CD19 CAR T cells for B cell malignancies: a systematic review and meta-analysis focused on clinical impacts of CAR structural domains, manufacturing conditions, cellular product, doses, patient's age, and tumor types.

CD19-targeted chimeric antigen receptors (CAR) T cells are one of the most remarkable cellular therapies for managing B cell malignancies. However, long-term disease-free survival is still a challenge to overcome. Here, we evaluated the influence of different hinge, transmembrane (TM), and costimulatory CAR domains, as well as manufacturing conditions, cellular product type, doses, patient's age, and tumor types on the clinical outcomes of patients with B cell cancers treated with CD19 CAR T cells. The primary outcome was defined as the best complete response (BCR), and the secondary outcomes were the best objective response (BOR) and 12-month overall survival (OS). The covariates considered were the type of hinge, TM, and costimulatory domains in the CAR, CAR T cell manufacturing conditions, cell population transduced with the CAR, the number of CAR T cell infusions, amount of CAR T cells injected/Kg, CD19 CAR type (name), tumor type, and age. Fifty-six studies (3493 patients) were included in the systematic review and 46 (3421 patients) in the meta-analysis. The overall BCR rate was 56%, with 60% OS and 75% BOR. Younger patients displayed remarkably higher BCR prevalence without differences in OS. The presence of CD28 in the CAR's hinge, TM, and costimulatory domains improved all outcomes evaluated. Doses from one to 4.9 million cells/kg resulted in better clinical outcomes. Our data also suggest that regardless of whether patients have had high objective responses, they might have survival benefits from CD19 CAR T therapy. This meta-analysis is a critical hypothesis-generating instrument, capturing effects in the CD19 CAR T cells literature lacking randomized clinical trials and large observational studies.

Disruption of the ZFP574-THAP12 complex suppresses B cell malignancies in mice.

Despite the availability of life-extending treatments for B cell leukemias and lymphomas, many of these cancers remain incurable. Thus, the development of new molecular targets and therapeutics is needed to expand treatment options. To identify new molecular targets, we used a forward genetic screen in mice to identify genes required for development or survival of lymphocytes. Here, we describe Zfp574, an essential gene encoding a zinc finger protein necessary for normal and malignant lymphocyte survival. We show that ZFP574 interacts with zinc finger protein THAP12 and promotes the G1-to-S-phase transition during cell cycle progression. Mutation of ZFP574 impairs nuclear localization of the ZFP574-THAP12 complex. ZFP574 or THAP12 deficiency results in cell cycle arrest and impaired lymphoproliferation. Germline mutation, acute gene deletion, or targeted degradation of ZFP574 suppressed Myc-driven B cell leukemia in mice, but normal B cells were largely spared, permitting long-term survival, whereas complete lethality was observed in control animals. Our findings support the identification of drugs targeting ZFP574-THAP12 as a unique strategy to treat B cell malignancies.

Off-the-shelf CAR-T cell therapies for relapsed or refractory B-cell malignancies: latest update from ASH 2023 annual meeting.

Currently, many off-the-shelf chimeric antigen receptor (CAR)-T cell products are under investigation for the treatment of relapsed or refractory (R/R) B-cell neoplasms. Compared with autologous CAR-T cell therapy, off-the-shelf universal CAR-T cell therapies have many potential benefits, such as immediate accessibility for patients, stable quality due to industrialized manufacturing and additional infusions of CAR-T cells with different targets. However, critical challenges, including graft-versus-host disease and CAR-T cell elimination by the host immune system, still require extensive research. The most common technological approaches involve modifying healthy donor T cells via gene editing technology and altering different types of T cells. This article summarizes some of the latest data from preclinical and clinical studies of off-the-shelf CAR-T cell therapies in the treatment of R/R B-cell malignancies from the 2023 ASH Annual Meeting (ASH 2023).

Targeting autophagy overcomes cancer-intrinsic resistance to CAR-T immunotherapy in B-cell malignancies.

BACKGROUND: Chimeric antigen receptor T (CAR-T) therapy has substantially revolutionized the clinical outcomes of patients with hematologic malignancies, but the cancer-intrinsic mechanisms underlying resistance to CAR-T cells remain yet to be fully understood. This study aims to explore the molecular determinants of cancer cell sensitivity to CAR-T cell-mediated killing and to provide a better understanding of the underlying mechanisms and potential modulation to improve clinical efficacy. METHODS: The human whole-genome CRISPR/Cas9-based knockout screening was conducted to identify key genes that enable cancer cells to evade CD19 CAR-T-cell-mediated killing. The in vitro cytotoxicity assays and evaluation of tumor tissue and bone marrow specimens were further conducted to confirm the role of the key genes in cancer cell susceptibility to CAR-T cells. In addition, the specific mechanisms influencing CAR-T cell-mediated cancer clearance were elucidated in mouse and cellular models. RESULTS: The CRISPR/Cas9-based knockout screening showed that the enrichment of autophagy-related genes (ATG3, BECN1, and RB1CC1) provided protection of cancer cells from CD19 CAR-T cell-mediated cytotoxicity. These findings were further validated by in vitro cytotoxicity assays in cells with genetic and pharmacological inhibition of autophagy. Notably, higher expression of the three autophagy-related proteins in tumor samples was correlated with poorer responsiveness and worse survival in patients with relapsed/refractory B-cell lymphoma after CD19 CAR-T therapy. Bulk RNA sequencing analysis of bone marrow samples from B-cell leukemia patients also suggested the clinical relevance of autophagy to the therapeutic response and relapse after CD19 CAR-T cell therapy. Pharmacological inhibition of autophagy and knockout of RB1CC1 could dramatically sensitize tumor cells to CD19 CAR-T cell-mediated killing in mouse models of both B-cell leukemia and lymphoma. Moreover, our study revealed that cancer-intrinsic autophagy mediates evasion of CAR-T cells via the TNF-α-TNFR1 axis-mediated apoptosis and STAT1/IRF1-induced chemokine signaling activation. CONCLUSIONS: These findings confirm that autophagy signaling in B-cell malignancies is essential for the effective cytotoxic function of CAR-T cells and thereby pave the way for the development of autophagy-targeting strategies to improve the clinical efficacy of CAR-T cell immunotherapy.

IKZF3/Aiolos H195Y mutation identified in a mouse model of B cell leukemia results in altered DNA binding and altered STAT5-dependent gene expression.

Precursor B cell acute lymphoblastic leukemia (Pre-B-ALL) arises from developing B cells and frequently involves mutations in genes encoding transcription factors. In this study, we investigated the function of mutations in the transcription factor IKZF3 (Aiolos), R137* and H195Y, discovered in a mouse model of pre-B-ALL. R137* IKZF3 mutation resulted in a truncated protein, while electrophoretic mobility shift assay showed that H195Y IKZF3 mutation resulted in a protein with altered DNA binding. 38B9 pre-B cell lines were generated expressing WT and H195Y IKZF3 proteins. Anti-IKZF3 ChIP-seq showed that H195Y IKZF3 interacted with a larger number of sites that were different than WT IKZF3. Treatment with interleukin-7 induced changes in gene expression in 38B9 cells expressing WT IKZF3, but did not induce any changes in gene expression in cells expressing H195Y IKZF3. Anti-STAT5 ChIP-seq showed that expression of H195Y IKZF3 resulted in redistribution of STAT5 binding sites in the genome. H195Y IKZF3 binding sites overlapped with a subset of STAT5 binding sites, including in the promoter of the Cish gene. These findings suggest that H195Y mutation of IKZF3 results in altered DNA binding specificity and altered binding of STAT5 to target genes.

Transcription factor 12-mediated self-feedback regulatory mechanism is required in DUX4 fusion leukaemia.

BACKGROUND: IGH::DUX4 is frequently observed in 4% B-cell acute lymphoblastic leukaemia patients. Regarding the IGH::DUX4-driven transactivation and alternative splicing, which are the main reasons behind this acute leukaemia outbreak, it remains unclear how transcriptional cofactors contribute to this oncogenic process. Further investigation is required to elucidate their specific role in leukaemogenesis. METHODS: In order to investigate the cofactors of IGH::DUX4, integrated mining of Chromatin immunoprecipitation (ChIP)-sequencing and RNA-sequencing of leukaemia cells and patient samples were conducted. Furthermore, to elucidate the synergistic interaction between transcription factor 12 (TCF12) and IGH::DUX4, knockdown and knockout experiment, mammalian two-hybridisation assay, co-immunoprecipitation and in situ proximity ligation assays were carried out. Additionally, to further investigate the direct interaction between TCF12 and IGH::DUX4, AI-based structural simulations were utilised. Finally, to validate the synergistic role of TCF12 in promoting IGH::DUX4 leukaemia, cell proliferation, apoptosis and drug sensitivity experiments were performed. RESULTS: In this study, we observed that the IGH::DUX4 target gene TCF12 might be an important cofactor/helper for this oncogenic driver. The co-expression of IGH::DUX4 and TCF12 resulted in enhanced DUX4-driven transactivation. Supportively, knockdown and knockout of TCF12 significantly reduced expression of IGH::DUX4-driven target genes in leukaemia REH (a precursor B-cell leukaemia cell line) and NALM-6 cells (a precursor B-cell leukaemia cell line). Consistently, in TCF12 knockout cells, the expression of structure-based TCF12 mutant, but not wild-type TCF12, failed to restore the TCF12-IGH::DUX4 crosstalk and the synergistic transactivation. More importantly, the breakdown in TCF12-IGH::DUX4 cooperation impaired IGH::DUX4-driven leukaemia cell survival, caused sensitivity to the chemotherapy. CONCLUSIONS: Altogether, these results helped to define a previously unrecognised TCF12-mediated positive self-feedback regulatory mechanism in IGH::DUX4 leukaemia, which holds the potential to function as a pivotal drug target for the management of this particular form of leukaemia. HIGHLIGHTS: Transcription factor 12 (TCF12) is a new novel cofactor in IGH::DUX4 transcriptional complexes/machinery. TCF12 mediates a positive self-feedback regulatory mechanism in IGH::DUX4-driven oncogenic transaction. IGH::DUX4-TCF12 structure/cooperation might represent a potent target/direction in future drug design against B-cell acute lymphoblastic leukaemia.

B-lymphoblastic leukemia with transient spontaneous remission in the setting of severe group A streptococcus infection.

Spontaneous remission of B-lymphoblastic leukemia (B-ALL) in the setting of viral and bacterial infections has been reported. Here, we present a case of B-ALL that showed a complete remission in the setting of group A streptococcal bacteremia. The patient was an 11-year-old boy who presented with a sore throat, right ear pain, and rhinorrhea. Prior to the diagnosis of B-ALL, he was diagnosed with streptococcal pharyngitis and received a single dose of dexamethasone and azithromycin. One day later, he was found to be pancytopenic and an immunophenotypically abnormal B-lymphoblastic population was detected comprising 0.6% and 16.8% of the peripheral blood and bone marrow cells, respectively. Though a diagnosis of B-ALL was highly suspected, blast percentage was <20% and the bone marrow showed relatively unremarkable trilineage hematopoiesis. On close monitoring, the suspected neoplastic population became undetectable by day 17 and the patient's complete blood count (CBC) completely normalized by day 46. On day 82, a peripheral blood smear demonstrated circulating blasts. Flow cytometry of a bone marrow aspirate revealed B-lymphoblastic leukemia accounting for 94% nucleated cells, consistent with the diagnosis of B-lymphoblastic leukemia. This case is of interest as less than 20 examples of spontaneous remission of B-ALL have been reported in the literature. As the case reported here relapsed and previously reported spontaneously remitting cases have uniformly relapsed, cases of B-ALL with spontaneous remission should be followed very closely for recurrence.

A retrospective comparative study of haplotype hematopoietic stem cell transplantation and human leukocyte antigen-matched sibling donor hematopoietic stem cell transplantation in the treatment of acute B-lymphocyte leukemia / 中华血液学杂志

Objective: To investigate whether haplotype hematopoietic stem cell transplantation (haplo-HSCT) is effective in the treatment of pre transplant minimal residual disease (Pre-MRD) positive acute B lymphoblastic leukemia (B-ALL) compared with HLA- matched sibling donor transplantation (MSDT) . Methods: A total of 998 patients with B-ALL in complete remission pre-HSCT who either received haplo-HSCT (n=788) or underwent MSDT (n=210) were retrospectively analyzed. The pre-transplantation leukemia burden was evaluated according to Pre-MRD determinedusing multiparameter flow cytometry (MFC) . Results: Of these patients, 997 (99.9% ) achieved sustained, full donor chimerism. The 100-day cumulative incidences of neutrophil engraftment, platelet engraftment, and grades Ⅱ-Ⅳ acute graft-versus-host disease (GVHD) were 99.9% (997/998) , 95.3% (951/998) , and 26.6% (95% CI 23.8% -29.4% ) , respectively. The 3-year cumulative incidence of total chronic GVHD was 49.1% (95% CI 45.7% -52.4% ) . The 3-year cumulative incidence of relapse (CIR) and non-relapse mortality (NRM) of the 998 cases were 17.3% (95% CI 15.0% -19.7% ) and 13.8% (95% CI 11.6% -16.0% ) , respectively. The 3-year probabilities of leukemia-free survival (LFS) and overall survival (OS) were 69.1% (95% CI 66.1% -72.1% ) and 73.0% (95% CI 70.2% -75.8% ) , respectively. In the total patient group, cases with positive Pre-MRD (n=282) experienced significantly higher CIR than that of subjects with negative Pre-MRD [n=716, 31.6% (95% CI 25.8% -37.5% ) vs 14.3% (95% CI 11.4% -17.2% ) , P<0.001]. For patients in the positive Pre-MRD subgroup, cases treated with haplo-HSCT (n=219) had a lower 3-year CIR than that of cases who underwent MSDT [n=63, 27.2% (95% CI 21.0% -33.4% ) vs 47.0% (95% CI 33.8% -60.2% ) , P=0.002]. The total 998 cases were classified as five subgroups, including cases with negative Pre-MRD group (n=716) , cases with Pre-MRD<0.01% group (n=46) , cases with Pre-MRD 0.01% -<0.1% group (n=117) , cases with Pre-MRD 0.1% -<1% group (n=87) , and cases with Pre-MRD≥1% group (n=32) . For subjects in the Pre-MRD<0.01% group, haplo-HSCT (n=40) had a lower CIR than that of MSDT [n=6, 10.0% (95% CI 0.4% -19.6% ) vs 32.3% (95% CI 0% -69.9% ) , P=0.017]. For patients in the Pre-MRD 0.01% -<0.1% group, haplo-HSCT (n=81) also had a lower 3-year CIR than that of MSDT [n=36, 20.4% (95% CI 10.4% -30.4% ) vs 47.0% (95% CI 29.2% -64.8% ) , P=0.004]. In the other three subgroups, the 3-year CIR was comparable between patients who underwent haplo-HSCT and those received MSDT. A subgroup analysis of patients with Pre-MRD<0.1% (n=163) was performed, the results showed that cases received haplo-HSCT (n=121) experienced lower 3-year CIR [16.0% (95% CI 9.4% -22.7% ) vs 40.5% (95% CI 25.2% -55.8% ) , P<0.001], better 3-year LFS [78.2% (95% CI 70.6% -85.8% ) vs 47.6% (95% CI 32.2% -63.0% ) , P<0.001] and OS [80.5% (95% CI 73.1% -87.9% ) vs 54.6% (95% CI 39.2% -70.0% ) , P<0.001] than those of MSDT (n=42) , but comparable in 3-year NRM [5.8% (95% CI 1.6% -10.0% ) vs 11.9% (95% CI 2.0% -21.8% ) , P=0.188]. Multivariate analysis showed that haplo-HSCT was associated with lower CIR (HR=0.248, 95% CI 0.131-0.472, P<0.001) , and superior LFS (HR=0.275, 95% CI 0.157-0.483, P<0.001) and OS (HR=0.286, 95% CI 0.159-0.513, P<0.001) . Conclusion: Haplo HSCT has a survival advantage over MSDT in the treatment of B-ALL patients with pre MRD<0.1% .

Bioinformatics Analysis and Verification of Acute B-Lymphocytic Leukemia in Children with Isolated Bone Marrow Relapse / 中国实验血液学杂志

OBJECTIVE@#To analyze the hub genes affecting the solely bone marrow relapse of childish acute B-cell lymphoblastic leukemia (B-ALL).@*METHODS@#The high-throughput RNA sequencing data were downloaded from TCGA database, the differentially expressed genes were screened by DESeq2 package of R, and the differentially expressed genes were grouped by GO function enrichment analysis and KEGG pathway enrichment analysis. Further, the data of STRING database and Cytoscape software were used to construct protein interaction network, screen hub genes and highly interaction protein sub network, perform GO and KEGG analysis of the hub genes and protein sub network respectively. JASPAR database was used to screen the upstream transcription factor of the hub gene promoter. Survival analysis based on the expression of hub genes was performed with clinical information attached to TCGA database. The bone marrow samples and clinical data of the patients were collected, the analysis results of hub genes were verified through clinical samples.@*RESULTS@#847 differentially expressed genes were collected, including 813 up-regulated genes, 34 down-regulated genes, 11 hub genes were screened out. The results of survival analysis showed that RPS5、RPS15、RPL23、RPL35、RPS8、RPS27A、RPS3、RPL9、RPS21、RPS7 and RPL38 showed significant effect on the survival of the children, and ZNF460 might be involved in their regulation. The high expressions of RPS3, RPS15, RPS8, RPS27A, and RPS21 had been verified in clinical samples of solely bone marrow relapsed patients.@*CONCLUSION@#RPS3, RPS15, RPS8, RPS27A, RPS21 can be used as biomarkers to indicate the malignant event of solely bone marrow relapse, which may be regulated by ZNF460.

Effect of MiR-142-3p Targeting HOXA5 on Proliferation, Cycle Arrest and Apoptosis of Acute B Lymphocytic Leukemia Cells / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect and molecular mechanism of miR-142-3p to the proliferation, cycle and apoptosis of acute B lymphocytic leukemia (B-ALL) cells by regulating the homeobox gene 5 (HOXA5) expression.@*METHODS@#Real-time fluorescence quantitative PCR was used to detect the expression levels of miR-142-3p and HOXA5 in human B-ALL cell Nalm6 cell line and human B lymphoblast Hmy2-cir cells. Nalm6 was transfected by using liposome transfection technology, miR-142-3p mimic, pcDNA-HOXA5 overexpression plasmid, miR-142-3p mimic+pcDNA-HOXA5 overexpression plasmid, and control. The binding site of HOXA5 and miR-142-3p was predicted according to microRNA.org, and the targeting relationship between miR-142-3p and HOXA5 gene was detected by double luciferase reporter gene experiment. The effect of miR-142-3p to the proliferation of Nalm6 cells was detected using the Cell Counting Box-8 (CCK-8) method and cell clone formation experiments. Flow cytometry was used to detect the effects of miR-142-3p to cell cycle distribution and apoptosis of Nalm6 cells. The expression levels of cell cycle-related proteins, including G@*RESULTS@#Compared with Hmy2-cir cells, miR-142-3p showed low expression in Nalm6 cells and HOXA5 showed high expression (P<0.05). MiR-142-3p and HOXA5 3'-UTR showed complementary binding regions, the luciferase activity of miR-142-3p mimic and wild-type HOXA5 3'-UTR was significantly lower than that of miR-142-3p negative control and wild-type HOXA5 3'-UTR (P<0.05). The proliferation of Nalm6 cells and the number of cell clones could be inhibited by miR-142-3p mimic after 48 and 72 hours of transfection (P<0.05), which causing G@*CONCLUSION@#MiR-142-3p can inhibit the proliferation of Nalm6 cells by targeting down-regulation the expression of HOXA5, arrest the G

Caracterización de los pacientes con leucemia aguda en un hospital de tercer nivel de Quito - Ecuador / Characterization of patients with acute leukemia in a third level hospital from Quito - Ecuador

INTRODUCCIÓN. Las leucemias agudas son neoplasias hematológicas primarias, carac-terizadas por la proliferación anormal de células inmaduras en la médula ósea. OBJETI-VO. Definir las características clínicas, demográficas, de laboratorio y citogenéticas de los pacientes diagnosticados con leucemias agudas; además sus complicaciones durante la inducción a la remisión. MATERIALES Y MÉTODOS. Estudio descriptivo, retrospectivo. La población fue de 191 pacientes con diagnóstico de leucemia aguda en la Unidad Téc-nica de Hematología del Hospital de Especialidades Carlos Andrade Marín entre enero 2016 y octubre 2018. Los datos fueron tomados de la Historia Clínica documentada en el sistema AS-400, el análisis descriptivo se realizó con el programa estadístico International Business Machines Statistical Package for the Social Sciences, Versión 25.0. RESULTA-DOS. La leucemia mieloide aguda fue diagnosticada en el 62,30% (118; 191), seguida de la leucemia linfoide aguda en el 34,00% (64; 191). La leucemia aguda fue más común en hombres en un 54,45% (103; 191) que en mujeres. Las alteraciones de laboratorio más frecuentes fueron la hiperleucocitosis, anemia y trombocitopenia. En el 37,50% (69; 184) de los casos se determinó un cariotipo normal, la alteración numérica más frecuente fue la hipoploidía. La complicación más constante durante la inducción fueron las infecciones; el microorganismo hallado en más del 80,00% de los cultivos fueron las bacterias. CON-CLUSIÓN. La leucemia mieloide aguda fue el tipo más común en la población adulta, posterior a la inducción existió alto porcentaje de mortalidad y bajo de remisión completa

INTRODUCTION. Acute leukemias are primary hematologic malignancies, characterized by abnormal proliferation of immature cells in the bone marrow. OBJECTIVE. Define the clinical, demographic, laboratory and cytogenetic characteristics of the patients diagnosed with acute leukemias; also its complications during induction to remission. MATERIALS AND METHODS. Descriptive, retrospective study. The population was 191 patients diag-nosed with acute leukemia in the Technical Unit of Hematology of the Carlos Andrade Marín Specialty Hospital between january 2016 and october 2018. Data were taken from the Clinical History documented in the AS-400 system, the descriptive analysis was perfor-med with the International Business Machines Statistical Package for the Social Sciences, Version 25.0. RESULTS. Acute myeloid leukemia was diagnosed in 62,30% (118; 191), followed by acute lymphoid leukemia at 34,00% (64; 191). Acute leukemia was more com-mon in men in 54,45% (103; 191) than in women. The most common laboratory disorders were hyperleukocytosis, anemia and thrombocytopenia. In 37,50% (69; 184) of cases, a normal karyotype was determined, the most frequent numerical alteration was hypoploidy. The most constant complication during induction were infections; the microorganism found in more than 80,00% of the cultures were bacteria. CONCLUSION. Acute myeloid leuke-mia was the most common type in the adult population, after induction there was a high percentage of mortality and a low rate of complete remission.

Clinical Efficacy of Humanized Anti-CD19 Chimeric Antigen Receptor T Cells in the Treatment of Acute B Lymphocytic Leukemia / 中国实验血液学杂志

OBJECTIVE@#To study the safety and effectiveness of humanized CD19-targeted CAR-T cells (hCART19s) for treatment of patients with refractory/relapsed (R/R) B-ALL.@*METHODS@#The analyzed patients were 15 children and adults with relapsed/refractory B-ALL who not received treatment with murine CD19 CAR-T cells. The patients received a single dose (1×10/kg) of autologous hCART19 infusion after lymphodepletion chemotherapy based on cyclophosphamide and fludarabine.@*RESULTS@#Among the 15 patients, 13/14 (92.9%) evaluable patients achieved complete remission (CR) or CR with incomplete recovery of blood cells (CRi) on day 30 after hCART19s infusion. At day 180 after the infusion, the overall survival rate was 73.3%, and the leukemia-free survival rate was 69.2%. The cumulative incidence of relapse was 24.5% and non-relapse mortality rate was 7.7%. During treatment,12/15 patients (80%) developed cytokine release syndrome (CRS) of grade 1-2, and 3 patients (20.0%) developed CRS of grade 3-5. Only one patient (6.7%) suffered from the reversible neurotoxicity.@*CONCLUSION@#hCART19s can effectively treat refractory/relapsed (R/R) adult and children with B-ALL, and the incidence of treatment-related CRS and neurotoxicity is low.

Silencing the PIK3CA Gene Enhances the Sensitivity of Childhood Leukemia Cells to Chemotherapy Drugs by Suppressing the Phosphorylation of Akt

PURPOSE: This study aimed to investigate the effects of PIK3CA on the sensitivity of acute B lymphocytic leukemia cells (Nalm-6 cells) to chemotherapy drugs. MATERIALS AND METHODS: Children's normal B lymphocytes and Nalm-6 cells were cultured. Nalm-6 cells were transfected with PIK3CA siRNA (siPIK3CA group) or its negative control (PIK3CA-Control group). Normal Nalm-6 cells were named Mock group. Nalm-6 cells transfected by PIK3CA siRNA were treated with Akt inhibitor (siPIK3CA+Akti-1/2 group). mRNA and protein expression was detected by qRT-PCR and Western blot. Proliferation and sensitivity to chemotherapeutic drugs was detected by MTT assay. Cell cycle and apoptosis was explored by low cytometry. Transwell assay was performed to test invasion. RESULTS: PIK3CA mRNA (p=0.008) and protein (p=0.006) expression was higher in Nalm-6 cells than that in normal B lymphocytes. Compared with the Mock group and PIK3CA-Control group, Nalm-6 cells of the siPIK3CA group had lower OD495 values (all p < 0.05) and invasion cell numbers (p=0.03 and p=0.025), as well as a higher proportion of G0/G1 phase cells (p=0.020 and p=0.022), percentage of apoptosis (p=0.016 and p=0.022), and inhibition rate (all p < 0.05). pAkt expression in the siPIK3CA group (p=0.026 and p=0.031) and siPIK3CA+Akti-1/2 group (p=0.019 and p=0.023) was lower than that in the Mock group. CONCLUSION: PIK3CA silencing inhibited Nalm-6 cell proliferation and invasion, and promoted their apoptosis and sensitivity to chemotherapeutic drugs, potentially through regulation of the PI3K/AKT signaling pathway.

Sobrevida global de pacientes con leucemia aguda en el Hospital de Especialidades Pediátricas de Chiapas, México / Childhood acute leukemia overall survival at the Hospital de Especialidades Pediátricas in Chiapas, México

Resumen: Introducción: A 10 años de la fundación del Hospital de Especialidades Pediátricas en Chiapas, México, es importante valorar la sobrevida global a 5 años de los pacientes con leucemia aguda bajo el régimen del Seguro Popular. Métodos: Estudio descriptivo y de sobrevida de 210 casos de leucemia aguda diagnosticados y tratados entre 2008 y 2012. Empleando curvas de Kaplan-Meier se analizó cada variedad de la enfermedad (B, T y mieloide), y para la leucemia B en función del grupo de riesgo, el sexo, la edad, los leucocitos al diagnóstico, los marcadores de superficie, el índice de DNA, el cariotipo y las translocaciones. Resultados: La edad, el sexo y la proporción de tipos de leucemia aguda (B = 85%; M = 10%; T = 5%) fueron similares al resto del país. El 20% de los pacientes estaban vivos a 5 años; el 53% habían fallecido y el 27% abandonaron el tratamiento. La sobrevida global a 5 años fue del 42% (B = 45%; T = 20%; M = 10%) (mediana: 38.8 meses; intervalo de confianza del 95%: 28.9-48.7). La mediana de «muy alto riesgo¼ fue de 7.7 contra 47 meses; no hubo diferencia entre riesgo habitual y alto riesgo. Los leucocitos < 50,000/µl al diagnóstico y CD10 positivo se asociaron con mejor sobrevida. En el momento del deceso, el 29% se encontraba en remisión. Conclusiones: La sobrevida de la leucemia aguda bajo el Seguro Popular fue desfavorable los primeros 5 años del Hospital de Especialidades Pediátricas. Se identificaron como contribuyentes la alta tasa de mortalidad temprana, de pacientes en remisión y el abandono. Además de revisar la atención médica, se requiere el estudio de elementos extrahospitalarios determinantes del abandono para mejorar el programa.

Abstract: Background: At the 10th anniversary of the Hospital de Especialidades Pediátricas in Chiapas, Mexico, it was important to assess the 5-year acute leukemia overall survival under the Seguro Popular program (Popular Insurance). Methods: A descriptive and survival study of 210 acute leukemia patients diagnosed and treated during 2008-2012 was performed. Kaplan-Meier survival curves were developed for all patients, each leukemia type (B, T and myeloid) and for B type related to risk group, age, sex, leukocytes, cell markers, DNA index, karyotype, and translocations. Results: Age, gender and proportion of leukemia types (B = 85%; M = 10%; T = 5%), were similar to other parts of the country. At the end of the 5-year treatment, 20% of the patients were alive, 53% had died and 27% had abandoned the treatment. Global survival was 42% (B = 45%; T = 20%; M = 10%) (median: 38.8 months; confidence interval of 95% = 28.9-48.7). Very high-risk median survival was 7.7 versus 47 months. There was no difference between standard and high-risk groups. The initial leukocyte count < 50,000/µL and CD10 positive were related to better B survival; no other variables were related. At the time of death, 29% of patients were in remission. Conclusions: Global survival of acute leukemia at Hospital de Especialidades Pediátricas under the Seguro Popular during its first 5 years was surprisingly poor given the medical resources available through the insurance. Early mortality, death during remission and high desertion rates contributed to these results. A detailed revision of treatment protocols and reasons for abandoning treatment is mandatory.

Ki-67 expression in mature B-cell neoplasms: a flow cytometry study

SUMMARY OBJECTIVE: Ki-67 is a nuclear protein associated with cellular proliferation in normal or leukemic conditions that can help identify more aggressive diseases and is usually evaluated with immunohistochemistry. The aim of this was to assess Ki-67 expression on mature B-cell neoplasms samples with flow cytometry immunophenotyping. METHOD: After surface staining with CD19 and CD45, intracellular staining for Ki-67 was performed in leukemic mature B-cells. Ki-67 expression was evaluated with flow cytometry. RESULTS: Ki-67 expression was higher in mantle cell lymphoma, Burkitt lymphoma, and diffuse large B-cell lymphoma cases. It was also associated with CD38 mean fluorescence intensity. CONCLUSIONS: Ki-67 expression evaluated by flow cytometry can be a useful tool in the diagnosis of mature B-cell neoplasms. More studies are needed to validate Ki-67 assessment with flow cytometry immunophenotyping.

RESUMO OBJETIVO: Ki-67 é uma proteína nuclear associada à proliferação celular em condições normais ou leucêmicas que pode ajudar a Identificar doenças mais agressivas. Este marcador é geralmente avaliado com imuno-histoquímica. O objetivo deste estudo foi avaliar a expressão de Ki-67 em amostras de neoplasias de células B maduras com imunofenotipagem por citometria de fluxo. MÉTODO: Após marcação de superfície com CD19 e CD45, foi realizada marcação intracelular para Ki-67 em células B maduras leucémicas. A expressão de Ki-67 foi avaliada por citometria de fluxo. RESULTADOS: A expressão de Ki-67 foi maior em células de linfomas de manto, linfoma de Burkitt e linfoma difuso de grandes células B. Também houve associação de Ki-67 à intensidade de fluorescência média de CD38. CONCLUSÃO: A expressão de Ki-67 avaliada por citometria de fluxo pode ser útil no diagnóstico de neoplasias de células B maduras. São necessários mais estudos para validar a avaliação de Ki-67 com Imunofenotipagem por citometria de fluxo.