Synergistic effect and molecular mechanism of PVA and UM171 in ex vivo expansion of primitive hematopoietic stem cells.

Umbilical cord blood (UCB) is a valuable source of hematopoietic stem cells (HSCs) used for transplantation; the number of cells in a single UCB is too small to quickly establish bone marrow (BM) implantation, and ex vivo expansion of HSCs has the potential to overcome this limitation. The purpose of this study is to explore the culture conditions conducive to the maintenance and expansion of hematopoietic stem and progenitor cells (HSPCs) and long-term hematopoietic stem cells (LT-HSCs) derived from human umbilical cord blood, compare the different effects of albumin (HSA) and polyvinyl alcohol (PVA), optimize the culture system using UM171 and investigate the molecular mechanism of PVA and UM171 promoting the expansion of primitive hematopoietic stem cells. CD34+ cells were purified from UCB using MacsCD34 beads, and then cultured in serum-free medium supplemented with cytokines for 12 days, with PVA or UM171 added according to experimental requirements; the relative percentage of different HSCs subsets after culture were detected by flow cytometry; CFU Assay Setup for detecting the multilineage differentiation potential of HSCs; RT-PCR detection of gene expression levels; reactive oxygen detection assessment of intracellular ROS levels. (1) The conditions of 20 ng/mlSCF, 100 ng/mlTPO, and 5% oxygen concentration are conducive to the maintenance of LT-HSCs. (2) Compared with HSA, PVA significantly increased the proportion of HSPCs and LT-HSCs, as well as dramatically promoted the expression of antioxidant enzymes and reduced the production of reactive oxygen species (ROS). (3) After adding UM171 to PVA-based medium, the proportion of HSPCs and LT-HSCs further increased, and downstream genes of Notch and Wnt pathways were selectively activated. (1) PVA may inhibit ROS production by upregulating the expression of antioxidant enzymes, which is beneficial for maintaining stemness and inhibiting differentiation of HSCs. (2) The antioxidant properties of PVA can delay differentiation, while UM171 can promote self-renewal by regulating the stem cell pathway, and the combination of them is beneficial for the maintenance and expansion of HSCs in vitro.

Baicalein attenuates oxidative damage in mice haematopoietic cells through regulation of PDGFRß.

Platelet-derived growth factor receptor ß (PDGFRß) plays a crucial role in murine haematopoiesis. Baicalein (BAI), a naturally occurring flavonoid, can alleviate disease damage through anti-oxidative, anti-apoptotic, and anti-inflammatory mechanisms. However, whether BAI attenuates oxidative damage in murine haematopoietic cells by PDGFRß remains unexplored. In this study, we utilized a tert-butyl hydroperoxide (TBHP)-induced BaF3 cell injury model and an ionising radiation (IR)-induced mice injury model to investigate the impact of the presence or absence of PDGFRß on the pharmacological effects of BAI. In addition, the BAI-PDGFRß interaction was characterized by molecular docking and dynamics simulations. The results show that a specific concentration of BAI led to increased cell viability, reduced reactive oxygen species (ROS) content, upregulated nuclear factor erythroid 2-related factor 2 (NRF2) expression, and its downstream target genes heme oxygenase 1 (HO-1) and NAD(P)H Quinone Dehydrogenase 1 (NQO1), and activated protein kinase B (AKT) pathway in cells expressing PDGFRß plasmid and experiencing damage. Similarly, BAI elevated lineage-Sca1+cKIT+ (LSK) cell proportion, promoted haematopoietic restoration, enhanced NRF2-mediated antioxidant response in PDGFRß+/+ mice. However, despite BAI usage, PDGFRß knockout mice (PDGFRß-/-) showed lower LSK proportion and less antioxidant capacity than the total body irradiation (TBI) group. Furthermore, we demonstrated an interaction between BAI and PDGFRß at the molecular level. Collectively, our results indicate that BAI attenuates oxidative stress injury and helps promote haematopoietic cell recovery through regulation of PDGFRß.

Neuromedin U Induces Activation of Peripheral Group 2 Innate Lymphoid Cells through the ERK Pathway in Allergic Rhinitis Patients.

INTRODUCTION: In allergic diseases, group 2 innate lymphoid cells (ILC2s) play critical roles. Neuromedin U (NMU), a highly conserved multifunctional neuropeptide, is secreted by cholinergic neurons and involved in asthma pathogenesis by amplifying lung inflammation driven by ILC2s. However, the precise effects of NMU on ILC2s in allergic rhinitis (AR) and related diseases remain unclear. METHODS: A total of 15 patients with persistent AR and 8 healthy controls (HCs) were enrolled in the study. Visual analog scale (VAS) scores are used to assess the severity of clinical symptoms in AR patients. The percentages of ILC2s in peripheral blood mononuclear cells (PBMCs) were enumerated using flow cytometry. The soluble or intracellular cytokines (IL-5 and IL-13) in PBMCs or sorted ILC2s were assessed in response to various stimuli with IL-33, NMU, IL-33 combined with extracellular signal-related kinase (ERK) inhibitor or NMU combined with ERK inhibitor in the presence of IL-2. RESULTS: We confirmed the proportion of circulating ILC2s was significantly higher in AR patients than in HCs. ILC2s levels were found to be positively related to VAS scores. We also discovered that the release of IL-5 and IL-13 in AR patients' PBMCs stimulated by NMU (p < 0.0001 and p < 0.0001, respectively) or IL-33 (p = 0.002; p = 0.044, respectively) was significantly higher than in HCs. In AR patients, NMU stimulated PBMCs or ILC2s to generate greater inflammatory factors IL-5 and IL-13 compared to IL-33. Furthermore, we observed that NMU-promoted ILC2s activation and proliferation functions were restricted when the ERK pathway was inhibited. CONCLUSION: NMU effectively activated ILC2s in AR patients to produce Th2-type cytokines, and this activation can be prevented by ERK pathway inhibitors. Our findings shed new light on the neuro-immune mechanism of AR and offer new insights into its prevention and treatment.

A new pathway for the transformation of AML in MDS: APA mechanism regulated by NUDT21 and RUNX1.

We have identified that NUDT21 plays a vital role in MDS transformations, while the transcription factor RUNX1 is essential for normal hematopoiesis, which is a high expression in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS), and we aim to explore the linkage between the two genes and new pathways for MDS transformation to AML. Prediction of RUNX1 expression levels and its relationship with NUDT21 in AML and MDS patients was performed using bioinformatics techniques and validated in patients. Using lentiviral packaging technology, NUDT21 knockdown and overexpression models were developed in AML and MDS cell lines. These models were validated using quantitative polymerase chain reaction (qPCR) and western blotting. The cell cycle, apoptosis, differentiation, and cytokines were examined by flow cytometry, CCK-8 analyzed proliferation, and the intracellular localization of NUDT21 and RUNX1 was examined by immunofluorescence. mRNA transcriptome sequencing was performed on THP-1, MUTZ-1, and Dapars analyzed SKM-1 cell lines and the sequencing data to observe the knockdown effect of NUDT21 on RUNX1. qPCR and western blot revealed a positive correlation between NUDT21 and RUNX1; both were located in the nucleus. Overexpression of NUDT21 reduced apoptosis, promoted cell proliferation, and possibly increased the invasive ability of cells. It also altered the APA site in the RUNX1 3'-UTRs region. NUDT21 regulates RUNX1 gene expression and promotes AML transformation in MDS through an APA mechanism.

Predictive Value of Small Dense Low-Density Lipoprotein in Coronary Heart Disease in the Chinese Population.

BACKGROUND: Coronary heart disease (CHD) is a global public health concern, and CHD risk assessment remains a major challenge. Therefore, in this study, the ability of small dense low-density lipoprotein (sdLDL) alone to sufficiently predict CHD risk in the Chinese population was evaluated. METHODS: Patients with CHD (139) and healthy controls (58) were included in this study. Serum sdLDL was measured using the peroxidase method. Other lipid parameters were also determined. RESULTS: The sdLDL level in the CHD group was significantly higher than that in the control group (p < 0.001). Logistic regression analysis revealed that sdLDL was an independent risk factor for CHD. Based on the receiver operating characteristic curves, the area under the curve (AUC) of sdLDL alone for CHD was 0.722. The AUC of triglycerides (TG), high-density lipoprotein (HDL), and sdLDL combined was 0.763, which was larger than that of the independent ones or combinations of any two; however, the value was not significant. CONCLUSIONS: sdLDL alone can predict CHD risk efficiently similar to the combination of TG, HDL, and sdLDL. This finding suggests that sdLDL can be considered as an ideal parameter for the preliminary diagnosis of CHD in Chinese people.

T-cell blast crisis of chronic myelogenous leukemia presented with coexisting p210 and p190 BCR-ABL transcripts and t(10;11)(q11;p15).

BACKGROUND: Blast transformation of chronic myelogenous leukemia (CML) to T lymphoblastic lymphoma/acute lymphoblastic leukemia (T-LBL/ALL) is rare, and the molecular mechanism is still unclear. CASE REPORT: A 28-year-old woman who developed T-ALL with coexpressing both p210 and p190 BCR-ABL transcripts five years after the initial diagnosis of CML in chronic phase. The proliferation of bone marrow was extremely active with blast cells over 20%. Chromosome analysis revealed t(9;22)(q34;q11) and t(10;11)(q25;p15). Flow immunophenotyping showed that blasts expressed CD4, CD7, CD11b, CD38, CD34, CD33, and cCD3. CONCLUSION: It is the first T-cell blast of CML case with coexisting p210 and p190 as well as additional chromosome translocations. Through review this case and previous reports, we will reveal that CML patients with T-lymphocyte transformation depend on potential molecular and pathological mechanism.

TET2 rs2454206, TET2 rs12498609 and ASXL1 rs3746609 single nucleotide polymorphisms in patients with myelodysplastic syndromes.

To study the association between TET2rs2454206, TET2rs12498609 and ASXL1rs3746609 and Myelodysplastic syndromes (MDS), a total of 90 MDS patients and 143 healthy volunteers were included. The clinical data, bone marrow samples of patients and peripheral blood samples of volunteers were obtained. We found TET2rs2454206 G/A genotype, TET2rs12498609 G/C genotype and ASXL1rs3746609 A/G genotype in 13.3%, 11.1%, 10.1% MDS patients and in 42.7%, 22.4%, 23.8% healthy volunteers (P < 0.001; P = 0.029; P = 0.009, respectively). TET2 rs2454206 G/A genotype was associated with higher serum LDH level in MDS (P = 0.025). Patients with TET2rs12498609 G/C genotype were characterized with higher frequency of mutated SRSF2 gene (P = 0.042) and lower occurrence rate of anemia (P = 0.026) than those with C/C genotype. ASXL1rs3746609 A/G genotype linked with higher thrombocyte counts (P = 0.02) and percent of total T lymphocyte (P = 0.029), whereas with lower percent of NK cell (P = 0.032) and B lymphocyte (P = 0.007). None of these three SNPs had impact on the overall survival and disease progression to AML. We concluded that People with TET rs2454206 G/A genotype, TET2rs12498609 G/C genotype or ASXL1rs3746609 A/G genotype were related to lower prevalence of MDS. All of the three SNPs were associated with certain laboratory features in MDS patients.

Droplet digital PCR for BCR/ABL(P210) detection of chronic myeloid leukemia: A high sensitive method of the minimal residual disease and disease progression.

OBJECTIVE: This study intended to establish a droplet digital PCR (dd-PCR) for monitoring minimal residual disease (MRD) in patients with BCR/ABL (P210)-positive chronic myeloid leukemia (CML), thereby achieving deep-level monitoring of tumor load and determining the efficacy for guided clinically individualized treatment. METHODS: Using dd-PCR and RT-qPCR, two cell suspensions were obtained from K562 cells and normal peripheral blood mononuclear cells by gradient dilution and were measured at the cellular level. At peripheral blood (PB) level, 61 cases with CML-chronic phase (CML-CP) were obtained after tyrosine kinase inhibitor (TKI) treatment and regular follow-ups. By RT-qPCR, BCR/ABL (P210) fusion gene was undetectable in PB after three successive analyses, which were performed once every 3 months. At the same time, dd-PCR was performed simultaneously with the last equal amount of cDNA. Ten CML patients with MR4.5 were followed up by the two methods. RESULTS: At the cellular level, consistency of results of dd-PCR and RT-qPCR reached R2  ≥ 0.99, with conversion equation of Y = 33.148X1.222 (Y: dd-PCR results; X: RT-qPCR results). In the dd-PCR test, 11 of the 61 patients with CML (18.03%) tested positive and showed statistically significant difference (P < .01). In the follow-up of 10 CML patients who were in MR4.5. All patients were loss of MR4.0, and 4 were tested positive by dd-PCR 3 months earlier than by RT-qPCR. CONCLUSION: In contrast with RT-qPCR, dd-PCR is more sensitive, thus enabling accurate conversion of dd-PCR results into internationally standard RT-qPCR results by conversion equation, to achieve a deeper molecular biology-based stratification of BCR/ABL(P210) MRD. It has some reference value to monitor disease progression in clinic.

Detection of PML/RARα Fusion Gene in Bone Marrow of Patients with Functionalized Graphene Oxide.

BACKGROUND: Current diagnostic methods of acute promyelocytic leukemia (APL) have some inevitable shortcomings; therefore, further studies are needed to develop more effective diagnostic methods. We used functionalized graphene oxide (GO) to detect the promyelocytic leukemia/retinoic acid receptor, α fusion gene (PML/RARα fusion gene) in bone marrow of APL patients. This method was more convenient and time-saving, and we can obtain the detection results in 1 hour. METHODS: Our group consists of 36 cases, among them are 16 cases which are PML-RARα positive, 20 cases which are PML-RARα negative. Firstly, samples were fixed, drilled, and incubated with antibody CD45. Secondly, GO, fluorescent probes, and buffer liquid were added. One hour later, samples were washed with PBS (1 x) buffer, centrifuged, and fluorescent signals were detected with flow cytometry. RESULTS: Using functional GO to carry the fluorescent probe we ascertained whether bone marrow samples contain the L type PML/RARα fusion gene. Using the probe, only cells which contain L type PML/RARα fusion gene will have fluorescent signals compared to no signals (p < 0.05). The GO detection method was accurate and has clinical diagnostic values (p < 0.05). CONCLUSIONS: The GO detection method has the advantages of accurate, time-saving, energy-saving simple operation, and no pollution.

Synergistic effect and molecular mechanism of nicotinamide and UM171 in ex vivo expansion of long-term hematopoietic stem cells.

Introduction: Several approaches to expand human hematopoietic stem cells (HSCs) have been reported, but the ability of these methods to expand long-term hematopoietic stem cells (LT-HSCs) remains to be improved, which limits the application of HSCs-based therapies. Methods: CD34+ cells were purified from umbilical cord blood using MacsCD34 beads, and then cultured for 12 d in a serum-free medium. Flow cytometry was used to detect phenotype, cell cycle distribution, and apoptosis of the cultured cells. Colony-forming cell (CFC) assays can evaluate multi-lineage differentiation potential of HSCs. Real-time polymerase chain reaction was employed to detect the expression of genes related to self-renewal programs and antioxidant activity. DCFH-DA probes were used to evaluate intracellular production of reactive oxygen species (ROS). Determination of the effect of different culture conditions on the balance of cytokine by cytometric bead array. Results: Here, we show a combination, Nicotinamide (NAM) combined with pyrimidoindole derivative UM171, can massively expand LT-HSCs ex vivo, and the expanded cells maintained the capability of self-renewal and multilineage differentiation. Additionally, our data indicated that UM171 promoted self-renewal of HSCs by inducing HSCs entry into the cell cycle and activating Notch and Wnt pathways, but the infinite occurrence of this process may lead to mitochondrial metabolism disorder and differentiation of HSCs. NAM kept HSCs in their primitive and dormant states by reducing intracellular ROS levels and upregulating the expression of stemness related genes, so we believed that NAM can act as a brake to control the above process. Conclusions: The discovery of the synergistic effect of NAM and UM171 for expanding LT-HSCs provides a new strategy in solving the clinical issue of limited numbers of HSCs.

The short isoform of the long-type PML-RARA fusion gene in acute promyelocytic leukaemia lacks sensitivity to all-trans-retinoic acid.

Alternative splicing is associated with human disease. In acute promyelocytic leukaemia (APL) patients with the long (L)-type promyelocytic leukaemia-retinoic acid receptor α fusion gene (PML-RARA), three alternative splicing isoforms can be detected: E5(+)E6(+), E5(-)E6(+), and E5(-)E6(-). This study is the first to demonstrate that alternative splicing of L-type PML-RARA is associated with time to achieve complete remission (CR) in APL. Higher expression of the E5(-)E6(-) isoform, the short isoform, was related to longer time to achieve CR. Each isoform was constructed into recombinant lentiviral vector and transfected into U937 cells. Compared with the E5(-)E6(+) and E5(+)E6(+) groups, the U937 cells with E5(-)E6(-) showed lower sensitivity to all-trans-retinoic acid treatment.

Detection of promyelocytic leukemia/retinoic acid receptor α (PML/RARα) fusion gene with functionalized graphene oxide.

An attempt was made to use functionalized graphene oxide (GO) to detect the Promyelocytic leukemia/Retinoic acid receptor α fusion gene (PML/RARα fusion gene), a marker gene of acute promyelocytic leukemia. The functionalized GO was prepared by chemical exfoliation method, followed by a polyethylene glycol grafting. It is found that the functionalized GO can selectively adsorb the fluorescein isothiocyanate (FITC)-labeled single-stranded DNA probe and quench its fluorescence. The probe can be displaced by the PML/RARα fusion gene to restore the fluorescence, which can be detected by laser confocal microscopy and flow cytometry. These can be used to detect the presence of the PML/RARα fusion gene. This detection method is verified to be fast, simple and reliable.

MEK/ERK and PI3K/AKT pathway inhibitors affect the transformation of myelodysplastic syndrome into acute myeloid leukemia via H3K27me3 methylases and de­methylases.

The transformation of myelodysplastic syndrome (MDS) into acute myeloid leukemia (AML) poses a significant clinical challenge. The trimethylation of H3 on lysine 27 (H3K27me3) methylase and de­methylase pathway is involved in the regulation of MDS progression. The present study investigated the functional mechanisms of the MEK/ERK and PI3K/AKT pathways in the MDS­to­AML transformation. MDS­AML mouse and SKM­1 cell models were first established and this was followed by treatment with the MEK/ERK pathway inhibitor, U0126, the PI3K/AKT pathway inhibitor, Ly294002, or their combination. H3K27me3 methylase, enhancer of zeste homolog (EZH)1, EZH2, demethylase Jumonji domain­containing protein­3 (JMJD3) and ubiquitously transcribed tetratricopeptide repeat on chromosome X (UTX) and H3K27me3 protein levels were determined using western blot analysis. Cell viability, cycle distribution and proliferation were assessed using CCK­8, flow cytometry, EdU and colony formation assays. The ERK and AKT phosphorylation levels in clinical samples and established models were determined, and SKM­1 cell behaviors were assessed. The levels of H3K27me3 methylases and de­methylases and distal­less homeobox 5 (DLX5) were measured. The results revealed that the ERK and AKT phosphorylation levels were elevated in patients with MDS and MDS­AML, and in mouse models. Treatment with U0126, a MEK/ERK pathway inhibitor, and Ly294002, a PI3K/AKT pathway inhibitor, effectively suppressed ERK and AKT phosphorylation in mice with MDS­AML. It was observed that mice with MDS treated with U0126/Ly294002 exhibited reduced transformation to AML, delayed disease transformation and increased survival rates. Treatment of the SKM­1 cells with U0126/Ly294002 led to a decrease in cell viability and proliferation, and to an increase in cell cycle arrest by suppressing ERK/PI3K phosphorylation. Moreover, treatment with U0126/Ly294002 downregulated EZH2/EZH1 expression, and upregulated JMJD3/UTX expression. The effects of U0126/Ly294002 were nullified when EZH2/EZH1 was overexpressed or when JMJD3/UTX was inhibited in the SKM­1 cells. Treatment with U0126/Ly294002 also resulted in a decreased H3K27me3 protein level and H3K27me3 level in the DLX5 promoter region, leading to an increased DLX5 expression. Overall, the findings of the present study suggest that U0126/Ly294002 participates in MDS­AML transformation by modulating the levels of H3K27me3 methylases and de­methylases, and regulating DLX5 transcription and expression.

Acute myeloid leukemia cells and MSC-derived exosomes inhibiting transformation in myelodysplastic syndrome.

AIMS: To investigate the mechanism of exosomes' role in the transformation of MDS to AML. METHODS: Exosomes in culture supernatants of MDS and AML cell lines, were extracted by ultrafiltration and identified in three ways: morphology, size, and exosome protein surface markers. Exosomes from AML cell lines were then co-cultured with MDS cell lines and their impacts on MDS cell microenvironment, proliferation, differentiation, cell cycle, and apoptosis were analyzed by CCK-8 assay and flow cytometry. Furthermore, exosomes from MSC were extracted for further authentication. RESULTS: The transmission electron microscopy, nanoparticle tracking analysis, Western blotting, and flow cytometry methods all verify that ultrafiltration is a reliable method to extract exosomes in the culture medium. Exosomes from AML cell lines inhibit the proliferation of MDS cell lines, block cell cycle progression, and promote apoptosis and cell differentiation. It also leads to increased secretion of tumor necrosis factor-α (TNF-α) and reactive oxygen species (ROS) in MDS cell lines. In addition, MSC-derived exosomes were found to inhibit the proliferation of MDS cell lines, arrest cell cycle progression, promote apoptosis, and inhibit differentiation. CONCLUSION: Ultrafiltration is a proper methodology in extracting exosomes. The exosomes of AML origin and MSC origin may play a role in MDS leukemia transformation via targeting TNF-α/ROS-Caspase3 pathway.

EZH2/EHMT2 Histone Methyltransferases Inhibit the Transcription of DLX5 and Promote the Transformation of Myelodysplastic Syndrome to Acute Myeloid Leukemia.

Myelodysplastic syndrome (MDS) is characterized by clonal hematopoiesis and impaired differentiation, and may develop to acute myeloid leukemia (AML). We explored the mechanism of histone methyltransferase EZH2/EHMT2 during the transformation of MDS into AML. Expression of EZH2/EHMT2 in patients and NHD13 mice was detected. EZH2 and EHMT2 were silenced or overexpressed in SKM-1 cells. The cell proliferation and cycle were evaluated. Levels of DLX5, H3K27me3, and H3K9me2 in SKM-1 cells were detected. Binding of DLX5 promoter region to H3K27me3 and H3K9me2 was examined. Levels of H3K27me3/H3K9me2 were decreased by EZH2/EHMT2 inhibitor (EPZ-6438/BIX-01294), and changes of DLX5 expression and cell proliferation were observed. EZH2 was poorly expressed in MDS patients but highly expressed in MDS-AML patients. EHMT2 was promoted in both MDS and MDS-AML patients. EZH2 expression was reduced and EHMT2 expression was promoted in NHD13 mice. NHD13 mice with overexpressing EZH2 or EHMT2 transformed into AML more quickly. Intervention of EZH2 or EHMT2 inhibited SKM-1 cell proliferation and promoted DLX5 expression. When silencing EZH1 and EZH2 in SKM-1 cells, the H3K27me3 level was decreased. EZH2 silencing repressed the proliferation of SKM-1 cells. Transcription level of DLX5 in SKM-1 cells was inhibited by H3K27me3 and H3K9me2. Enhanced DLX5 repressed SKM-1 cell proliferation. In conclusion, EZH2/EHMT2 catalyzed H3K27me3/H3K9me2 to inhibit the transcription of DLX5, thus promoting the transformation from MDS to AML.

[Quantitative Analysis on Immunophenotype of CD34+ Myeloid Precursor Cells in Myelodysplastic Syndrome and Its Correlation with Clinical Features].

OBJECTIVE: To investigate the quantitative expression of immunophenotype of CD34+ myeloid precursor cells in myelodysplastic syndrome (MDS) patients and its correlation with clinical characteristics, and understand the effect of quantitative expression of CD7 and CD117 on the prognosis of low-risk MDS patients. METHODS: Multi-parameter flow cytometry (FCM) was used to detect the proportion and mean fluorescence intensity (MFI) of each antigen of bone marrow CD34+ myeloid precursor cells in 79 MDS patients. The correlation between the expression level of each immune marker and clinical characteristics was compared. The effects of quantitative expressions of CD7 and CD117 on the overall survival rate of low-risk patients were explored. RESULTS: Bone marrow blast cell proportion (P<0.01), RBC level (P<0.01), and Hb level (P<0.05) of high-risk MDS patients were higher, while EPO level (P<0.05) was lower than those of low-risk patients. The proportion of CD34+ blast cells (P<0.01), the proportion of CD117 (P<0.05) and the MFI of CD7 (P<0.05) were higher in high-risk patients than those in low-risk patients, but the MFI of CD123 was lower (P<0.05). In high-risk MDS patients, CD15/CD34 (MFI) and CD19/CD34 (MFI) positively correlated with the proportion of total T cells (r=0.458; r=0.505), while CD19/CD34 (%) and CD19/CD34 (MFI) negatively correlated with WBC levels (r=-0.469; r=-0.503). In low-risk MDS patients, CD34+ (%) positively correlated with bone marrow erythrocyte proportion, PLT level and neutrophil level (r=0.426; r=0.486; r=0.495), but negatively correlated with LDH level (r=-0.421); WT1 expression level was positively correlated with CD10/CD34 (%), CD10/CD34 (MFI) and CD117/CD34 (MFI) (r=0.745; r=0.800; r=0.434), while negatively correlated with CD11b/CD34 (%)(r=-0.457); CD19/CD34 (%) and CD71/CD34 (MFI) negatively correlated with NK cell proportion (r=-0.786; r=-0.514); CD10/CD34 (%) positively correlated with Th/Ts, while CD7/CD34 (MFI) negatively correlated with the proportion of Th cells (r=0.738; r=-0.513); HLADR/CD34 (%) and HLADR/CD34 (MFI) negatively correlated with PLT level (r=-0.461; r=-0.445), while HLADR/CD34 (MFI) positively correlated with bone marrow NAP fraction (r=0.552). The quantitative expression of CD7 and CD117 had no significant effect on the overall survival rate of low-risk MDS patients. CONCLUSION: The immunophenotype of CD34+ myeloid precursor cell in different risk groups in MDS patients is related to clinical characteristics. Bone marrow cell morphology, clinical and laboratory features and immunophenotype will be of great significance to the diagnosis, clinical classification and prognosis evaluation of MDS patients.

Alternative Polyadenylation: a new frontier in post transcriptional regulation.

Polyadenylation of pre-messenger RNA (pre-mRNA) specific sites and termination of their downstream transcriptions are signaled by unique sequence motif structures such as AAUAAA and its auxiliary elements. Alternative polyadenylation (APA) is an important post-transcriptional regulatory mechanism that processes RNA products depending on its 3'-untranslated region (3'-UTR) specific sequence signal. APA processing can generate several mRNA isoforms from a single gene, which may have different biological functions on their target gene. As a result, cellular genomic stability, proliferation capability, and transformation feasibility could all be affected. Furthermore, APA modulation regulates disease initiation and progression. APA status could potentially act as a biomarker for disease diagnosis, severity stratification, and prognosis forecast. While the advance of modern throughout technologies, such as next generation-sequencing (NGS) and single-cell sequencing techniques, have enriched our knowledge about APA, much of APA biological process is unknown and pending for further investigation. Herein, we review the current knowledge on APA and how its regulatory complex factors (CFI/IIm, CPSF, CSTF, and RBPs) work together to determine RNA splicing location, cell cycle velocity, microRNA processing, and oncogenesis regulation. We also discuss various APA experiment strategies and the future direction of APA research.

Identification of Two Novel Truncated Transcripts of Janus Kinase 2 Gene.

Jak2 is a nonreceptor tyrosine kinase that plays a critical role in signal transduction through an abundance of receptors, such as erythropoietin receptor. In this paper, we report two previously unknown transcripts of Jak2 gene. One transcript deletes the 77nt of 3' end exon 10 of the Jak2 gene, resulting in a frameshift that introduces a stop codon in the downstream exon and produces a truncated protein of 421 amino acids if translated. The other transcript skips the entire exon 10, leading to a premature stop codon in the adjacent exon 11, producing a truncated protein of 414 amino acids if translated. Therefore, the physiological significance of the expression of two novel transcripts in healthy volunteers and patients with myeloproliferative neoplasms, acute leukemia, and chronic myeloid leukemia needs to be investigated further.

Disulfiram/cytarabine eradicates a subset of acute myeloid leukemia stem cells with high aldehyde dehydrogenase expression.

Most patients with acute myeloid leukemia (AML) achieve complete remission (CR) after induction chemotherapy, however, in some patients, the disease subsequently relapses and may lead to death. Leukemia stem cells (LSC) have been identified as the main cause for recurrence. Increased aldehyde dehydrogenase (ALDHhigh) activity in a variety of cancer stem cells prevents effective action of chemotherapeutic drugs. In this study, we found that approximately 50.7% of AML patients had ALDHhigh, and the presence of ALDHhigh stem cells was associated with poor cytogenetic prognosis. Lentiviral vector transduced ALDHhigh leukemia cell lines are insensitive to the conventional chemotherapy drug cytarabine, and inhibition of ALDH activity by disulfiram (DSF) can increase the sensitivity of ALDHhigh leukemia cells to cytarabine. Unlike traditional chemotherapy drugs, DSF is not toxic to healthy umbilical cord blood stem cells. An ALDHhigh leukemia cell xenograft model was established using immunodeficient mice to mimic the disease environment, and DSF and cytarabine were found to eliminate the ALDHhigh leukemia cells in transplanted mice while not affecting the healthy blood cells of mice. These findings suggest that DSF may have therapeutic potential by inhibiting ALDH activity and thereby increasing chemosensitivity.

[Effect of Signal Transduction Pathway Gene Mutations on the One- course Induced Remission Rate and Analysis of Clinical Characteristics in Patients with CBF-AML].

OBJECTIVE: To investigate the effect of other gene mutations outside the fusion gene on the first complete remission (CR1) induced by one course of induction chemotherapy in patients with core binding factor-associated acute myeloid leukemia (CBF-AML). METHODS: DNA was extracted from bone marrow or peripheral blood samples of newly diagnosed CBF-AML patients admitted to the Hematology Department of the Second Hospital of Shanxi Medical University from January 2015 to January 2019. Next-generation sequencing was used for detection of 34 kinds of hematologic malignancy-related gene mutations in patients with CBF-AML, the effect of related gene mutations on the first complete remission (CR1) rate in one course of induction chemotherapy was analyzed by combineation with clinical characteristics. RESULTS: 34 kinds of genes in bone marrow or peripheral blood of 43 patients were detected by high throughput sequencing and the gene mutations were detected in 16 out of 34 genes. The mutation rate of KIT gene was the highest (48.8%), followed by NRAS (16.3%), ASXL1 (16.3%), TET2 (11.6%), CSF3R (9.3%), FLT3 (9.3%), KRAS (7.0%). The detection rates of mutations in different functional genes were as follows: genes related with signal transduction pathway (KIT, FLT3, CSF3R, KRAS, NRAS, JAK2, CALR, SH2B3, CBL) had the highest mutation frequency (72.1% (31/43); epigenetic modification gene mutation frequency was 30.2% (13/43), including ASXL1, TET2, BCOR); transcriptional regulation gene mutation frequency was 7.0% (3/43), including ETV6, RUNX1, GATA2). Splicing factor related gene mutation frequency was 2.3% (1/43), including ZRSR2). The CR1 rate was 74.4% after one course of induction chemotherapy. At first diagnosis, patients with low expression of WT1 (the median value of WT1 was 788.9) were more likely to get CR1 (P=0.032) and the RFS of patients who got CR1 after one course of induction chemotherapy was significantly longer than that of patients without CR1 [7.6 (2.2-44.1) versus 5.8 (1-19.4), (P=0.048)]. The rate of CR1 in the signal transduction pathway gene mutation group was significantly lower than that in non-mutation group (64.5% vs 100%) (P=0.045), while the level of serum hydroxybutyrate dehydrogenase (HBDH) was significantly higher than that in non-mutation group [(418 (154-2702) vs 246 (110-1068)] (P=0.032). There was no difference in CD56 expression between the two groups (P=0.053), which was limited to the difference between (≥20%) expression and non-expression. (P=0.048). CONCLUSION: CBF-AML patients with signal transduction pathway gene mutation are often accompanied by high HBDH level and CD56 expression, moreover, the remission rate induced by one course of treatment is low.