohort, stratified according to the respective disease, was consistent with the literature data, despite some limitations. Further prospective epidemiological studies of MPN cohorts are encouraged in developing countries.

O papel do profissional biólogo na residência multiprofissional em saúde coletiva: um relato de experiência / The role of the biologist professional in the multiprofessional residence in collective health: a report of experience

Os programas de residência no Brasil têm evoluído ao longo do tempo. Com o advento das residências multiprofissionais, essa pós-graduação deixou de ser exclusiva dos profissionais médicos, gerando oportunidade para outras categorias profissionais e possibilitando a oferta de um olhar multidisciplinar para os usuários do Sistema Único de Saúde. O Programa de Residência Multiprofissional em Saúde Coletiva (PRMSC) da Universidade Regional do Cariri (URCA) inclui em seu quadro de profissionais o biólogo, que encerrará a formação apto a participar e desenvolver ações no campo da saúde ambiental e nos diferentes cenários da rede de atenção em saúde em todos os seus níveis, além de atuar junto a comunidade nos processos de enfrentamento do mosquito Aedes aegypti. O presente trabalho é um relato de experiência que visa refletir sobre a inserção do biólogo dentro do PRMSC-URCA e descrever os desafios enfrentados por esse profissional na sua inserção dentro dos serviços de saúde. Os dois grandes entraves da inclusão do bíologo na área da saúde são a ausência de preceptoria e o fato de não realizarem atendimento clínico. Como alternativas de intrevenção estão as ações educativas, a implementação de hortas comunitárias e os programas de biossegurança para as unidades. As especificidades da formação do profissional biólogo são um desafio a ser vencido e que caminha de mãos dadas com a responsabilidade de abrir e assegurar um novo campo de atuação para a categoria. Dessa forma, é necessário que haja uma dedicação e valorização desse profissional, objetivando sua fixação no programa e seu crescimento junto a saúde

Residence programs in Brazil have evolved throughout the time. With the advent of multi-professional residences, this postgraduate program is no longer exclusive to medical professionals, creating opportunities to other professional categories and enabling the offer of a multidisciplinary view for the users of the Brazilian Unified National Health System. The Multi- professional Residency Program in Collective Health (PRMSC) of the Regional University of Cariri (URCA) includes in its professional staff biologists, who will at the end of the program be able to participate and develop actions in the field of environmental health and in the different scenarios of the health care network, at all levels, besides working with the community in the processes of coping the Aedes aegypti mosquito. The present work is an experience report that aims to reflect over the insertion of the biologist within the PRMSC-URCA and describe the challenges faced by this professional in their insertion within the health services. The two major obstacles to the inclusion of the biologist in the health area are the absence of preceptorship and the fact that they do not perform clinical care. As alternatives for intervention are the educational actions and the implementation of community gardens and biosafety programs for the units. The specifics of the educational background of the professional biologist are a challenge to be overcome and that goes hands tied with the responsibility to open and ensure a new field of action for the category. In this way, it is necessary that there is a dedication and valorization of this professional, aiming its fixation in the program and its growth together with health.

Los programas de residencia en Brasil han evolucionado a lo largo del tiempo. Con el advenimiento de las residencias multiprofesionales, posgrados como tal dejan de ser exclusivo de los profesionales médicos, generando oportunidad para otras categorías profesionales y posibilitando la oferta de uma perspectiva multidisciplinar para los usuarios del Sistema Único de Salud. El Programa de Residencia Multiprofesional en Salud Colectiva (PRASC) de la Universidad Regional del Cariri (URCA) incluye en su cuadro de profesional el biólogo, que encerrará los estudios apto para participar y desarrollar acciones en el campo de la salud ambiental y en los diferentes escenarios de la red de atención en salud en todos sus niveles, además de actuar junto de la comunidad en los procesos de enfrentamiento del mosquito Aedes aegypti. El presente trabajo es un relato de experiencia que pretende reflexionar sobre la inserción del biólogo dentro del PRMSC-URCA y describir los desafíos enfrentados por ese profesional en su inserción dentro de los servicios de salud. Los dos grandes obstáculos a la inclusión del biólogo en el área de la salud son la ausencia de precepción y la non realización de trabajos de atención al cliente. Como alternativas de intervención están las acciones educativas, la implementación de huertos comunitarios y los programas de bioseguridad para las unidades. Las especificidades de la formación del profesional biólogo son un desafío a ser vencido y que camina de la mano de la responsabilidad de abrir y asegurar un nuevo campo de actuación para la categoría. De esa forma, es necesario que haya una dedicación y valorización de ese profesional, objetivando su fijación en el programa y su crecimiento junto a la salud.

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.

TET2 is upregulated during erythroid differentiation of CD34+ cells from healthy donors and myelodysplastic syndrome patients

Background: Tet methylcytosine dioxygenase 2 (TET2) is frequently mutated and/or downregulated in myeloid neoplasm, including myelodysplastic syndromes. Despite the extensive studies, the specific contribution of TET2 in disease phenotype of myeloid neoplasms is not fully elucidated. Recent findings have grown attention on the role of TET2 in normal and malignant erythropoiesis. Methods: In the present study, we investigated TET2 mRNA levels by quantitative PCR during erythropoietin-induced erythroid differentiation CD34+ cells from healthy donor and myelodysplastic syndrome patients. Statistical analyses were performed using the ANOVA and Bonferroni post hoc test and a p-value <0.05 was considered statically significant. Results: TET2 expression is upregulated during erythroid differentiation of CD34+ cells from healthy donor and myelodysplastic syndrome patients. Conclusions: Our findings corroborate that TET2 is involved in the erythrocyte differentiation (AU)

IL32 expression in peripheral blood CD3+ cells from myelodysplastic syndromes patients

Background: Myelodysplastic syndromes (MDS) are a heterogeneous group of disorders characterized by ineffective hematopoiesis and risk of leukemia transformation. There is evidence to suggest the participation of immune system deregulation in MDS pathogenesis. Interleukin-32 (IL-32) is a newly described multifunctional cytokine reported as an important mediator in autoimmune and inflammatory disorders. In the present study, we reported the expression of IL32 and IL32 transcript variants (α, ß, γ and δ) in peripheral blood CD3+ cells from healthy controls and MDS patients. Methods: CD3+ cells were isolated by immunomagnetic cell sorting from thirty-nine untreated MDS patients and twenty-nine healthy donors. Gene expression was evaluated by quantitative PCR. For statistical analysis, Mann­Whitney test, Kruskal-Wallis test with Dunns post test and Log-rank (Mantel-Cox) were used, as appropriate. A p value <0.05 was considered statistically significant. Results: IL32 expression and IL32 transcript variants IL32α, IL32ß, IL32γ, and IL32δ, were similar in peripheral blood CD3+ cells from healthy donors and MDS patients. Increased IL-32α expression was an independent predictor for MDS disease progression by univariate and multivariate analysis. Conclusions: We observed that IL32 expression is not differently expressed in CD3+ cells from MDS patients; nevertheless IL32α has a potential role in disease progression (AU)

SIVA, a target of p53, is downregulated in myelodysplastic syndromes

Background: SIVA is a transcriptional target of p53 that plays a potential role in the development and progression of cancer. In this study, we analyzed SIVA1 and SIVA2 expression, and its association with clinical features and TP53 and MDM2 expression in bone marrow cells from healthy donors and myelodysplastic syndrome (MDS) patients. Methods: Fifty-five untreated patients with MDS and 22 healthy donors were included. Gene expression was evaluated by quantitative PCR. For statistical analysis, Mann­Whitney test, Spearman correlation analysis and Log-rank (Mantel-Cox) were used, as appropriate. A p value <0.05 was considered statistically significant. Results: SIVA1 and SIVA2 transcripts were significantly decreased in bone marrow samples from MDS patients compared to healthy donors, and positively correlated with MDM2 and TP53 expression in MDS patients (all p < 0.05). MDM2 expression was also downregulated in bone marrow samples from MDS patients compared to healthy donors (p < 0.05). However, SIVA1, SIVA2, MDM2 and TP53 expressions did not impact on MDS outcomes. Conclusions: SIVA1 and SIVA2 transcripts are downregulated in bone marrow samples from MDS patients (AU)

PTK2 and PTPN11 expression in myelodysplastic syndromes

OBJECTIVE: The aim of this study was to evaluate the expression of protein tyrosine kinase 2 and protein tyrosine phosphatase non-receptor type 11, which respectively encode focal adhesion kinase protein and src homology 2 domain-containing protein-tyrosine phosphatase 2, in hematopoietic cells from patients with myelodysplastic syndromes. METHODS: Protein tyrosine kinase 2 and tyrosine phosphatase non-receptor type 11 expressions were analyzed by quantitative polymerase chain reaction in bone marrow cells from patients with myelodysplastic syndromes and healthy donors. RESULTS: Protein tyrosine kinase 2 and tyrosine phosphatase non-receptor type 11 expressions did not significantly differ between normal cells and myelodysplastic cells. CONCLUSIONS: Our data suggest that despite the relevance of focal adhesion kinase and src homology 2 domain-containing protein-tyrosine phosphatase 2 in hematopoietic disorders, their mRNA expression do not significantly differ between total bone marrow cells from patients with myelodysplastic syndromes and healthy donors. .

Screening for hotspot mutations in PI3K, JAK2, FLT3 and NPM1 in patients with myelodysplastic syndromes

INTRODUCTION: Myelodysplastic syndromes encompass a heterogeneous group of clonal hematopoietic stem cell disorders characterized by ineffective hematopoiesis, refractory cytopenia and a tendency to progress toward acute myeloid leukemia. The accumulation of genetic alterations is closely associated with the progression of myelodysplastic syndromes toward acute myeloid leukemia. OBJECTIVE: To investigate the presence of mutations in the points most frequent for mutations (hotspot mutations) in phosphatidylinositol-3-kinase (PI3K), Janus kinase 2 (JAK2), FMS-like tyrosine kinase 3 (FLT3) and nucleophosmin (NPM1), which are involved in leukemia and other cancers, in a population of Brazilian MDS patients. METHODS: Fifty-one myelodysplastic syndromes patients were included in the study. According to French-American-British classification, the patients were distributed as follows: 31 with refractory anemia, 8 with refractory anemia with ringed sideroblasts, 7 with refractory anemia with excess blasts, 3 with refractory anemia with excess blasts in transformation and 2 with chronic myelomonocytic leukemia. Bone marrow samples were obtained and screened for the presence of hotspot mutations using analysis based on amplification with the polymerase chain reaction, sequencing, fragment size polymorphisms or restriction enzyme digestion. All patients were screened for mutations at the time of diagnosis, and 5 patients were also screened at the time of disease progression. RESULTS: These results show that hotspot mutations in the PI3K, JAK2, FLT3 and NPM1 genes are not common in MDS patients; nevertheless, JAK2 mutations may be present in myelodysplasia during disease progression. CONCLUSIONS: These results show that hotspot mutations in the PI3K, JAK2, FLT3 and NPM1 genes are not common in MDS patients; nevertheless, JAK2 mutations may be present in myelodysplasia during disease progression.