A History and Current Understanding of Acute Erythroid Leukemia.

Acute erythroid leukemia (AEL) is a highly aggressive subtype of acute myeloid leukemia. Since the first recognition of an erythroid-predominant hematologic malignancy in the early 20th century, AEL has gone through a turnstile of changing definitions and nomenclature, including eritoleucemia, erythremic myelosis, AML-M6 and pure erythroid leukemia. Ever-changing diagnostic criteria and under recognition have stifled our understanding of, and therapeutic options for, this rare erythroid-predominant myeloid neoplasm. It is now well-documented that true AEL, which is characterized primarily by immature erythroid proliferation, often harbors highly complex cytogenetic changes and multiple, deleterious TP53 mutations. These cytogenetic and molecular characteristics render current treatment approaches largely ineffective, and signal an urgent need for novel therapeutic modalities. Due to its rarity and aggressive nature, concerted collaborative efforts must be undertaken in order to improve the outcomes and treatment options for patients with AEL.

Immunophenotypical profiling of myeloid neoplasms with erythroid predominance using mass cytometry (CyTOF).

Acute erythroid leukemia (AEL) is a disease continuum between Myelodysplastic syndrome (MDS) and Acute myeloid leukemia (AML) with the cellular hallmark of uncontrolled proliferation and impaired differentiation of erythroid progenitor cells. First described by Giovanni di Guglielmo in 1917 AEL accounts for less than 5% of all de novo AML cases. There have been efforts to characterize AEL at a molecular level, describing recurrent alterations in TP53, NPM1 and FLT3 genes. A genomic analysis of AEL cases confirmed its complexity. Despite these advances, the biology underlying erythroid proliferations remains unclear and the prognosis is dismal with a median survival of only 3 months for pure erythroid leukemia (PEL). Marker combinations suitable for the identification and characterization of leukemic stem cell (LSC) candidates, monitoring measurable residual disease (MRD) during chemotherapy treatment and the development of innovative targeted therapies are missing. Here, we developed a mass cytometry panel for an in-depth characterization of erythroid and myeloid blast cell populations from human AEL bone marrow samples in comparison to other AML subtypes and healthy counterparts. A total of 8 AEL samples were analyzed and compared to 28 AML samples from different molecular subtypes, healthy bone marrow counterparts (n = 5) and umbilical cord blood (n = 6) using high-dimensional mass cytometry. Identification of erythroid and myeloid blast populations in high-dimensional mass cytometry data enabled a refined view on erythroblast differentiation stages present in AEL erythroid blasts and revealed immunophenotypical profiles specific to AEL. Profiling of phenotypic LSCs revealed aberrant erythroid marker expression in the CD34+ CD38- stem cell compartment. In addition, the identification of novel candidate surface marker combinations and aberrancies might enhance clinical diagnostics of AEL. We present a high-parameter mass cytometry approach feasible for immunophenotypical analysis of blast and stem cell populations in myeloid neoplasms with erythroid predominance laying the foundation for more precise experimental approaches in the future.

Pure (acute) erythroid leukemia: morphology, immunophenotype, cytogenetics, mutations, treatment details, and survival data among 41 Mayo Clinic cases.

Pure erythroid leukemia (PEL), also known as acute erythroid leukemia (AEL), is recognized as a distinct morphologic entity by both the 2016 and 2022 World Health Organization (WHO) classification system. By contrast, the 2022 International Consensus Classification (ICC) includes PEL under a broader category of "acute myeloid leukemia with mutated TP53". We identified 41 Mayo Clinic cases of PEL (mean age 66 years, range 27-86; 71% males) and provide a comprehensive account of bone marrow morphology, immunophenotype, cytogenetic and mutation profiles. PEL was primary in 14 cases, therapy-related in 14, secondary in 12, and undetermined in one. All cases expressed biallelic TP53 alterations, including TP53 deletion/single TP53 mutation (68%), two TP53 mutations (29%) or two TP53 deletions (3%); additional mutations were infrequent. Karyotype was complex in all cases and monosomal in 90%. Treatment details were available in 29 patients: hypomethylating agent (HMA) alone (n = 5), HMA + venetoclax (n = 12), intensive chemotherapy (n = 4), supportive care/other (n = 8); no responses or allogeneic stem cell transplants were documented, and all patients died at a median 1.8 months (range 0.2-9.3). The current study highlights a consistent and reproducible set of morphologic and genetic characteristics that identify PEL as a distinct AML variant whose dismal prognosis requires urgent attention.

Engineering genetic devices for in vivo control of therapeutic T cell activity triggered by the dietary molecule resveratrol.

Chimeric antigen receptor (CAR)-engineered T cell therapies have been recognized as powerful strategies in cancer immunotherapy; however, the clinical application of CAR-T is currently constrained by severe adverse effects in patients, caused by excessive cytotoxic activity and poor T cell control. Herein, we harnessed a dietary molecule resveratrol (RES)-responsive transactivator and a transrepressor to develop a repressible transgene expression (RESrep) device and an inducible transgene expression (RESind) device, respectively. After optimization, these tools enabled the control of CAR expression and CAR-mediated antitumor function in engineered human cells. We demonstrated that a resveratrol-repressible CAR expression (RESrep-CAR) device can effectively inhibit T cell activation upon resveratrol administration in primary T cells and a xenograft tumor mouse model. Additionally, we exhibit how a resveratrol-inducible CAR expression (RESind-CAR) device can achieve fine-tuned and reversible control over T cell activation via a resveratrol-titratable mechanism. Furthermore, our results revealed that the presence of RES can activate RESind-CAR T cells with strong anticancer cytotoxicity against cells in vitro and in vivo. Our study demonstrates the utility of RESrep and RESind devices as effective tools for transgene expression and illustrates the potential of RESrep-CAR and RESind-CAR devices to enhance patient safety in precision cancer immunotherapies.

Optimized cytotoxicity assay for co-suspended effector and target cells.

In recent years, adoptive cell therapy of immune effector cells, such as chimeric antigen receptor-T (CAR-T) cells, natural killer (NK) cells, and epitope-specific cytotoxic T lymphocyte (CTL) cells have been employed in clinical trials. In addition, CD19 CAR-T cells have been approved by the FDA for treatment of non-Hodgkin lymphoma and diffuse large B-cell lymphoma. In this context, it is vital to detect cellular cytotoxicity and monitor the quality of ex vivo expanded immune cells before product release and patient infusion. Target cells could proliferate in parallel with effector cells during the cytotoxicity assay, making it difficult to estimate the death ratio using conventional approaches. Meanwhile, non-specific dyes or non-homogeneous biomarkers for target cells may interfere with the final readout post addition of effector cells. Here, we modified a component of the coincubation medium to suppress the spontaneous release of bis(acetoxymethyl)2,2':6',2″-terpyridine-6,6″-dicarboxylate and sustained the window at a stable range (~70%). Further, the optimized Eu-TDA method presented reliable outcomes compared with lactate dehydrogenase detection and was compatible with cytotoxicity tests for NK cells and specific CTLs. Finally, the reported assay can accurately detect death of target cells depending on the amount of hydrophilic complex and can be reliably applied in quality control and cell activity evaluation tests on co-suspended effector and target cells. SUMMARY: A medium component for cellular coincubations (and associated protocols) have been optimized and validated for cytotoxicity assays, which can reliably evaluate the potency of engineered CD19 CAR-T cells, NK cells, and specific CTLs. In particular, the reported method can be applied widely in routine assays for bi-suspended effector and target cells with a stable window.

First immunotherapeutic CAR-T cells against the immune checkpoint protein HLA-G.

BACKGROUND: CAR-T cells immunotherapy is a breakthrough in the treatment of hematological malignancies such as acute lymphoblastic leukemia (ALL) and B-cell malignancies. However, CAR-T therapies face major hurdles such as the lack of tumor-specific antigen (TSA), and immunosuppressive tumor microenvironment sometimes caused by the tumorous expression of immune checkpoints (ICPs) such as HLA-G. Indeed, HLA-G is remarkable because it is both a potent ICP and a TSA. HLA-G tumor expression causes immune escape by impairing innate and adaptive immune responses and by inducing a suppressive microenvironment. Yet, to date, no immunotherapy targets it. METHODS: We have developed two anti-HLA-G third-generation CARs based on new anti-HLA-G monoclonal antibodies. RESULTS: Anti-HLA-G CAR-T cells were specific for immunosuppressive HLA-G isoforms. HLA-G-activated CAR-T cells polarized toward T helper 1, and became cytotoxic against HLA-G+ tumor cells. In vivo, anti-HLA-G CAR-T cells were able to control and eliminate HLA-G+ tumor cells. The interaction of tumor-HLA-G with interleukin (IL)T2-expressing T cells is known to result in effector T cell functional inhibition, but anti-HLA-G CAR-T cells were insensitive to this inhibition and still exerted their function even when expressing ILT2. Lastly, we show that anti-HLA-G CAR-T cells differentiated into long-term memory effector cells, and seemed not to lose function even after repeated stimulation by HLA-G-expressing tumor cells. CONCLUSION: We report for the first time that HLA-G, which is both a TSA and an ICP, constitutes a valid target for CAR-T cell therapy to specifically target and eliminate both tumor cells and HLA-G+ suppressive cells.

Eritroleucemias: Recategorización según criterios de la organización mundial de la salud / Erythroleukemias. Recategorization according to the World Health Organization's criteria

La leucemia aguda es la enfermedad oncológica más frecuente en la infancia. La leucemia linfoblástica aguda representa el 75% y la mieloblástica aguda el 25% de ellas. La eritroleucemia es una entidad infrecuente, representando menos del 5% de las leucemias mieloblásticas agudas. Su definición ha variado a lo largo del tiempo. La OMS en 2017 define el subtipo de eritroleucemia cuando el porcentaje de eritroblastos representa el 80% de la celularidad total de la médula ósea. El presente trabajo, de tipo analítico, retrospectivo, tuvo como finalidad revisar los hallazgos de morfología, citometría de flujo, citogenética, respuesta al tratamiento y evolución de los casos previamente definidos como eritroleucemia, en nuestro centro, en los últimos 25 años y reclasificar aquellos que no cumplían con los nuevos criterios de la OMS 2017. Entre enero de 1990 y diciembre de 2015, se diagnosticaron 576 casos de leucemia mieloblástica aguda siendo 11 (1.9%) de ellos clasificados como eritroleucemia. Resultaron evaluables 10 casos. La distribución por sexo fue 1:1 y la edad mediana fue 5 (rango: 0.9-14) años. Seis pacientes presentaban antecedentes de síndrome mielodisplásico. Según los nuevos criterios, ninguno de los casos analizados puede ser actualmente definido como eritroleucemia. De acuerdo a la recategorización, fueron definidos como leucemias de subtipos de mal pronóstico, como leucemia aguda indiferenciada, sin diferenciación y megacarioblástica. Solo dos pacientes se encuentran libres de enfermedad, probablemente debido a estos subtipos desfavorables, sumado al antecedente frecuente de mielodisplasia.

Acute leukemia is the most frequent malignant disease in childhood. Acute lymphoblastic leukemia represents 75% and acute myeloblastic leukemia 25% of them. Erythroleukemia is a rare entity, corresponding to less than 5% of acute myeloblastic leukemia. Its definition has changed over the time. WHO in 2017 defines erythroleukemia when the percentage of erythroblasts represent 80% of the total cellularity of the bone marrow aspirate. This analytical and retrospective study was performed with the aim of reviewing morphology, flow cytometry and cytogenetic features, response to treatment and outcome of cases previously defined as erythroleukemia in our center during the last 25 years and, in addition to reclassify those cases which do not meet the new WHO 2017 criteria. From January 1990 to December 2015, 576 patients were diagnosed as acute myeloblastic leukemia and 11 (1.9%) of them were classified as erythroleukemia. Ten cases were evaluable. Sex distribution was 1:1 and the median age at diagnosis was 5 (range: 0.9-14) years. Six of them had presented with previous myelodysplastic syndrome. None of the analyzed cases can be currently defined as erythroleukemia, according to the new criteria. When reclassified, the cases were defined as leukemias of subsets with poor prognosis such as acute undifferentiated leukemia, without differentiation and megakaryoblastic leukemia. Only 2 patients remain leukemia-free and this could be explained both by the unfavorable prognosis of these leukemia subtypes, and the antecedent of myelodysplastic syndrome in most of the cases.

[Erythroleukemias. Recategorization according to the World Health Organization's criteria]. / Eritroleucemias. Recategorización según criterios de la Organización Mundial de la Salud.

Acute leukemia is the most frequent malignant disease in childhood. Acute lymphoblastic leukemia represents 75% and acute myeloblastic leukemia 25% of them. Erythroleukemia is a rare entity, corresponding to less than 5% of acute myeloblastic leukemia. Its definition has changed over the time. WHO in 2017 defines erythroleukemia when the percentage of erythroblasts represent 80% of the total cellularity of the bone marrow aspirate. This analytical and retrospective study was performed with the aim of reviewing morphology, flow cytometry and cytogenetic features, response to treatment and outcome of cases previously defined as erythroleukemia in our center during the last 25 years and, in addition to reclassify those cases which do not meet the new WHO 2017 criteria. From January 1990 to December 2015, 576 patients were diagnosed as acute myeloblastic leukemia and 11 (1.9%) of them were classified as erythroleukemia. Ten cases were evaluable. Sex distribution was 1:1 and the median age at diagnosis was 5 (range: 0.9-14) years. Six of them had presented with previous myelodysplastic syndrome. None of the analyzed cases can be currently defined as erythroleukemia, according to the new criteria. When reclassified, the cases were defined as leukemias of subsets with poor prognosis such as acute undifferentiated leukemia, without differentiation and megakaryoblastic leukemia. Only 2 patients remain leukemia-free and this could be explained both by the unfavorable prognosis of these leukemia subtypes, and the antecedent of myelodysplastic syndrome in most of the cases.

Erythroleukemia-historical perspectives and recent advances in diagnosis and management.

Acute erythroleukemia is a rare form of acute myeloid leukemia recognized by its distinct phenotypic attribute of erythroblastic proliferation. After a century of its descriptive history, many diagnostic, prognostic, and therapeutic implications relating to this unique leukemia subset remain uncertain. The rarity of the disease and the simultaneous involvement of its associated myeloid compartment have complicated in vitro studies of human erythroleukemia cell lines. Although murine and cell line erythroleukemia models have provided valuable insights into pathophysiology, translation of these concepts into treatment are not forthcoming. Integration of knowledge gained through a careful study of these models with more recent data emerging from molecular characterization will help elucidate key mechanistic pathways and provide a much needed framework that accounts for erythroid lineage-specific attributes. In this article, we discuss the evolving diagnostic concept of erythroleukemia, translational aspects of its pathophysiology, and promising therapeutic targets through an appraisal of the current literature.

Comparison of anticancer effect of Pleurotus ostreatus extract with doxorubicin hydrochloride alone and plus thermotherapy on erythroleukemia cell line.

Background Recent studies have introduced Pleurotus ostreatus (Pleurotaceae) as a herbal medicine for treating different types of cancer. This survey utilizes P. ostreatus and doxorubicin hydrochloride (DOX) alone and then with hyperthermia to investigate the erythroleukemia cell line. This study evaluates and compares the apoptotic and necrotic effects of various treatments on the KG-1 cell line. Methods The proliferation of KG-1 cells was measured by using a tetrazolium salt (MTT)-based colorimetric assay during 96 h after treatment by gradient dilutions of 100 ng/mL to 100 mg/mL of P. ostreatus methanol extract and then the minimum inhibitory concentration (MIC) was determined and was applied in additional experiments. Afterward, the cells were treated using P. ostreatus extract, DOX (6.95 mg/L), and hyperthermia (42 and 44 °C), separately and then applying hyperthermia. Finally, the ratios of apoptosis and necrosis after 24 h incubation were evaluated by using flow cytometry. Results The MIC of the extract was determined (1 mg/mL), which significantly increased the ratio of apoptosis rather than necrosis, whereas the DOX treatment primarily induced necrosis on the KG-1 cells. The anticancer effects of the mushroom extract were significantly increased when it was combined with thermotherapy, which exhibited apoptotic effects at 42 °C but induced necrosis at 44 °C. Conclusions The results suggest that P. ostreatus extract induces apoptosis on KG-1 cells and its anticancer effects are significantly increased in combination with thermotherapy. Therefore, P. ostreatus could be considered as an alternative with anticancer effect for further studies in erythroleukemia patients.

An analysis of 97 previously diagnosed de novo adult acute erythroid leukemia patients following the 2016 revision to World Health Organization classification.

BACKGROUND: The incidence of acute erythroid leukemia subtype (AEL) is rare, accounting for 5% of cases of acute myeloid leukemia (AML), and the outcome is dismal. However, in 2016 revision to the WHO classification, the subcategory of AEL has been removed. Myeloblasts are redefined as the percentage of total marrow cells, not non-erythroid cells. Therefore, the previously diagnosed AEL cases are currently diagnosed as AML or myelodyspalstic syndrome (MDS) according to new criteria. METHODS: We respectively reviewed cases of 97 de novo previously diagnosed AEL and all the patients were diagnosed as AML or MDS according to the new classification scheme, and then the clinical characteristics of these two subtypes were compared. Statistical analyses were performed by SPSS software version 18.0. RESULTS: The median age was 37 years-old, the two-thirds of previous AEL cases were diagnosed as MDS, and there was no obvious difference between two subtypes except for male/female ratio and age. Cytogenetic, rather than MDS/AML subtypes, can better represent the prognostic factor of previously diagnosed AEL patients. When the cytogenetic risk of patients belonged to MRC intermediate category and age were below 40 years-old in previous AEL cases, the patients who received induction chemotherapy without transplantation had a similar survival compared with the patients who underwent transplantation (3-year OS: 67.2% vs 68.5%). CONCLUSIONS: Cytogenetic, rather than MDS/AML subtypes, can better represent the prognostic factor of previously diagnosed AEL patients. Transplantation was a better choice for those whose cytogenetic category was unfavorable.

Retroviral gene transfer into primary human NK cells activated by IL-2 and K562 feeder cells expressing membrane-bound IL-21.

Natural killer (NK) cells are capable of rapidly recognizing and efficiently killing tumor cells. This makes them a potentially promising agent for cancer immunotherapy. Additional genetic modifications of NK cells may further improve their anti-tumor efficacy. Numerous technical challenges associated with gene delivery into NK cells have significantly tempered this approach. We achieved efficient retroviral vector transduction of primary human NK cells that were stimulated by a combination of IL-2 and engineered K562 cells expressing membrane-bound IL-21. The activated NK cells were in less differentiated state and expressed NK cell activation receptors NKG2D, NKp30, CD16, and were highly HLA-DR-positive. This NK cell population was highly susceptible to the transduction by both GFP- and NGFR-expressing retroviral vectors, with transduction efficiency exceeding 50%. More mature CD57+ NK cell population was generally resistant to retroviral vector transduction because of poor response to the stimulation. Our findings may facilitate retroviral vector-mediated genetic engineering of human primary NK cells for future immunotherapies.

[Biological Characteristics and Therapeutic Efficacy of 103 Patients with Acute Erythroleukemia].

OBJECTIVE: To investigate the biological characteristics and therapeutic efficacyt of acute erythroleukemia (AEL,AML-M6). METHODS: Blood cell count, liver function, lactate dehydrogenase level, coagulation, morphology, immunology, cell genetics and molecular biology were retrospectively analyzed in 103 cases of acute erythroleukemia patients admitted in our department from May 2016 to June 2009. The therapeutic efficacy was observed by means of remission rate, relapse rate, relapse-free survival and overall survival. RESULTS: The medians of white blood cells, granulocyte, hemoglobin and platelet were 3.04×109/L, 0.67×109/L, 66 g/L, and 45×109/L,respectively. Nucleated red blood cells were found in the peripheral blood smears from 71.1% of AEL patients. None of the patients showed abnormal coagulation function. Flow cytometry analysis indicated that CD13 (93.5%),CD117(89.1%), HLA-DR(87.0%), and CD34 (80.0%) were highly expressed in AEL, and lymphoid antigens of CD4 (42.9%) and CD7(28.9%) were expressed in partial patients. Karyotype analysis in 82 patients showed 52.4% (43/82) normal karyotype, 41.5% (34/82) abnormal karyotype, and 6.1% (5/82) failed tests. In the 34 cases with abnormal karyotype, there were 14(41.2%) cases with simple chromosomal abnomality and 20(58.8%) cases with complex karyotype. The positive rate of fusion gene accounted for 16.7% in 60 patients, and the gene mutations accounted for 77.8% in 27 patients. Among 103 cases of AEL, 81 cases were treated with chemotherapy, but 66 cases can be used for therapeutic analysis, as a results the total complete remission rate derived from 2 courses of treatment was 45.5% (30/66). The relapse rate was 36.7% (11/30), and the median relapse time was 15.5 months (6.2-50 months). The median survival time of 66 patients for therapeutic analysis was 29 months. The median survival time of CR patients was very significantly longer than that of the non-CR patients(P=0.001). The 5 year survival rate of CR patients was 65%, the median time of relapse-free survival (RFS) was 46.2 months and 3-years RFS was 58%. CONCLUSION: AEL is characterized by the highly expressed CD34 antigen, and complex karyotype. Although AEL has lower CR rate and poor prognosis, CR patients can achieve long-term survival and have good quality of life.

Congenital immature pure erythroid leukemia with E-cadherin expression.

Congenital pure erythroid leukemia is exceedingly rare and poses a diagnostic challenge. We report an atypical case of congenital pure erythroid leukemia that did not express typical erythroid markers. The patient presented with a high white blood cell count with blastic cells at birth. Although flow cytometric analyses of peripheral blood and bone marrow showed a large CD45-negative cell population, we did not identify any evidence of monoclonality. While the circulating blasts decreased with only supportive care, hepatomegaly with multiple nodules was accompanied by liver failure, disseminated intravascular coagulation, and development of hemophagocytic lymphohistiocytosis. Pathological examination of the liver biopsy specimen revealed a small round cell tumor that was negative for nearly all hematopoietic cell markers, including classical erythroid cell markers, and positive for CD43, CD71, and E-cadherin, an early erythroid marker epithelial calcium-dependent adhesion protein, suggesting that these tumor cells originated from an immature erythroblast. We found high ß-catenin and c-Myc protein expression, which were not previously described in pure erythroid leukemia. Cytosine arabinoside temporarily alleviated clinical symptoms; however, the patient died of progressive disease at 8 months of age. This case indicates that E-cadherin is useful for diagnosing pure erythroid leukemia, even in immature cases.

The uniqueness of morphological features of pure erythroid leukemia in myeloid neoplasm with erythroid predominance: A reassessment using criteria revised in the 2016 World Health Organization classification.

We reviewed 97 consecutive cases of myeloid neoplasm with erythroid predominance (MN-EP) between 2000 and 2015. Following 2016 WHO classification, MN-EP patients were classified into four groups. Eight pure erythroid leukemia (PEL) (including t-MN and AML-MRC morphologically fulfilled criteria for PEL) patients had dismal outcomes (median OS: 1 month) and showed more bone marrow fibrosis, worse performance status (PS) and higher serum lactate dehydrogenase (LDH) at diagnosis than the other groups. In the univariate analysis, risks of death in MN-EP patients included the morphologic features of PEL, very poor cytogenetic risk by IPSS-R, bone marrow fibrosis, leukocytosis, anemia, hypoalbuminemia, high LDH, and poor PS. In the multivariate analysis, independent predictors of death were morphologic features of PEL (adjusted hazards ratio [HR] 3.48, 95% confidence interval [CI] 1.24-9.74, p = 0.018), very poor cytogenetic risk by IPSS-R (adjusted HR 2.73, 95% CI 1.22-6.10, p = 0.015), hypoalbuminemia (< 3.7 g/dl) (adjusted HR 2.33, 95% CI 1.10-4.91, p = 0.026) and high serum LDH (≥ 250 U/L) (adjusted HR 2.36, 95% CI 1.28-4.36, p = 0.006). Poor or unfavorable risk in different cytogenetic risk systems independently predicted death and UKMRC-R was the best model.

RNAi-mediated knockdown of MCM7 gene on CML cells and its therapeutic potential for leukemia.

MCM7 is one of the subunits of MCM2-7 complex, which is essential to DNA replication licensing and the control of cell cycle progression. It has been demonstrated that MCM7 participates in mRNA transcription and DNA damage regulation as well. MCM7 gene is found to be over-expressed in multiple cancers, but there are few reports about its effect in leukemia. Recent studies have proven that MCM7 expression has a relationship with diagnosis and prognosis, which has led to their potential clinical application as a marker for cancer screening. RNA interference (RNAi) is a biological process in which RNA molecules inhibit gene expression, typically by causing the destruction of specific mRNA molecules. It is a valuable research tool, which is widely used in cell culture and living organisms as well as in medicine recent years. It is indicated that RNAi application for targeting functional carcinogenic molecules, tumor resistance to chemotherapy and radiotherapy is required in cancer treatment. Gene products knockdown by RNAi technology exerts anti-proliferative and pro-apoptotic effects upon cell culture systems, animal models and in clinical trials in the most studies. In the present study, we found that MCM7 highly expressed in K562 cells rather than that in normal neutrophils. Thus, lentivirus-mediated shRNA targeting MCM7 was used to suppress its endogenous expression in K562 cells and develop a novel therapeutic strategy for leukemia.

Acute megakaryoblastic leukemia, unlike acute erythroid leukemia, predicts an unfavorable outcome after allogeneic HSCT.

Acute erythroid leukemia (FAB-M6) and acute megakaryoblastic leukemia (FAB-M7) exhibit closely related properties in cells regarding morphology and the gene expression profile. Although allogeneic hematopoietic stem cell transplantation (allo-HSCT) is considered the mainstay of the treatment for both subtypes of leukemia due to their refractoriness to chemotherapy and high rates of relapse, it remains unclear whether allo-HSCT is curative in such cases due to their scarcity. We retrospectively examined the impact of allo-HSCT in 382 patients with M6 and 108 patients with M7 using nationwide HSCT data and found the overall survival (OS) and relapse rates of the M6 patients to be significantly better than those of the M7 patients after adjusting for confounding factors and statistically comparable with those of the patients with M0/M1/M2/M4/M5 disease. Consequently, the factors of age, gender, performance status, karyotype, disease status at HSCT and development of graft-vs.-host disease predicted the OS for the M6 patients, while the performance status and disease status at HSCT were predictive of the OS for the M7 patients. These findings substantiate the importance of distinguishing between M6 and M7 in the HSCT setting and suggest that unknown mechanisms influence the HSCT outcomes of these closely related subtypes of leukemia.

Citosina Arabinósido 100 mg y 500 mg en solución / Cytosine Arabinoside 100 mg and 500 mg in solution

FORMA FARMACÉUTICA: bulbo DENOMINACIÓN COMÚN INTERNACIONAL: arabinósido de citosina. COMPOSICIÓN: cada bulbo contiene 100 mg y 500 mg de arabinósido de citosina en solución. CATEGORÍA FARMACOLÓGICA: antineoplásico, agente citotóxico, antimetabolito, analógo de las pirimidinas. FARMACOCINÉTICA: la biodisponibilidad por VO es escasa (menor que 20 %). La distribución es amplia y rápida por los tejidos. Atraviesa las barreras placentarias y hematoencefálica, alcanza el LCR hasta 40‒50 por ciento de la concentración plasmática. Es metabolizado por citidina desaminasa, dando lugar fundamentalmente a arabinósido de uracilo, que es un metabolito inactivo y a trifosfato de aracitidina (activo). La desaminación se produce en el hígado, plasma y tejidos periféricos. Se elimina por la orina (± 80 por ciento) en las primeras 24 h. La vida media de eliminación terminal es 1-3 h. INDICACIONES: leucemia linfocítica y mielocítica aguda y leucemia meníngea. También se emplea en esquemas de segunda o tercera línea de linfomas no Hodgkin y leucemia mieloide crónica. Eritroleucemia. CONTRAINDICACIONES: hipersensibilidad conocida a la citosina. Pacientes con depresión de la médula ósea, enfermedades debilitantes e infecciones virales recientes como varicela o herpes zoster. USO EN POBLACIONES ESPECIALES: LM: datos no disponibles. E: categoría de riesgo D PRECAUCIONES: LM: no se conoce su excreción por la leche humana; no obstante, se recomienda suspender la lactancia materna durante la administración del fármaco. CARCINOGENICIDAD: grupo de riesgo 3. Los efectos depresores de la médula ósea de la citarabina pueden dar lugar a un aumento de la incidencia de infecciones, retardo en la cicatrización y hemorragia gingival. Deben ser cuidadosamente monitoreados los recuentos hemáticos. Si el recuento de leucocitos arroja CAN menor que 1 000 células/mm3 y las plaquetas están por debajo de 50 000 celulas/mm3, el tratamiento debe ser interrumpido. Los valores pueden continuar bajando aún después de que la administración de citarabina sea suspendida. El tratamiento puede reiniciarse cuando existen signos evidentes de recuperación de la médula ósea. Cuando se administran de forma rápida altas dosis por vía IV, los pacientes pueden presentar náusea y vómito durante algunas horas después de la inyección; este problema se presenta en forma menos severa cuando se administra por infusión. En pacientes con enfermedad hepática previa se deberán suministrar dosis menores de citosina, ya que en el hígado ocurre el proceso de detoxificación de este medicamento. Cuando tiene lugar una lisis celular rápida, se deben tomar las debidas precauciones para evitar hiperuricemia y hiperuricosuria y el riesgo de nefropatía por ácido úrico. La neurotoxicidad está asociada con los tratamientos de altas dosis y pueden presentarse como: toxicidad cerebelar aguda o puede ser severa con convulsiones y/o coma, incluso suele ser retardada, hasta 3‒8 días después que el tratamiento haya comenzado. El riesgo de toxicidad cerebelar se incrementa cuando el aclaramiento de creatinina sea inferior a 60 mL/min, edad mayor de 50 años, lesión preexistente del SNC y niveles de fosfatasa alcalina mayor que tres veces el límite superior normal. La conjuntivitis es prevenida y tratada con gotas de solución salina y/o corticosteroides. Como profilaxis, las gotas oculares deben comenzarse de 6 a 12 h antes de iniciar el tratamiento con la citarabina, y continuar hasta 24 h después de haber finalizado esta. El término de altas dosis se define como dosis IV de 2 a 3 g/m2/dosis, cada 12‒24 h, por 4‒12 dosis o de 36 g/m2 en monoterapia, generalmente combinado con otros agentes utilizados en tratamientos con altas dosis de quimioterapia. Puede presentarse el llamado síndrome de la citarabina que se caracteriza por fiebre, mialgia, dolor óseo, dolor torácico, rash maculopapular, astenia y conjuntivitis, puede ocurrir de 6 a 12 h después de la administración de la citarabina. Puede ser tratado de manera eficaz con...(AU)

Activation of microbubbles by low-level therapeutic ultrasound enhances the antitumor effects of doxorubicin.

OBJECTIVE: To prove that DNA damage, intracellular reactive oxygen species (ROS) generation and loss of mitochondrial membrane potential (MMP) are contributing factors for the inhibition of cell proliferation induced by doxorubicin (DOX) administration combined with microbubble-assisted low-level therapeutic ultrasound (US) in K562 cells. METHODS: 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide assay was adopted to examine cytotoxicity of different treatments. Changes on apoptosis and necrosis rates, DNA fragmentation, intracellular reactive oxygen species production, mitochondrial membrane potential, cellular membrane permeability and DOX-uptake were analysed by flow cytometry. Nuclear morphology changes were observed under a fluorescence microscope. Ultrasonic cavitation was measured by spectrofluorimetry. RESULTS: Under optimal conditions, MB-US significantly aggravated DOX-induced K562 cell death, especially necrosis, when compared with either monotherapy. Synergistic potentiation on DNA damage, ROS generation and MMP loss were observed. Ultrasonic cavitation effects, plasma membrane permeabilization and DOX-uptake were notably improved after MB-US exposure. CONCLUSIONS: MB-US could increase the susceptibility of tumours to antineoplastic drugs, suggesting a potential clinical method for US-mediated tumour chemotherapy. KEY POINTS: • Microbubble-ultrasound (MB-US) aggravated doxorubicin (DOX) induced K562 cell death, especially necrosis • MB-US synergistically potentiated DOX-initiated DNA damage, ROS generation and MMP loss • Ultrasonic cavitation effects, plasma membrane permeabilization and DOX-uptake were improved after treatment • MB-US holds significant potential for improving the efficacy of conventional chemotherapy.