Current management of newly diagnosed acute promyelocytic leukemia

Beyond Cisplatin: Combination Therapy with Arsenic Trioxide

Platinum drugs (cisplatin, oxaliplatin, and carboplatin) and arsenic trioxide are the only commercial inorganic non-radioactive anticancer drugs approved by the US Food and Drug Administration. Numerous efforts are underway to take advantage of the synergy between the anticancer activity of cisplatin and arsenic trioxide - two drugs with strikingly different mechanisms of action. These include co-encapsulation of the two drugs in novel nanoscale delivery systems as well as the development of small molecule agents that combine the activity of these two inorganic materials. Several of these new molecular entities containing Pt-As bonds have broad anticancer activity, are robust in physiological buffer solutions, and form stable complexes with biopolymers. This review summarizes results from a number of preclinical studies involving the combination of cisplatin and As2O3, co-encapsulation and nanoformulation efforts, and the chemistry and cytotoxicity of the first member of platinum anticancer agents with an arsenous acid moiety bound to the platinum(II) center: arsenoplatins.

Mutational landscape of patients with acute promyelocytic leukemia at diagnosis and relapse

Despite the high probability of cure of patients with acute promyelocytic leukemia (APL), mechanisms of relapse are still largely unclear. Mutational profiling at diagnosis and/or relapse may help to identify APL patients needing frequent molecular monitoring and early treatment intervention. Using an NGS approach including a 31 myeloid gene-panel, we tested BM samples of 44 APLs at the time of diagnosis, and of 31 at relapse. Mutations in PML and RARA genes were studied using a customized-NGS-RNA panel. Patients relapsing after ATRA-chemotherapy rarely had additional mutations (P = .009). In patients relapsing after ATRA/ATO, the PML gene was a preferential mutation target. We then evaluated the predictive value of mutations at APL diagnosis. A median of two mutations was detectable in 9/11 patients who later relapsed, vs one mutation in 21/33 patients who remained in CCR (P = .0032). This corresponded to a significantly lower risk of relapse in patients with one or less mutations (HR 0.046; 95% CI 0.011-0.197; P < .0001). NGS-analysis at the time of APL diagnosis may inform treatment decisions, including alternative treatments for cases with an unfavorable mutation profile.

Long-term follow-up of children with acute promyelocytic leukemia treated with Beijing Children's Hospital APL 2005 protocol (BCH-APL 2005)

We studied the outcomes of children with APL treated by the Beijing Children's Hospital's (BCH) acute promyelocytic leukemia (APL) 2005 protocol (BCH-APL2005). The clinical data of 77 patients enrolled from January 2005 to June 2015 were analyzed retrospectively. The hematologic complete remission (CR) rate and overall survival (OS) rate were evaluated between standard-risk (SR) and high-risk (HR) groups. Prognostic factors and complications were investigated in these two groups. CR in the SR and HR groups was 96.4% (54/56) and 85.7% (18/21), respectively, while the 10-year OS was 94.6% (53/56) and 76.2% (16/21), respectively. The cumulative incidence of early death was 6.5% (5/77), and the SR and HR groups were 1.8% (1/56) and 19.0% (4/21), respectively. Only two patients relapsed, and the relapse rate was 2.6% (2/77). According to Kaplan-Meier analysis, the SR group had a significantly better long-term survival than HR counterparts (p= .016). Initial leukocyte count was the only prognostic factor (p= .016) by univariate analysis, while other factors, such as FLT3-ITD and platelet count, had no correlation with prognosis. In addition, early deaths were mainly due to intracranial hemorrhage. Although the combination of all-trans retinoic acid (ATRA) and chemotherapy can improve the outcome of APL patients, the early deaths and anthracycline-related cardiac toxicity were relatively higher in our study. Current efforts focus on reducing or even avoiding chemotherapy in APL children and rest on the frontline regimen of intravenous arsenic trioxide or oral realgar-indigo naturalis formula plus ATRA, which is the direction for APL treatment.

Progressive hyperleukocytosis is a relevant predictive marker for differentiation syndrome, early death, and subsequent relapse in acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) is generally held to have favorable risk, but we have observed a high incidence of early deaths caused by fatal bleeding and differentiation syndrome (DS). We retrospectively analyzed 259 APL patients from 2002 to 2014 who all received all-trans retinoic acid (ATRA) with the support of sufficient transfusions, followed by 4 days of idarubicin. High-risk status was determined as a diagnostic leukocyte count (WBCdx) >10 × 10⁹/L (Sanz criteria). For patients with hyperleukocytosis, we sometimes conducted leukapheresis and also used hydroxyurea and prophylactic dexamethasone. Because we frequently observed patient fatalities from progressive hyperleukocytosis, we also checked the maximum leukocyte count (WBCmax) and stratified patients by their incremental ratios. The 8-week cumulative incidence of early death and DS was 13.5% and 17.8%, respectively. We found that WBCmax correlated better with early death and DS, even in the low-risk group, than WBCdx. Among the patients with WBCdx <10 × 10⁹/L, a WBCmax >43 × 10⁹/L correlated with early death (26.7%) and DS (40.0%). Also, having a WBCdx of 10 to 43 × 10⁹/La that increased to a WBCmax >43 × 10⁹/L correlated with increased early death (33.3%). The multivariate analysis revealed that a WBCmax >43 × 10⁹/L correlated significantly with both early death and DS.

t(15; 17) associated with primary myelofibrosis: a case report of an unusual clinical presentation and diagnostic dilemma

Background

primary myelofibrosis (PMF) is a myeloproliferative neoplasm which is associated with clonal molecular and cytogenetic abnormalities (CA) and varied clinical manifestations. While various CA have been previously described, t(15; 17) has not been reported in association with this condition.

Case presentation

A 69-year-old male presented with constitutional symptoms, cytopenias and bone marrow biopsy revealed immature blasts with fibrosis. Cytogenetic analysis showed a t(15;17) which initially suggested a diagnosis of acute promyelocytic leukemia (APL). However, flourescence in situ hybridization (FISH) and reverse transcriptase polymerase chain reaction (RT-PCR) studies were negative for transcripts promyelocytic leukemia (PML) gene and retinoic acid receptor alpha (RARA) or PML-RARA fusion. Along with these results, a second review of bone marrow histology, flowcytometry and the detection of a calreticulin gene (CALR) mutation helped with the correct diagnosis of PMF. Patient was then treated with ruxolitinib, a JAK (Janus kinase) 1 and 2 inhibitor, and eventually proceeded to receive a matched unrelated reduced intensity conditioning (RIC) allogeneic stem cell transplantation (ASCT) and has been doing well at the 6-month follow up.

Conclusions

Our case highlights two points, that the t(15;17) is diagnostic of Acute Promyelocytic Leukemia (APL) in most cases, there are exceptions and it can be associated with other malignancies without causing any APL like features, as noted in this case. Also, that t(15; 17) by itself is never sufficient to diagnose APL without confirmation by other methods and relying solely on cytogenetics without timely confirmatory tests can lead to risks of delay in diagnosis and appropriate management.

Cancer Cell Lines Are Useful Model Systems for Medical Research

Cell lines are in vitro model systems that are widely used in different fields of medical research, especially basic cancer research and drug discovery. Their usefulness is primarily linked to their ability to provide an indefinite source of biological material for experimental purposes. Under the right conditions and with appropriate controls, authenticated cancer cell lines retain most of the genetic properties of the cancer of origin. During the last few years, comparing genomic data of most cancer cell lines has corroborated this statement and those that were observed studying the tumoral tissue equivalents included in the The Cancer Genome Atlas (TCGA) database. We are at the disposal of comprehensive open access cell line datasets describing their molecular and cellular alterations at an unprecedented level of accuracy. This aspect, in association with the possibility of setting up accurate culture conditions that mimic the in vivo microenvironment (e.g., three-dimensional (3D) coculture), has strengthened the importance of cancer cell lines for continuing to sustain medical research fields. However, it is important to consider that the appropriate use of cell lines needs to follow established guidelines for guaranteed data reproducibility and quality, and to prevent the occurrence of detrimental events (i.e., those that are linked to cross-contamination and mycoplasma contamination).

All-trans retinoic acid protects mesenchymal stem cells from immune thrombocytopenia by regulating the complement-interleukin-1β loop

Enhanced peripheral complement activation has long been considered as one of the major pathogenic elements of immune thrombocytopenia. A dysfunctional bone marrow microenvironment, especially with regards to mesenchymal stem cells, has been observed in patients with immune thrombocytopenia. However, the potential role of the complement system in the dysfunctional bone marrow microenvironment remains poorly understood. In this study, bone marrow samples from patients with immune thrombocytopenia were divided into two groups based on whether or not complement components were deposited on the surfaces of their mesenchymal stem cells. The mesenchymal cells from the group with complement deposition were less numerous, dysfunctional, had a reduced capacity to proliferate, and showed increased apoptosis as well as abnormal secretion of interleukin-1β and C-X-C motif chemokine ligand 12. In vitro treatment with all-trans retinoic acid increased the number and improved the function of the complement-positive bone marrow mesenchymal stem cells by upregulating DNA hypermethylation of the interleukin-1β promoter. In vivo studies showed that all-trans retinoic acid could rescue the impaired mesenchymal stem cells to support the thrombopoietic niche in both patients with immune thrombocytopenia and a murine model of this disease. Taken together, these results indicate that impairment of mesenchymal stem cells, mediated by the complement-interleukin-1β loop, plays a role in the pathogenesis of immune thrombocytopenia. All-trans retinoic acid represents a promising therapeutic approach in patients with immune thrombocytopenia through its effect of repairing mesenchymal stem cell impairment.

MRD in AML: The Role of New Techniques

In the context of precision medicine, assessment of minimal residual disease (MRD) has been used in acute myeloid leukemia (AML) to direct individual treatment programs, including allogeneic stem cell transplantation in patients at high-risk of relapse. One of the limits of this approach has been in the past the paucity of AML markers suitable for MRD assessment. Recently, the number of biomarkers has increased, due to the identification of highly specific leukemia-associated immunophenotypes by multicolor flow-cytometry, and of rare mutated gene sequences by digital droplet PCR, or next-generation sequencing (NGS). In addition, NGS allowed unraveling of clonal heterogeneity, present in AML at initial diagnosis or developing during treatment, which influences reliability of specific biomarkers, that may be unstable during the disease course. The technological advances have increased the application of MRD-based strategies to a significantly higher number of AML patients, and the information deriving from MRD assessment has been used to design individual post-remission protocols and pre-emptive treatments in patients with sub-clinical relapse. This led to the definition of MRD-negative complete remission as outcome definition in the recently published European Leukemianet MRD guidelines. In this review, we summarized the principles of modern technologies and their clinical applications for MRD detection in AML patients, according to the specific leukemic markers.

ZYH005, a novel DNA intercalator, overcomes all-trans retinoic acid resistance in acute promyelocytic leukemia

Despite All-trans retinoic acid (ATRA) has transformed acute promyelocytic leukemia (APL) from the most fatal to the most curable hematological cancer, there remains a clinical challenge that many high-risk APL patients who fail to achieve a complete molecular remission or relapse and become resistant to ATRA. Herein, we report that 5-(4-methoxyphenethyl)-[1, 3] dioxolo [4, 5-j] phenanthridin-6(5H)-one (ZYH005) exhibits specific anticancer effects on APL and ATRA-resistant APL in vitro and vivo, while shows negligible cytotoxic effect on non-cancerous cell lines and peripheral blood mononuclear cells from healthy donors. Using single-molecule magnetic tweezers and molecule docking, we demonstrate that ZYH005 is a DNA intercalator. Further mechanistic studies show that ZYH005 triggers DNA damage, and caspase-dependent degradation of the PML-RARa fusion protein. As a result, APL and ATRA-resistant APL cells underwent apoptosis upon ZYH005 treatment and this apoptosis-inducing effect is even stronger than that of arsenic trioxide and anticancer agents including 5-fluorouracil, cisplatin and doxorubicin. Moreover, ZYH005 represses leukemia development in vivo and prolongs the survival of both APL and ATRA-resistant APL mice. To our knowledge, ZYH005 is the first synthetic phenanthridinone derivative, which functions as a DNA intercalator and can serve as a potential candidate drug for APL, particularly for ATRA-resistant APL.

A case of acute promyelocytic leukemia variant with derivative chromosome 3 der(3)t(3;8) associated with 8q partial gain

Background

Acute promyelocytic leukemia (APL) is characterized by fusion of PML/RARα genes as a result of t(15;17)(q24;q21). APL is now one of the curable hematological malignancies thanks to molecularly targeted therapies based on all-trans retinoic acid (ATRA) and arsenic trioxide (ATX). Extramedullary (EM) relapse is a rare event in APL, ear involvement being even more infrequent, with only six cases so far described. About 30–35% of patients with newly diagnosed APL have additional cytogenetics abnormalities, whose prognostic significance is still controversial. The most common additional aberration is trisomy 8 or partial gain 8q.

Case presentation

We describe here a novel unbalanced translocation der(3)t(3;8)(q29;q23.3-q24.3) associated with 8q partial gain in a 41 year-old man affected by APL in molecular remission after first line treatment, who had a responsive EM relapse in the auditory canal.

Conclusions

EM relapse is a rare event in APL and ear involvement is even more infrequent. To our knowledge, this is the first reported case of APL with a new der(3)t(3;8)(q29;q23.3-q24.3) and 8q partial gain associated with t(15;17)(q24;q21). Despite the recurrence of the disease at EM level, the clinical outcome of this patients was favorable.

Retinoic acid and arsenic trioxide induce lasting differentiation and demethylation of target genes in APL cells

Acute promyelocytic leukemia (APL) is characterized by arrested differentiation of promyelocytes. Patients treated with all-trans retinoic acid (ATRA) alone experience relapse, while patients treated with ATRA and arsenic trioxide (ATO) are often relapse-free. This suggests sustained changes have been elicited by the combination therapy. To understand the lasting effects of the combination therapy, we compared the effects of ATRA and ATO on NB4 and ATRA-resistant NB4-MR2 APL cells during treatment versus post treatment termination. After treatment termination, NB4 cells treated with ATRA or ATO reverted to non-differentiated cells, while combination-treated cells remained terminally differentiated. This effect was diminished in NB4-MR2 cells. This suggests combination treatment induced more permanent changes. Combination treatment induced higher expression of target genes (e.g., transglutaminase 2 and retinoic acid receptor beta), which in NB4 cells was sustained post treatment termination. To determine whether sustained epigenetic changes were responsible, we quantified the enrichment of histone modifications by chromatin immunoprecipitation, and CpG methylation by bisulfite-pyrosequencing. While ATRA and combination treatment induced similar histone acetylation enrichment, combination treatment induced greater demethylation of target genes, which was sustained. Therefore, sustained demethylation of target genes by ATRA and ATO combination treatment is associated with lasting differentiation and gene expression changes.

Early treatment of acute promyelocytic leukaemia is accurately guided by the PML protein localisation pattern: real-life experience from a tertiary New Zealand centre

Current guidelines recommend that a rapid test be used to assist diagnosis of acute promyelocytic leukaemia (APL), but the choice of an assay is discretionary. PML immunofluorescence (PML IF) identifies the microparticulate pattern of the PML protein localisation, highly specific for APL. The aim of this study was to evaluate clinical utility of PML IF in a real-life setting based on a retrospective records review for all patients who had PML IF performed in our centre between 2000 and 2017. Final analysis included 151 patients, 70 of whom had APL. PML IF was reported on average 3 days faster than cytogenetics. Compared with genetic results, PML IF showed sensitivity of 96% and specificity of 100%. PML IF accurately predicted APL in four APL cases with cryptic karyotype/FISH and excluded APL in 98% cases tested based on the suspicious immunophenotype alone, 21/28 of whom had mutated NPM1. Results of PML IF influenced decision to start ATRA in 25 (36%) APL patients and led to its termination in six non-APL patients. In conclusion, PML IF is a fast and reliable test that facilitates accurate treatment decisions when APL is suspected. This performance of PML IF remains hard to match in a real-life setting.

An Unusual Coexistence of Primary Central Nervous System Non-Hodgkin's Lymphoma and Acute Promyelocytic Leukemia

Acute promyelocytic leukemia and primary central nervous system lymphoma are uncommon hematological malignancies. The co-occurrence of acute myeloid leukemia with various lymphoproliferative diseases is an extremely rare condition, especially in the absence of previous chemotherapy or radiotherapy. Herein, we provide a comprehensive characterization of a patient with concomitant diagnosis of extranodal high-grade non-Hodgkin B-cell neoplasm confined to the central nervous system and acute promyelocytic leukemia. We describe the efficacy and feasibility of the consecutive use of all-trans retinoic acid and arsenic trioxide-containing regimen for the treatment of promyelocytic leukemia and high-dose methotrexate plus cytarabine to treat lymphoproliferative involvement of the central nervous system.

Arsenic trioxide reverses the chemoresistance in hepatocellular carcinoma: a targeted intervention of 14-3-3η/NF-κB feedback loop

Background

Multi-drug resistance (MDR) is one of the main obstacles for treatment of advanced/recurrent hepatocellular carcinoma (HCC). We have previously identified arsenic trioxide (ATO) as an effective metastasis/angiogenesis inhibitor in HCC. Here, we further found that MDR-HCC cells were more sensitive to ATO.

Methods

The MDR-HCC cells were used as experimental models. Biological functions were investigated using cell transfection, polymerase chain reaction, western blot, southwestern blot, immunostaining, immunoprecipitation plus atomic fluorescence spectrometry, and so on.

Results

The MDR-HCC cells underwent high oxidative stress condition, and employed adaptive mechanisms for them to survive; while ATO abolished such mechanisms via targeting the 14–3-3η/nuclear factor kappa B (NF-κB) feedback Loop. Briefly, in MDR cells, the increase of ROS activated NF-κB signaling, which transcriptionally activated 14–3-3η. Meanwhile, the activation of NF-κB can be constitutively maintained by 14–3-3η. As a NF-κB inhibitor, ATO transcriptionally inhibited the 14–3-3η mRNA level. Meanwhile, ATO was also validated to directly bind to 14–3-3η, enhancing the degradation of 14–3-3η protein in an ubiquitination-dependent manner. Knockdown of 14–3-3η reduced the ATO-induced reversal extents of drug resistance in MDR cells.

Conclusion

14–3-3η/NF-κB feedback loop plays an important role in maintaining the MDR phenotype in HCC. Moreover, via targeting such feedback loop, ATO could be considered as a potential molecular targeted agent for the treatment of HCC.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-1005-y) contains supplementary material, which is available to authorized users.

A Review and Assessment of Drug-Induced Thrombocytosis

OBJECTIVES

The purpose of this article is to review the current literature on drug-induced thrombocytosis with the goal of critically assessing causality and providing a comprehensive review of the topic. Thrombopoietic growth factors, such as thrombopoietin-receptor agonists (romiplostim and eltrombopag) and erythropoietin are not included in our review.

DATA SOURCES

The literature search included published articles limited to the English language and humans in MEDLINE, EMBASE, and Web of Science databases. MEDLINE/PubMed (1966 to September 2018) was searched using the MeSH terms thrombocytosis/chemically-induced and thrombocytosis/etiology. EMBASE (1980 to September 2018) was searched using the EMTAGS thrombocytosis/side effect. Web of Science (1970 to September 2018) was searched using the search term thrombocytosis. References of all relevant articles were reviewed for additional citations and information.

STUDY SELECTION AND DATA EXTRACTION

Review articles, clinical trials, background data, case series, and case reports of drug-induced thrombocytosis were collected, and case reports were assessed for causality using a modified Naranjo nomogram.

DATA SYNTHESIS

Drug-induced thrombocytosis, a form of reactive thrombocytosis cannot be easily differentiated from more common etiologies of reactive thrombocytosis. In all, 43 case reports of drug-induced thrombocytosis from a wide variety of drugs and drug classes were reviewed using a modified Naranjo probability scale that included criteria specific for thrombocytosis.

CONCLUSIONS

Drug-induced thrombocytosis is a relatively rare adverse drug reaction. The strongest evidence of causality supports low-molecular-weight heparins and neonatal drug withdrawal. Weaker evidence exists for all-trans retinoic acid, antibiotics, clozapine, epinephrine, gemcitabine, and vinca alkaloids.

Multicenter randomized trial of arsenic trioxide and Realgar-Indigo naturalis formula in pediatric patients with acute promyelocytic leukemia: Interim results of the SCCLG-APL clinical study

Intravenous arsenic trioxide (ATO) has been adopted as the first‐line treatment for acute promyelocytic leukemia (APL). Another arsenic compound named the Realgar‐Indigo naturalis formula (RIF), an oral traditional Chinese medicine containing As₄S₄, has been shown to be highly effective in treating adult APL. In the treatment of pediatric APL, the safety and efficacy of RIF remains to be confirmed. This randomized, multicenter, and noninferiority trial was conducted to determine whether intravenous ATO can be substituted by oral RIF in the treatment of pediatric APL. From September 2011 to January 2017, among 92 patients who were 16 years old or younger with newly diagnosed PML‐RARa positive APL, 82 met eligible criteria and were randomly assigned to ATO (n = 42) or RIF (n = 40) group. The remaining 10 patients did not fulfilled eligible criteria because five did not accept randomization, four died and one had hemiplegia prior to arsenic randomization due to intracranial hemorrhage or cerebral thrombosis. Induction and consolidation treatment contained ATO or RIF, all‐trans‐retinoic acid and low intensity chemotherapy. End points included event‐free survival (EFS), adverse events and hospital days. After a median 3‐year follow‐up, the estimated 5‐year EFS was 100% in both groups, and adverse events were mild. However, patients in the RIF group had significantly less hospital stay than those in the ATO group. This interim analysis shows that oral RIF is as effective and safe as intravenous ATO for the treatment of pediatric APL, with the advantage of reducing hospital stay. Final trial analysis will reveal mature outcome data.

Clinical management of Australian adolescents and young adults with acute lymphoblastic and myeloid leukemias: A national population-based study

BACKGROUND

While several studies have examined the treatment of adolescents and young adults (AYAs) with acute lymphoblastic leukemia (ALL), studies of acute myeloid leukemia (AML) are rare. Using national data for Australia, we describe (i) the number and type of treatment centers caring for AYAs, (ii) induction/first-line treatments, and (iii) survival outcomes.

PROCEDURE

National population-based study assessing treatment of 15- to 24-year-olds diagnosed with ALL or AML between 2007 and 2012. Treatment details were abstracted from hospital medical records. Treatment centers were classified as pediatric or adult (adult AYA-focused or other adult; and by AYA volume [high/low]). Cox proportional hazard regression analyses examined associations between treatment and overall, event-free, and relapse-free survival outcomes.

RESULTS

Forty-seven hospitals delivered induction therapy to 351 patients (181 ALL and 170 AML), with 74 (21%) treated at pediatric centers; 70% of hospitals treated less than two AYA leukemia patients per year. Regardless of treatment center, 82% of ALL patients were on pediatric protocols. For AML, pediatric protocols were not used in adult centers, with adult centers using a non-COG 7+3-type induction protocol (51%, where COG is Cooperative Oncology Group) or an ICE-type protocol (39%, where ICE is idarubicin, cytarabine, etoposide). Exploratory analyses suggested that for both ALL and AML, AYAs selected for adult protocols have worse overall, event-free, and relapse-free survival outcomes.

CONCLUSIONS

Pediatric protocols were commonly used for ALL patients regardless of where they are treated, indicating rapid assimilation of recent evidence by Australian hematologists. For AML, pediatric protocols were only used at pediatric centers. Further investigation is warranted to determine the optimal treatment approach for AYA AML patients.

[Efficacy of combination of ATRA, ATO and anthracyclines induction therapy in patients with acute promyelocytic leukemia]

Objective: To explore the efficacies of regimens of three-drug induction therapy (ATRA+ATO+anthracyclines) versus two-drug induction therapy (ATRA+ATO) in patients with acute promyelocytic leukemia (APL). Methods: Of 184 patients diagnosed with APL from January 2009 to March 2016, 58 patients underwent three-drug induction therapy, while the rest were treated with two-drug induction therapy. Three-drug induction therapy was of ATRA (20 mg·m(-2)·d(-1), d(1-28)) + ATO (0.16 mg·kg(-1)·d(-1), d(1-28)) + Idarubicin (8 mg·m(-2)·d(-1), d(3-5)) /daunorubicin (40 mg·m(-2)·d(-1), d(3-5)) , while two-drug induction therapy ATRA+ATO with the same doses and methods as above. Of 184 cases, 69 cases accompanied with WBC counts>10×10(9)/L, 115 cases with WBC counts≤10×10(9)/L at onset. Results: ①Short-term efficacy: After one cycle induction therapy, the rates of hematologic remission, genetic remission, molecular remission and induced differentiation syndrome (DS) in three-drug regimen group were 98.3%, 87.9%, 72.4% and 0 respectively, while those in two-drug regimen group were 87.3%, 65.9%, 51.6% and 12.7% respectively. In patients with WBC >10×10(9)/L, DS rate and early mortality in three-drug regimen group were lower than in two-drug regimen group (0 vs 15.6%, 4.2% vs 15.6%, respectively). In patients with WBC≤10×10(9)/L, DS rate in three-drug regimen group was also lower than in two-drug regimen group (0 vs 12.3%) , but there were no statistical differences in terms of relapse and early mortality. ② Long-term efficacy: The relapse rate, overall survival (OS) and disease free survival (DFS) in three-drug regimen group were 0, 98.5%, 96.6% respectively, while those in two-drug regimen group were 8.6%, 86.5% and 84.1% respectively; the advantages of three-drug over two-drug regimen, especially in cases of WBC >10×10(9)/L were observed. ③ Side effects: the incidences of gastrointestinal reaction, liver dysfunction, myocardial damage and headache in three-drug regimen group hardly increased. Conclusion: The efficacies of three-drug induction therapy were superior to two-drug one.

Antitumor effects of arsenic disulfide on the viability, migratory ability, apoptosis and autophagy of breast cancer cells

In the present study, the antitumor effects of arsenic disulfide (As₂S₂) on the proliferative, survival and migratory ability of human breast cancer MCF-7 and MDA-MB-231 cells were investigated, and its potential underlying molecular mechanisms with an emphasis on cell cycle arrest, apoptosis induction, autophagy induction and reactive oxygen species (ROS) generation were determined. The results indicated that As₂S₂ significantly inhibited the viability, survival and migration of breast cancer cells in a dose-dependent manner. In addition, it was identified that As₂S₂ induced cell cycle arrest primarily at G₂/M phase in the two breast cancer cell lines by regulating the expression of associated proteins, including cyclin B1 and cell division cycle protein 2. In addition to cell cycle arrest, As₂S₂ also triggered the induction of apoptosis in cells by activating the expression of pro-apoptotic proteins, including caspase-7 and −8, as well as increasing the B-cell lymphoma 2 (Bcl-2)-associated X protein/Bcl-2 ratio, while decreasing the protein expression of anti-apoptotic B-cell lymphoma extra-large. In addition, As₂S₂ stimulated the accumulation of microtubule-associated protein 1A/1B-light chain 3 (LC3)-II and increased the LC3-II/LC3-I ratio, indicating the occurrence of autophagy. As₂S₂ treatment also inhibited the protein expression of matrix metalloproteinase-9 (MMP-9), but increased the intracellular accumulation of ROS in the two breast cancer cell lines, which may assist in alleviating metastasis and attenuating the progression of breast cancer. Taken together, the results of the present study suggest that As₂S₂ inhibits the progression of human breast cancer cells through the regulation of cell cycle arrest, intrinsic and extrinsic apoptosis, autophagy, MMP-9 signaling and ROS generation.

Development of acute promyelocytic leukemia in a patient with tetraplegia while in inpatient rehabilitation: A case report

STUDY DESIGN

a single case report.

OBJECTIVES

To report a case of a patient with tetraplegia who developed acute promyelocytic leukemia (APL) while in inpatient rehabilitation after 10.5 months.

SETTING

A VA Medical Center Spinal Cord Injury Service and Disorders Unit Case Report: A 47 year-old male with a stage IV sacral pressure ulcer and C4 AIS A complete tetraplegia secondary to a motor vehicle collision, developed fever, thrombocytopenia, and anemia 20 months after his injury while in inpatient rehabilitation and was found to have APL, confirmed following bone marrow biopsy.

CONCLUSION

There is a wide differential for fever after a spinal cord injury. In this case report, the source of fever was APL. It is important as healthcare providers to not overlook fevers when otherwise common causes do not fit the clinical picture. Additionally, there has been no association found between traumatic spinal cord injury and the development of acute leukemia, however this is the first case report. Therefore, it is important to continue investigating to determine if an association exists.

Basophil-lineage commitment in acute promyelocytic leukemia predicts for severe bleeding after starting therapy

Severe hemorrhagic events occur in a significant fraction of acute promyelocytic leukemia patients, either at presentation and/or early after starting therapy, leading to treatment failure and early deaths. However, identification of independent predictors for high-risk of severe bleeding at diagnosis, remains a challenge. Here, we investigated the immunophenotype of bone marrow leukemic cells from 109 newly diagnosed acute promyelocytic leukemia patients, particularly focusing on the identification of basophil-related features, and their potential association with severe bleeding episodes and patient overall survival.From all phenotypes investigated on leukemic cells, expression of the CD203c and/or CD22 basophil-associated markers showed the strongest association with the occurrence and severity of bleeding (p ≤ 0.007); moreover, aberrant expression of CD7, coexpression of CD34⁺/CD7⁺ and lack of CD71 was also more frequently found among patients with (mild and severe) bleeding at baseline and/or after starting treatment (p ≤ 0.009). Multivariate analysis showed that CD203c expression (hazard ratio: 26.4; p = 0.003) and older age (hazard ratio: 5.4; p = 0.03) were the best independent predictors for cumulative incidence of severe bleeding after starting therapy. In addition, CD203c expression on leukemic cells (hazard ratio: 4.4; p = 0.01), low fibrinogen levels (hazard ratio: 8.8; p = 0.001), older age (hazard ratio: 9.0; p = 0.002), and high leukocyte count (hazard ratio: 5.6; p = 0.02) were the most informative independent predictors for overall survival.In summary, our results show that the presence of basophil-associated phenotypic characteristics on leukemic cells from acute promyelocytic leukemia patients at diagnosis is a powerful independent predictor for severe bleeding and overall survival, which might contribute in the future to (early) risk-adapted therapy decisions.

Acute Promyelocytic Leukemia in Children: A Single Centre Experience from Turkey

Background and objectives

Acute promyelocytic leukemia (APL), is a distinct subtype of acute myeloid leukemia (AML) characterized by a tendency to hemorrhage and excellent response to all-trans retinoic acid (ATRA). In this retrospective study, we aimed to determine the incidence, clinical symptoms, toxicities, and outcome of children with APL in our center.

Methods

We retrospectively reviewed the medical records of children (age < 18 years) diagnosed with APL in our pediatric hematology department between January 2006-December 2016.

Results

Pediatric APL represents 20.5% of AML cases in this cohort. Most of the cases presented as classical M3, albeit hypogranular variant was described in 12% of the cohort. Patients with hypogranular variant APL were differed from classical APL by co-expression of CD2 and CD34. About ¾ of APL patients had hemorrhagic findings at admission or the induction treatment. Severe bleeding manifested as intracranial hemorrhage was present in three patients and intracranial arterial thrombosis was present in one. Six patients showed side effects of ATRA such as pseudotumor cerebri, differentiation syndrome resulting in dilated cardiomyopathy, and pulmonary infiltrates. Five-year overall survival (OS) and early death rate were found to be 82.5% and 12% respectively.

Conclusions

A high frequency (20.5%) of APL was noted among children with AML in this single-center study. The overall mortality rate was 17.5%. Since the induction death rate was 12% and life-threatening bleeding was the primary problem, awareness and urgent treatment are critical factors to reduce early losses.

Downregulation of ROS1 enhances the therapeutic efficacy of arsenic trioxide in acute myeloid leukemia cell lines

The present study investigated the function of ROS proto-oncogene 1 receptor tyrosine kinase (ROS1) in regulating the migration and proliferation of acute myeloid leukemia (AML) cells through Wnt/β-catenin signaling, and in arsenic trioxide (ATO) treatment. The migration and proliferation of multiple ROS1-silenced leukemic cell lines was assessed, and the expression levels of proteins associated with Wnt/β-catenin signaling were determined using western blot analysis. Compared with the AML control cells, ROS1-knockdown cells exhibited increased migration and proliferation, and the significant downregulation of β-catenin expression. Additionally, ROS1 knockdown sensitized AML cells to the effects of chemotherapeutic ATO. The results of the present study demonstrated that, in leukemic cell lines, ROS1 counteracted the effects of ATO on migration and proliferation, suggesting that ROS1 may be a potential therapeutic target in patients with AML undergoing ATO treatment. The results of the present study provided novel insight into the function of ATO and ROS1 in regulating AML progression.

Secondary clonal hematologic neoplasia following successful therapy for acute promyelocytic leukemia (APL): A report of two cases and review of the literature

Although rare, secondary clonal hematologic neoplasia may occur after successful therapy for acute promyelocytic leukemia (APL). These secondary clonal events may be considered therapy-related, but may also be due to an underlying background of clonal hematopoiesis from which both malignancies may develop. In this manuscript, we describe two patients with secondary clones after APL therapy characterized in one patient by deletion of chromosome 11q23 and, in the other, by monosomy of chromosome 7, and also provide a review of all secondary clonal disorders described after APL therapy. We suggest that since most reports identify karyotypic abnormalities not typically associated with chemotherapy, there may be another mechanism underlying secondary clonal development after complete response to initial APL therapy.

Arsenic disulfide‑induced apoptosis and its potential mechanism in two‑ and three‑dimensionally cultured human breast cancer MCF‑7 cells

In China, arsenic disulfide (As2S2) has been used for the treatment of hematological malignancies. The present study aimed to evaluate the effects of As2S2 on the human breast cancer MCF‑7 cell line cultured in both two‑dimensional (2D) monolayers and three‑dimensional (3D) spheroids to explore its therapeutic potential in breast cancer treatment. Cellular viability and the induction of apoptosis were examined with a cell counting kit‑8 (CCK‑8) assay and flow cytometric analysis, respectively. Alterations in the expression levels of apoptosis‑associated proteins, including Bcl‑2‑associated X protein (Bax), B‑cell lymphoma 2 (Bcl‑2), p53, and caspase‑7, as well as the cell survival‑associated proteins, phosphatidylinositol 3‑kinase (PI3K), Akt, and mammalian target of rapamycin (mTOR), were assessed by western blotting. Although a dose‑dependent reduction in cell viability, which occurred in association with the induction of apoptosis triggered by the addition of 2‑24 µM As2S2, was observed in both 2D‑ and 3D‑culture systems, 3D spheroids were less sensitive to the cytotoxic effect of As2S2 compared with the 2D cultured cells. A significant increase in the expression levels of Bax, p53, and caspase‑7 was observed in treated 2D‑cultured cells, whereas a similar increase in the expression levels of Bax was only confirmed in treated 3D spheroids, although there was a trend towards the increased expression of p53 and caspase‑7 in the 3D spheroids. These results suggested that these molecules are closely associated with As2S2‑mediated cytotoxicity in the two culture systems, and further suggested that the difference in the sensitivity to As2S2 between 2D monolayers and 3D spheroids may be attributed to the differential alterations in the expression levels of proteins associated with cell mortality. Significant downregulation of the expression levels of Bcl‑2, PI3K, Akt and mTOR was observed in the two culture systems. Taken together, the results of the present study demonstrated that As2S2 inhibits cell viability and induces apoptosis in both 2D‑ and 3D‑ cultured MCF‑7 cells, which may be associated with activation of the pro‑apoptotic pathway and the inhibition of pro‑survival signaling. These results have provided novel insights into clinical applications of As2S2 in the treatment of patients with breast cancer.

Role of cytarabine in paediatric acute promyelocytic leukemia treated with the combination of all-trans retinoic acid and arsenic trioxide: a randomized controlled trial

Background

The combination of all-trans-retinoic acid (ATRA) and arsenic trioxide (ATO) has been suggested to be safe and effective for adult acute promyelocytic leukaemia (APL). As of 2010, the role of cytarabine (Ara-C) in APL was controversial. The aim of this study was to test the efficacy and safety of ATRA and ATO in paediatric APL patients. Also, we assessed whether Ara-C could be omitted in ATO and ATRA- based trials in children.

Methods

We performed a randomized controlled trial in paediatric APL patients (≤14 years of age) in our hospital from May 2010 to December 2016. All of the patients were assigned to receive ATRA plus ATO for induction followed by one course of idarubicin (IDA) and ATO (28 days). The patients were then randomly assigned to receive two courses of daunorubicin (DNR, no- Ara-C group) or DNR + Ara-C (Ara-C group). All of the patients were followed with maintenance therapy with oral ATRA, 6-mercaptopurine, and methotrexate for 1.5 years.

Results

Among the 66 patients, 43 were male and 23 were female. All of the patients achieved complete remission (CR) with the exception of one who gave up the treatment. During induction therapy, all toxicity events were reversed after appropriate management. Thirty patients in the Ara-C group underwent 57 courses of treatment, and 35 patients in the no-Ara-C group underwent 73 courses of treatment. No significant differences in age, genders, white blood cell counts, haemoglobin levels, and platelet counts were found between the Ara-C and no-Ara-c groups. Greater myelosuppression and sepsis were observed in the Ara-C group during the consolidation courses. No patient died at consolidation, and only one patient relapsed. No differences were found in event-free survival, disease-free survival and overall survival between the two groups. Additionally, our analysis of the arsenic levels in the plasma, urine, hair and nails of the patients indicated that no significant accumulation of arsenic occurred after ATO was discontinued for 12 months.

Conclusions

Overall, ATO and ATRA are safe and effective for paediatric APL patients and Ara-C could be omitted when ATO is used for two courses.

Trial registration

ClinicalTrials.gov (NCT01191541, retrospectively registered on 18 August 2010).

SCD5 restored expression favors differentiation and epithelial-mesenchymal reversion in advanced melanoma

Our previous data supported a role for the Stearoyl-CoA desaturase (SCD5) in protection against malignancy, whereby it appears to functionally modify tumor stroma impairing tumor spread. SCD5 is significantly expressed in primary melanoma, but becomes barely detectable at tumor advanced stages. Looking for the regulatory mechanisms underlying SCD5 reduced expression during melanoma progression, we demonstrated a significantly lower stability of SCD5 protein as well as the direct targeting of SCD5 mRNA by the oncogenic miR-221&222 in metastatic cell lines. Moreover, our results indicated the existence of a negative feedback loop between SCD5 and miR-221&222, in good agreement with their opposite functions. Also, we showed how SCD5 re-expression and the direct supplementation of its main product oleic acid (OA) can drive advanced melanoma cell lines toward differentiation and reversion of the epithelial-mesenchymal (EMT)-like process, eventually inducing a less malignant phenotype. Indeed, SCD5 re-established the sensitivity to all-trans retinoic acid in A375M metastatic melanoma, associated with increased levels of Tyrosinase, melanin production and reduced proliferation. As evidenced by the correct modulation of some key transcription factors, SCD5 managed by favoring a partial mesenchymal-to-epithelial (MET) transition in in vitro studies. Interestingly, a more complete MET, including E-cadherin re-expression correctly localized at cell membranes, was obtained in in vivo xenograft models, thus indicating the requirement of direct contacts between tumor cells and the surrounding microenvironment as well as the presence of some essential factors for SCD5 complete function.

Aberrant expression of enzymes regulating m6A mRNA methylation: implication in cancer

N⁶-methyladenosine (m⁶A) is an essential RNA modification that regulates key cellular processes, including stem cell renewal, cellular differentiation, and response to DNA damage. Unsurprisingly, aberrant m⁶A methylation has been implicated in the development and maintenance of diverse human cancers. Altered m⁶A levels affect RNA processing, mRNA degradation, and translation of mRNAs into proteins, thereby disrupting gene expression regulation and promoting tumorigenesis. Recent studies have reported that the abnormal expression of m⁶A regulatory enzymes affects m⁶A abundance and consequently dysregulates the expression of tumor suppressor genes and oncogenes, including MYC, SOCS2, ADAM19, and PTEN. In this review, we discuss the specific roles of m⁶A "writers", "erasers", and "readers" in normal physiology and how their altered expression promotes tumorigenesis. We also describe the potential of exploiting the aberrant expression of these enzymes for cancer diagnosis, prognosis, and the development of novel therapies.

Preclinical Antileukemia Activity of Tramesan: A Newly Identified Bioactive Fungal Metabolite

Despite improvements that occurred in the last decades in the acute myeloid leukemia (AML) treatment, clinical results are still unsatisfactory. More effective therapies are required, and innovative approaches are ongoing, including the discovery of novel antileukemia natural compounds. Several studies have described the activity of extracts from mushrooms which produce compounds that exhibited immunological and antitumor activities. The latter has been demonstrated to be promoted in vitro by mushroom polysaccharides via induction of apoptosis. However, the antileukemia activity of these compounds on primary cells is still not reported. In the present study, we examined the in vitro effects of Tramesan (TR), a bioactive compound extracted from Trametes versicolor, on leukemic cell lines and primary cells. Our results demonstrated that TR induced a marked growth inhibition of leukemic cell lines and primary cells from AML patients. The antiproliferative effects of TR were associated in primary AML cells with a significant increase of apoptosis. No significant cytotoxic effects were observed in normal peripheral blood mononuclear cells (MNC) from healthy donors. Our data demonstrated a cytotoxic activity of TR on leukemia cells prompting further translational applications. Ongoing studies are elucidating the molecular mechanisms underlying its antileukemic activity.

Nucleostemin silencing induces differentiation and potentiates all-trans-retinoic acid effects in human acute promyelocytic leukemia NB4 cells via autophagy

Here, we report that targeting Nucleostemin (NS), a recently discovered stem cells-enriched gene, by a specific small interference RNA (siNS), decreases the rate of proliferation of acute promyelocytic leukemia (APL) NB4 cells and induces differentiation and autophagy. In addition, NS silencing promotes the effects of all-trans-retinoic acid (ATRA)-based differentiation therapy in NB4 cells. Autophagy inhibitors 3-methyladenine and bafilomycin block the effect of NS targeting on differentiation, indicating a new functional link between NS and autophagy as an important regulator of differentiation in NB4 cells. The capability of NS in modulating autophagy and differentiation, alone or in combination with ATRA, may help to broaden the range of treatment options available to treat leukemia.

Arsenic trioxide exposure impairs testicular morphology in adult male mice and consequent fetus viability

The acute promyelocytic leukemia (APL) is a rare disease, affecting 0.1/100,000 individuals globally. Despite significant advances in APL therapy, some patients still experience relapsed disease. Currently, arsenic trioxide (As₂O₃) was found to be effective in relapsed APL treatment and considered as standard treatment for these cases. However, it has been shown that exposure to As₂O₃ may exert adverse effects on the male reproductive system since this substance might also induce apoptosis of other important cell types including stem cells. Studies demonstrated that treatment with this metallic substance decreased plasma levels of testosterone and interfered with sperm parameters such as concentration, motility, and viability. In addition, As₂O₃ was found to produce significant damage to spermatocytes, which may be associated with testicular toxicity and consequent inhibition of spermatogenesis. The aim of this study was to determine sub-chronic treatment effects of As₂O₃ on sperm and testicular morphology, androgen receptor (AR) immunoreactivity in testes and epididymis, in addition to evaluation of fertility parameters in adult male mice. Thirty adult Swiss mice were divided into three experimental groups: control; received distilled water (vehicle) while treated received 0.3 or 3 mg/kg/day As₂O₃ subcutaneously, for 5 days per week, followed by 2 days of interruption, for 5 weeks. Results showed that As₂O₃ (1) decreased spermatozoa number, (2) produced seminiferous epithelium degeneration and exfoliation of germ cells tubule lumen (3) altered nucleus/cytoplasm proportion of Leydig cells and (4) reduced AR immunoreactivity in both Leydig and epithelial epididymal cells. Further, fetal viability tests demonstrated an increase in post-implantation loss in females that were mated with As₂O₃-treated males. Data indicate that As₂O₃ exposure altered the spermatogenic process and subsequently fetal viability.

Practical Implications of the 2016 Revision of the World Health Organization Classification of Lymphoid and Myeloid Neoplasms and Acute Leukemia

A major revision of the WHO classification of lymphoid and myeloid neoplasms and acute leukemia was released in 2016. A key motivation for this update was to include new information available since the 2008 version with clinical relevance for the diagnosis, prognosis, and therapy of patients. With > 100 entities described, it is important for the clinician to understand features that may be important in daily practice, whereas researchers need to incorporate the new classification scheme into study development and analysis. In this review, we highlight the key aspects of the 2016 update with particular importance to routine patient care and clinical trial design.

LRRC25 plays a key role in all-trans retinoic acid-induced granulocytic differentiation as a novel potential leukocyte differentiation antigen

Leukocyte differentiation antigens (LDAs) play important roles in the immune system, by serving as surface markers and participating in multiple biological activities, such as recognizing pathogens, mediating membrane signals, interacting with other cells or systems, and regulating cell differentiation and activation. Data mining is a powerful tool used to identify novel LDAs from whole genome. LRRC25 (leucine rich repeat-containing 25) was predicted to have a role in the function of myeloid cells by a large-scale “omics” data analysis. Further experimental validation showed that LRRC25 is highly expressed in primary myeloid cells, such as granulocytes and monocytes, and lowly/intermediately expressed in B cells, but not in T cells and almost all NK cells. It was down-regulated in multiple acute myeloid leukemia (AML) cell lines and bone marrow cells of AML patients and up-regulated after all-trans retinoic acid (ATRA)-mediated granulocytic differentiation in AML cell lines and acute promyelocytic leukemia (APL; AML-M3, FAB classification) cells. Localization analysis showed that LRRC25 is a type I transmembrane molecule. Although ectopic LRRC25 did not promote spontaneous differentiation of NB4 cells, knockdown of LRRC25 by siRNA or shRNA and knockout of LRRC25 by the CRISPR-Cas9 system attenuated ATRA-induced terminal granulocytic differentiation, and restoration of LRRC25 in knockout cells could rescue ATRA-induced granulocytic differentiation. Therefore, LRRC25, a potential leukocyte differentiation antigen, is a key regulator of ATRA-induced granulocytic differentiation.

Molecular Profiling: A Case of ZBTB16-RARA Acute Promyelocytic Leukemia

Several variant RARA translocations have been reported in acute promyelocytic leukemia (APL) of which the t(11;17)(q23;q21), which results in a ZBTB16-RARA fusion, is the most widely identified and is largely resistant to therapy with all-trans retinoic acid (ATRA). The clinical course together with the cytogenetic and molecular characterization of a case of ATRA-unresponsive ZBTB16-RARA APL is described. Additional mutations potentially cooperating with the translocation fusion product in leukemogenesis have been hitherto unreported in ZBTB16-RARA APL and were sought by application of a next-generation sequencing approach to detect those recurrently found in myeloid malignancies. This technique identified a solitary, low level mutation in the CEBPA gene. Molecular profiling of additional mutations may provide a platform to individualise therapeutic management in patients with this rare form of APL.

Role of Vitamin A/Retinoic Acid in Regulation of Embryonic and Adult Hematopoiesis

Vitamin A is an essential micronutrient throughout life. Its physiologically active metabolite retinoic acid (RA), acting through nuclear retinoic acid receptors (RARs), is a potent regulator of patterning during embryonic development, as well as being necessary for adult tissue homeostasis. Vitamin A deficiency during pregnancy increases risk of maternal night blindness and anemia and may be a cause of congenital malformations. Childhood Vitamin A deficiency can cause xerophthalmia, lower resistance to infection and increased risk of mortality. RA signaling appears to be essential for expression of genes involved in developmental hematopoiesis, regulating the endothelial/blood cells balance in the yolk sac, promoting the hemogenic program in the aorta-gonad-mesonephros area and stimulating eryrthropoiesis in fetal liver by activating the expression of erythropoietin. In adults, RA signaling regulates differentiation of granulocytes and enhances erythropoiesis. Vitamin A may facilitate iron absorption and metabolism to prevent anemia and plays a key role in mucosal immune responses, modulating the function of regulatory T cells. Furthermore, defective RA/RARα signaling is involved in the pathogenesis of acute promyelocytic leukemia due to a failure in differentiation of promyelocytes. This review focuses on the different roles played by vitamin A/RA signaling in physiological and pathological mouse hematopoiesis duddurring both, embryonic and adult life, and the consequences of vitamin A deficiency for the blood system.

Developing Cures: Targeting Ontogenesis in Cancer

Cancer has long been known to histologically resemble developing embryonic tissue. Since this early observation, a mounting body of evidence suggests that cancer mimics or co-opts developmental processes to facilitate tumor initiation and progression. Programs important in both normal ontogenesis and cancer progression broadly fall into three domains: the lineage commitment of pluripotent stem cells, the appropriation of primordial mechanisms of cell motility and invasion, and the influence of multiple aspects of the microenvironment on the parenchyma. In this review we discuss how derangements in these developmental pathways drive cancer progression with a particular focus on how they have emerged as targets of novel treatment strategies.

Personalisierte Medizin in der Hämatologie am Beispiel der akuten myeloischen Leukämie

Fortschritte in der genetischen Charakterisierung von Leukämien und Lymphomen haben in den letzten Jahren zielgerichtete Therapieansätze ermöglicht. So haben zum Beispiel BCR-ABL1-inhibierende Tyrosinkinaseinhibitoren (TKI) die Behandlung der chronischen myeloischen Leukämie (CML) revolutioniert. Im Gegensatz dazu hat sich die Behandlung der akuten myeloischen Leukämie (AML) in den letzten 40 Jahren nicht wesentlich verändert, wobei neueste Erkenntnisse beginnen, auch zielgerichtete Therapien in der AML zu ermöglichen. Als sehr heterogene Erkrankung mit unterschiedlichem Ausgang, je nach AML-Subtyp, haben jüngste Fortschritte im Verständnis der AML-Biologie und der Identifizierung von Treibermutationen eine neue Ära der molekularen Therapie ermöglicht. Eine Reihe von prognostischen und prädiktiven molekularen Markern und Signalwegen wurden als neue therapeutische Ziele entdeckt, wie z. B. die Aktivierung der Fms-like-tyrosinkinase-3(FLT3)-Rezeptortyrosinkinase oder aberrante DNA-Methylierungsmuster, denen eine Vielzahl unterschiedlicher Mutationen in epigenetischen Treibern zugrunde liegt. Aber auch zielgerichtete Therapien mit monoklonalen Antikörpern und weiteren Kinaseinhibitoren sind vielversprechende Therapieoptionen, die dazu beitragen könnten, die Heilungsrate der AML weiter verbessern zu können. In diesem Übersichtsartikel werden wir die aktuellen Ansätze zielgerichteter Therapien bei der AML beleuchten und einen Ausblick auf neuartige und bevorstehende therapeutische Optionen sowie einen kurzen Überblick zu den aktuellen Optionen bei weiteren hämatologischen Neoplasien geben.

Use of retinoic acid/aldehyde dehydrogenase pathway as potential targeted therapy against cancer stem cells

A large number of studies have investigated possible drug resistance mechanisms of cancer cells and suggested strategies to overcome it. In this review, we outline the role and function of aldehyde dehydrogenase (ALDH) activity in multiple cellular functions and in cancer stem cells (CSCs) and focus on the role of retinoic acid (RA), one of the products of ALDH isozymes. We discuss our observation that ATRA and other RAs can suppress ALDH activity and decrease different ALDH isozyme proteins and result in detrimental effects on cell proliferation, invasion and chemotherapy sensitivity. We review the known uses of different RAs in the treatment of cancers. We review the use of RAs in combination with chemo-/radiotherapy and the major signaling pathways affected in different tumor types. We provide follow-up on studies that may have used our prior observation with the aim of targeting the CSCs. We conclude with summary of the findings and potential impact of published studies on future use of RAs in the targeting of CSCs and drug resistance.

Cellular arsenic transport pathways in mammals

Natural contamination of drinking water with arsenic results in the exposure of millions of people world-wide to unacceptable levels of this metalloid. This is a serious global health problem because arsenic is a Group 1 (proven) human carcinogen and chronic exposure is known to cause skin, lung, and bladder tumors. Furthermore, arsenic exposure can result in a myriad of other adverse health effects including diseases of the cardiovascular, respiratory, neurological, reproductive, and endocrine systems. In addition to chronic environmental exposure to arsenic, arsenic trioxide is approved for the clinical treatment of acute promyelocytic leukemia, and is in clinical trials for other hematological malignancies as well as solid tumors. Considerable inter-individual variability in susceptibility to arsenic-induced disease and toxicity exists, and the reasons for such differences are incompletely understood. Transport pathways that influence the cellular uptake and export of arsenic contribute to regulating its cellular, tissue, and ultimately body levels. In the current review, membrane proteins (including phosphate transporters, aquaglyceroporin channels, solute carrier proteins, and ATP-binding cassette transporters) shown experimentally to contribute to the passage of inorganic, methylated, and/or glutathionylated arsenic species across cellular membranes are discussed. Furthermore, what is known about arsenic transporters in organs involved in absorption, distribution, and metabolism and how transport pathways contribute to arsenic elimination are described.