The aim of this study was to determine the efficacy and safety of treatment of pediatric acute promyelocytic leukemia (APL) with single-agent arsenic trioxide (ATO). A total of 19 children (< 15 years of age) with newly diagnosed APL were treated with single-agent ATO for remission induction and postremission therapy. Seventeen of the children (89.5%) achieved complete hematologic remission, and 2 early deaths occurred from intracranial hemorrhage. ATO-induced leukocytosis was observed in 13 (68.4%) patients. Other ATO-related toxicities were minimal and transient. Postremission ATO therapy continued for 3 years; the most common side effect was ATO-induced neutropenia. With a median follow-up of 53 months (range, 23-76 months), the calculated 5-year overall survival and eventfree survival were 83.9% and 72.7%, respectively, which are comparable with results achieved by the use of ATRA plus chemotherapy, which is the standard therapy for APL. No chronic arsenic toxicity or second malignancies were found during the follow-up period, and arsenic retention was not significant in patients off treatment more than 24 months. IntroductionAcute promyelocytic leukemia (APL) accounts for approximately 10% of childhood acute myeloid leukemia. [1][2][3][4] APL is characterized by the French-American-British M3 subtype morphology, a distinctive immunophenotype, and, in the majority of cases, there is a t(15;17) chromosomal translocation that generates the promyelocytic leukemia-retinoic acid receptor-␣ (PML-RARa) fusion gene. This specific genetic lesion determines the unique response to treatment with all-trans retinoic acid (ATRA) or arsenic trioxide (ATO). 5 Since the introduction of ATRA in the 1980s and ATO in the 1990s, the strategy for treating APL has shifted from conventional chemotherapy to cancer cell differentiation and cancer-targeted therapy. The combination of ATRA and anthracycline-based chemotherapy is currently the standard approach to treat newly diagnosed APL. With this regimen, the hematologic complete remission (HCR) rate has improved significantly, to more than 90%; 5-year disease-free survival is more than 70%. 5-10 However, some problems still remain; notably, ATRA-related side effects appear to be more pronounced in children than in adult patients, 4,11-13 the optimal postremission therapy still remains to be defined, and approximately 20% to 30% of patients eventually relapse and develop drug resistance.ATO has proven to be another highly effective agent in APL therapy. 14-21 ATO differs from ATRA because of its dual effects of inducing partial differentiation and apoptosis of APL cells. Although highly efficacious, ATO is most commonly used in refractory or relapsed APL for inducing remission. It has previously been shown that single-agent ATO is equally effective in inducing remission in newly diagnosed cases of adult APL. However, little is known about the use of single-agent ATO in the treatment of children with APL. The optimal dosage and route of administration during remission induction and ...

BackgroundAcute myeloid leukemia can develop as myoblasts infiltrate into organs and tissues anywhere other than the bone marrow, which called extramedullary infiltration (EMI), indicating a poor prognosis. Circular RNAs (circRNAs) are a novel class of non-coding RNAs that feature covalently closed continuous loops, suggesting their potential as micro RNA (miRNA) “sponges” that can participate in biological processes and pathogenesis. However, investigations on circRNAs in EMI were conducted rarely. In this study, the overall alterations of circRNAs and their regulatory network between EMI and non-EMI AML were delineated.MethodsCircRNA and whole genome microarrays derived from EMI and non-EMI AML bone marrow mononuclear cells were carried out. Functional analysis was performed via Gene Ontology and KEGG test methods. The speculated functional roles of circRNAs were based on mRNAs and predicted miRNAs that played intermediate roles. Integrated bioinformatic analysis was conducted to further characterize the circRNA/miRNA/mRNA regulatory network and identify the functions of distinct circRNAs. The Cancer Genome Atlas (TCGA) data were acquired to evaluate the poor prognosis of distinct target genes of circRNAs. Reverse transcription-quantitative polymerase chain reaction was conducted to identify the expression of has_circRNA_0004520. Connectivity map (CMap) analysis was further performed to predict potential therapeutic agents for EMI.Results253 circRNAs and 663 genes were upregulated and 259 circRNAs and 838 genes were downregulated in EMI compared to non-EMI AML samples. GO pathways were enriched in progress including cell adhesion (GO:0030155; GO:0007155), migration (GO:0016477; GO:0030334), signal transduction (GO:0009966; GO:0007165) and cell–cell communication. Overlapping circRNAs envolved in pathways related to regulate cell–cell crosstalk, 17 circRNAs were chosen based on their putative roles. 7 target genes of 17 circRNAs (LRRK1, PLXNB2, OLFML2A, LYPD5, APOL3, ZNF511, and ASB2) indicated a poor prognosis, while overexpression of PAPLN and NRXN3 indicated a better one based on data from TCGA. LY-294002, trichostatin A and SB-202190 were identified as therapeutic candidates for EMI by the CMap analysis.ConclusionTaken together, this study reveals the overall alterations of circRNA and mRNA involved in EMI and suggests potential circRNAs may act as biomarkers and targets for early diagnosis and treatment of EMI.Electronic supplementary materialThe online version of this article (10.1186/s12967-018-1726-x) contains supplementary material, which is available to authorized users.

Background/Aims: Pulmonary arterial endothelial plexiform lesions are a basic pathological change associated with pulmonary vascular remodeling and are characterized by the formation of tumorlets as a result of over-growth of endothelial cells. Accumulating evidence suggests that platelet-derived growth factor (PDGF) participates in regulating the progression of pulmonary arterial hypertension. However, whether PDGF promotes the survival of pulmonary arterial endothelial cells (PAECs), as well as the specific molecular mechanisms that underlie its actions, remains unknown. Methods: MTT assays, caspase-3 and caspase-9 activity assays and western blot analysis were performed. Results: We found that both the mRNA and protein expression of PDGF-B was induced by hypoxia and that the inhibitory effects exerted by hypoxia on apoptosis were attenuated by inhibitors of PDGF beta. Moreover, PDGF-B inhibited apoptosis in a dose-dependent manner by stimulating the phosphorylation of both Akt and Stat3, and the PI3K/AKT pathway serves as an up-stream participant in the Stat3 activation stimulated by PDGF-B. Additionally, the anti-apoptotic effects of PDGF-B were abolished when PAECs were treated with either an inhibitor or small interfering RNA targeting Stat3. Conclusions: These observations suggest that PDGF-B is induced by hypoxia and protects against apoptosis via the PI3K/Akt/Stat3 signaling pathway.

BACKGROUND:The prognosis of acute promyelocytic leukemia (APL) in the elderly is poorer than that of younger patients after treatment with all-trans retinoic acid plus chemotherapy, which is the current standard therapy for APL. A significantly higher mortality during consolidation therapy was found, which is mainly due to deaths from sepsis following chemotherapy-induced myelosuppression. METHODS: A total of 33 patients aged 60 years or older with de novo APL were treated with single-agent arsenic trioxide (ATO) for remission induction and postremission therapy. The postremission therapy continued for up to 4 years. RESULTS: Twentynine patients (87.9%) achieved a hematologic complete remission, and the most common adverse event during remission induction was leukocytosis (63.6%). Definite differentiation syndrome was observed in 5 patients. Nonhematologic adverse events were all manageable and reversible. Twenty-eight patients proceeded to postremission therapy. Adverse effects during postremission therapy were mild, transient, and no treatment was required. No patients died from ATO-related toxicities. With a median follow-up of 99 months, the 10-year cumulative incidence of relapse, overall survival, disease-free survival, and cause-specific survival were 10.3%, 69.3%, 64.8%, and 84.8%, respectively, which are comparable with those in the younger APL partners. No significant risks for development of chronic arsenicosis or second malignancy were observed during the follow-up period. CONCLUSIONS: The results indicate that the single-agent ATO regimen is safe and effective with long-term durable remission, and could be used as first-line treatment

This study aimed to evaluate treatment response, survival, safety profiles, and predictive factors to chimeric antigen receptor T cell (CAR-T) therapy in Chinese patients with relapsed or refractory B cell acute lymphoblast leukemia (R/R BALL). 39R/R BALL patients who underwent CART therapy were included. Baseline data were collected from patients' electronic medical records. Patients' peripheral bloods, bone marrow aspirates, and biopsies were obtained for routine examination, and treatment response and survival profiles as well as adverse events were evaluated. The rates of complete remission (CR), CR with minimal residual disease (MRD) negative/positive, and bridging to hematopoietic stem-cell transplantation (HSCT) were 92.3%, 76.9%, 15.4%, and 43.6%, respectively. The median event-free survival (EFS) was 11.6 months (95% confidence interval (CI): 4.0-19.2 months) and median overall survival (OS) was 14.0 months (95% CI: 10.9-17.1 months). Bridging to HSCT independently predicted better EFS and OS, while high bone marrow blasts level independently predicted worse EFS. The incidence of cytokine release syndrome (CRS) was 97.4%, and refractory disease as well as decreased white blood cell independently predicted higher risk of severe CRS. Other common adverse events included hematologic toxicities (grade I: 5.1%, grade II: 7.7%, grade III: 17.9%, grade IV: 69.2%), neurotoxicity (28.2%), infection (38.5%), and admission for intensive care unit (10.3%). In conclusion, CART therapy presents with promising treatment response, survival and safety profiles, and higher disease burden predicts worse survival as well as increased risk of severe CRS in Chinese R/R BALL patients.