The RNA m6A Reader YTHDF1 Is Required for Acute Myeloid Leukemia Progression.

N6-methyladenosine (m6A), the most abundant modification in mRNAs, has been defined as a crucial modulator in the progression of acute myelogenous leukemia (AML). Identification of the key regulators of m6A modifications in AML could provide further insights into AML biology and uncover more effective therapeutic strategies for patients with AML. Here, we report overexpression of YTHDF1, an m6A reader protein, in human AML samples at the protein level with enrichment in leukemia stem cells (LSC). Whereas YTHDF1 was dispensable for normal hematopoiesis in mice, depletion of YTHDF1 attenuated self-renewal, proliferation, and leukemic capacity of primary human and mouse AML cells in vitro and in vivo. Mechanistically, YTHDF1 promoted the translation of cyclin E2 in an m6A-dependent manner. Structure-based virtual screening of FDA-approved drugs identified tegaserod as a potential YTHDF1 inhibitor. Tegaserod blocked the direct binding of YTHDF1 with m6A-modified mRNAs and inhibited YTHDF1-regulated cyclin E2 translation. Moreover, tegaserod reduced the viability of patient-derived AML cells in vitro and prolonged survival in patient-derived xenograft models. Together, our study defines YTHDF1 as an integral regulator of AML progression by regulating the expression of m6A-modified mRNAs, which might serve as a potential therapeutic target for AML. SIGNIFICANCE: The m6A reader YTHDF1 is required for progression of acute myelogenous leukemia and can be targeted with the FDA-approved drug tegaserod to suppress leukemia growth.

Thalidomide induce response in patients with corticosteroid-resistant or relapsed ITP by upregulating Neuropilin-1 expression.

BACKGROUND: Immune thrombocytopenia (ITP) is an immune-mediated acquired autoimmune hemorrhagic disease. About one-third of patients are unresponsive to first-line therapies. Thalidomide (THD) as an immunomodulatory agent is now used to treat several autoimmune disorders. Therefore, we assessed the safety and efficacy of THD in corticosteroid-resistant or relapsed ITP patients, and preliminarily explore its mechanism. METHODS: 50 newly-diagnosed ITP patients and 47 healthy volunteers were enrolled in this study. Additionally, 17 corticosteroid-resistant or relapsed ITP patients were recruited, with 7 cases in the rhTPO + THD group and 10 cases in the THD monotherapy group. Overall response rate at 6, 12, and 24 months were assessed. Levels of Neuropilin-1(NRP-1), regulatory T cells (Tregs) and regulatory B cells (Bregs) were detected. RESULTS: Expression of NRP-1, Tregs and Bregs were reduced in newly-diagnosed ITP patients. In vitro, THD treatment upregulated expression of NRP-1and Tregs only in ITP patients. As for corticosteroid-resistant or relapsed ITP patients, overall response rate at 6, 12, and 24 months was 85.7%, 57.1% and 100% in the rhTPO + THD group and 60%, 75% and 83.3% in the THD group, respectively. Additionally, rhTPO plus THD or THD therapy significantly increased the levels of NRP-1, Tregs and Bregs in responders. CONCLUSIONS: Our study shows for the first time that NRP-1 is involved in the pathogenesis of ITP, THD could induce response in ITP patients by upregulating NRP-1 expression and restoring the proportion of Tregs and Bregs. THD might be served as a novel therapeutic agent in corticosteroid-resistant or relapsed ITP patients.

Effects of exogenous IL-37 on the biological characteristics of human lung adenocarcinoma A549 cells and the chemotaxis of regulatory T cells.

BACKGROUND: This study aims to investigate the effects of exogenous interleukin (IL)-37 on the biological characteristics of human lung adenocarcinoma A549 cells and the chemotaxis of regulatory T (Treg) cells. METHODS: After isolating the CD4+ CD25+ Treg cells from the peripheral blood, flow cytometry was used to detect the purity of the Treg cells. A549 cells were divided into blank (no transfection), empty plasmid (transfection with pIRES2-EGFP empty plasmid) or IL-37 group (transfection with pIRES2-EGFP-IL-37 plasmid). RT-PCR was used to detect mRNA expression of IL-37 and ELISA to determine IL-37 and MMP-9 expressions. Western blotting was applied to detect the protein expressions of PCNA, Ki-67, Cyclin D1, CDK4, cleaved caspase-3 and cleaved caspase-9. MTT assay, flow cytometry, scratch test and transwell assay were performed to detect cell proliferation, cycle, apoptosis, migration and invasion. Effect of exogenous IL-37 on the chemotaxis of Treg cells was measured through transwell assay. Xenograft models in nude mice were eastablished to detect the impact of IL-37 on A549 cells. RESULTS: The IL-37 group had a higher IL-37 expression, cell apoptosis in the early stage and percentage of cells in the G0/G1 phase than the blank and empty plasmid groups. The IL-37 group had a lower MMP-9 expression, optical density (OD), percentage of cells in the S and G2/M phases, migration, invasion and chemotaxis of CD4+CD25+ Foxp3+ Treg cells. The xenograft volume and weight of nude mice in the IL-37 group were lower than those in the blank and empty plasmid groups. Compared with the blank and empty plasmid groups, the IL-37 group had significantly reduced expression of PCNA, Ki-67, Cyclin D1 and CDK4 but elevated expression of cleaved caspase-3 and cleaved caspase-9. CONCLUSION: Therefore, exogenous IL-37 inhibits the proliferation, migration and invasion of human lung adenocarcinoma A549 cells as well as the chemotaxis of Treg cells while promoting the apoptosis of A549 cells.

[Detection and analysis of gene polymorphism in hepatitis B virus C region].

OBJECTIVE: To explore the variations of gene C in hepatitis B viruses between hepatitis B patients and healthy carriers, and provide experimental evidences for analysis of virus gene mutations acting on the virus material science and response of the body to the virus. METHODS: The virus DNA load in hepatitis B patients and healthy blood donors was investigated by real-time polymerase chain reaction (PCR). Gene sequence analysis was taken to detect gene polymorphism, and all the success samples were compaired with standard strain by DNAstar. RESULTS: (1)G Compared with standard strain, C region in all samples had mutations, there were 31 mutations in at least 2 samples (3 mutations in gene PreC and 28 mutations in gene C), including 9 missense mutations, 1 chain termination mutation and 21 synonymous mutation. Mutations nt 1827 c-->a and nt 2221 c-->t existed in all the samples, and most samples had 6 synonymous mutations. Four hepatitis B patients had mutation nt1896 g-->a, and another 4 patients had 2 mutations, namely, S87G and I97F (or 197L) in HBcAg CTL recognition episome. (2) The success ratio of amplification and sequencing of HBV DNA was closely associated with its copy numbers. In the present study, copy numbers of HBV DNA which were successfully amplified and sequenced were almost more than 40 193/ml. CONCLUSIONS: HBV genome were easily affected by nucleotide mutations, 2 residues had mutations in gene of C region, which is firstly reported, suggesting these mutations may be geographical restricted. Mutations in gene of C region may either change the structure and function of HBeAg and HBcAg, which may further induce the escape of immune clearance for HBV or influence the detection of HBsAg or HBeAg, which may creat new problems for the prevention, diagnosis and treatment of hepatitis B.

Ginsenoside Rh2 inhibits glioma cell proliferation by targeting microRNA-128.

AIM: To examine the influence of ginsenoside Rh2 (Rh2), a triterpene saponin extracted from the traditional medicinal plant ginseng, on the expression of miRNAs in human glioma cells. METHODS: The expression profile of miRNA (miR) was analyzed in human U251, T98MG and A172 glioma cells using a miRNA array and quantitative real-time PCR. Cell viability was assessed using a colorimetric assay (cell counting kit-8). Transfection of miR-128 was performed using Lipofectamine 2000. Caspase 3 activity was determined using a caspase colorimetric assay kit. Apoptosis was assessed using annexin V and propidium iodide staining. Protein expression was determined with Western blot analysis. miRNA-128 targeting activity was measured using a luciferase reporter assay. RESULTS: In U251 cells treated with Rh2 (12 µg/mL), 14 of 452 human miRNAs were up-regulated and 12 were down-regulated as detected with the miRNA array assay. The up-regulation of miR-128 by Rh2 was further verified in human U251, T98MG and A172 cells using quantitative real-time PCR. In U251 cells, transfection of a miR-128 inhibitor (50 nmol/L) prevented the overexpression of miR-128 by Rh2, and significantly blunted Rh2-induced cytotoxicity, apoptosis, caspase 3 activation, transcriptional activation of E2F3a, a miR-128 target gene, as well as E2F3a protein expression. CONCLUSION: The anti-proliferative effect of Rh2 in human glioma cells was mediated in part through up-regulation of miRNA-128 expression.

Functional magnetic resonance imaging (fMRI)-aided therapeutics of Chinese speech area-related lesions: screening of fMRI-stimulating mode and its clinical applications.

BACKGROUND: Language area-related lesion is a serious issue in neurosurgery. Removing the lesion in the language area and at the same time preserving language functions is a great challenge. AIM: In this study, we aimed to screen functional magnetic resonance imaging (fMRI) based task types suitable for activation of Broca and Wernicke areas in Chinese population, characterize lesion properties of functional area of Chinese language in brain, and assess the potential of fMRI-guided neuronavigation in clinical applications. MATERIALS AND METHODS: Blood oxygen level-dependent fMRI has been used to localize language area prior to operation. We carried out extensive fMRI analyses and conducted operation on patients with lesions in speech area. RESULTS: fMRI tests revealed that the reciting task in Chinese can steadily activate the Broca area, and paragraph comprehension task in Chinese can effectively activate the Wernicke area. Cortical stimulation of patients when being awake during operation validated the sensitivity and accuracy of fMRI. The safe distance between language activation area and removal of the lesion in language area was determined to be about 10 mm. Further investigation suggested that navigation of fMRI combined with diffuse tensor imaging can decrease the incidence of postoperative dysfunction and increase the success rate for complete removal of lesion. CONCLUSION: Taken together, these findings may be helpful to clinical therapy for language area-related lesions.

[Effects of natural killer cells on engraftment and reconstitution of hematopoiesis and immunity in mice undergoing allogeneic bone marrow transplantation].

The aim of this study was explore the effect of natural killer (NK) cells on engraftment and reconstitution of hematopoiesis and immunity in mice undergoing allogeneic bone marrow transplantation (allo-BMT). Lethally and nonlethally irradiated BALB/c (H-2(d)) mice were transplanted with C57BL/6 (H-2(b)) bone marrow plus donor peripheral T cells and/or NK cells. Recipient CD34(+), H-2K(b+), CD3(+) and CD19(+) cells were detected by flow cytometry; peripheral blood leukocytes were counted by auto-cytometry; survival rates, engraftment, hematopoietic and immune recovery of recipients in different transplant groups were then observed. The results indicated that as compared with lethally irradiated and allo-BMT group without infusion of NK cells, the survival rate in lethally irradiated and allo-BMT group with infusion of NK cells significantly enhanced (survival rates at 60 days were 70% and 0.0% respectively); leukocyte count, expression level of CD19(+) cell and CD34(+) cell count recovered rapidly; expression level of H-2K(b+) cells obviously increased [(86.68 +/- 4.45)% vs (4.68 +/- 0.32)%]; expression level of CD3(+) cell at day 28 after transplantation obviously decreased [(33.69 +/- 3.36)% vs (50.40 +/- 5.06)%, p < 0.01], at day 60 there was not significant difference between the 2 groups (p > 0.05). In nonlethally irradiated and allo-BMT group without NK cell infusion, the expression level of H-2K(b+) at day 30 after transplantation significantly decreased, and reduced to level before transplantation at day 60; while expression of H-2K(b+) yet could be detected with > 80% at day 60 after transplantation in group infused with high and low concentration of NK cells. It is concluded that in allo-BMT mice, alloreactive NK cell inhibits graft rejection, enhances engraftment, promotes the reconstitution of hematopoiesis and immunity, and increases survival rates.