Objective:To screen m6A modification-related genes, and to establish a prognostic model in patients with FLT3 mutated acute myeloid leukemia(AML), especially in older patients and to evaluate the prognostic efficiency of the model.Methods:Gene expression omnibus(GEO)datasets were used to analyze abnormally expressed m6A enzymes and reading proteins in FLT3 mutated AML; Correlation analysis was used to screen m6A modified-related genes in expression profiles.By integrating TCGA and BEAT data, 83 FLT3 mutated AML patients were included, and 32 of them were older than 60 years.Univariate Cox analysis and Lasso regression were conducted to construct the risk model.Kaplan-Meier curve and time-dependent receiver operating characteristic curve(tROC)were used to evaluate the prognostic efficiency of the model; subgroup analysis was conducted in the older patients.The concordance index(C-index)and calibration curve were used to evaluate the discrimination and accuracy of the model.Results:14 m6A modification enzymes or reading proteins were abnormally expressed in patients with FLT3 mutated AML.Correlation analysis filtered out 2 476 m6A related genes in expression profile.In TCGA and BEAT integrated data, univariate Cox analysis identified 132 prognostic genes.Lasso regression selected seven candidate genes to establish the prognostic risk model, including AKAP9, AVEN, DMCA1, DPYD, FAR2, GPHN and SPECC1L.Kaplan-Meier curve showed that high-risk group of the model had significantly shorter overall survival with a hazard ratio( HR)of 5.08(95% CI: 2.54-10.14, P<0.001).The area under the curve(AUC)in tROC for 1-year survival was 0.83; the C-index of risk model was 0.737.In older patients, the hazard ratio( HR)of the risk model for 1-year overall survival was 3.40(95% CI: 1.25-9.24, P=0.017)with an AUC of 0.79. Conclusions:The risk model based on m6A modified-related genes has some predictive value in assessing the prognosis of patients with FLT3 mutated AML, especially indicative to prognosis prediction in the elderly.

N6-Methyladenosine (m6A) is one of the most prevalent RNA modifications in mammals. The m6A modification is catalyzed by m6A writers or erasers and involved in various RNA metabolic processes with the recognition by m6A readers. Recently, emerging studies have shown m6A modification is pivotal in fundamental bioprocesses including cell homeostasis and oxidative stress, programmed cell death, cell metabolism, and immune regulation, and accounts for tumoral occurrence and development. To date, abnormal m6A levels and dysregulated related enzymes participate in tumorigenesis and chemoresistance among acute leukemias, chronic myeloid leukemia, multiple myeloma, lymphomas, thus influencing patient prognosis. The mechanisms of m6A modification are sophisticated and varied in different types of malignancies or subtypes. Screening appropriate patients to apply m6A-targeted inhibitors is instructive to the precise treatment of hematological malignancies.

Objective To study the mechanism of platelet aggregation induced by Streptococcus suis serotype 2 muramidase-released protein (MRP) and to provide scientific proof and theoretical basis for clinical treatment of patients with Streptococcus suis infection. Methods Nickel column affinity chromatogra-phy was used to purify recombinant proteins of MRP-N and MRP-C. Platelet aggregometer, thromboelastog-raphy (TEG) and scanning electron microscope were used to observe the platelet aggregation induced by MRP. Results Streptococcus suis 2 wild type strain,but not the mutant strain ΔMRP,could induce platelet aggregation. It was MRP-N but not MRP-C that induced platelet aggregation. GPRP,an inhibitor of β2inte-grin receptor,could significantly inhibit the platelet aggregation induced by MRP. Conclusion Streptococ-cus suis 2 MRP induces platelet aggregation through β2integrin receptor pathway.

Objective To construct a mutant strain of Streptococcus suis type 2 05ZYH33 express-ing ABC transporter SSU05 0946 and to study the pathogenicity of ABC transporter SSU05 0946 for better understanding the immune evasion strategies by Streptococcus suis. Methods Genome of the Streptococcus suis type 2 05ZYH33 strain was extracted and used as a template to amplify SSU05 0946 upstream and down-stream homeodomains. Chloramphenicol-resistance gene was amplified by using pSET1 plasmid as the tem-plate. These three amplified fragments were fused and integrated with the thermo-sensitive plasmid pSET4s by using overlap extension PCR. Homologous recombination method was used to construct the mutant strain 05ZYH33Δ0946. Differences between the mutant and wild type strains were evaluated through bacterial ad-hesion assay,whole blood killing assay and challenge test in mice and piglets. Results The mutant strain 05ZYH33Δ0946 was successfully constructed. Results of bacterial adhesion assay demonstrated that SSU05 0946 was not involved in the adherence of Streptococcus suis to human epithelial cells. SSU05 0946 was an ovel anti-phagocytic factor and virulence factor of Streptococcus suis. Conclusion Streptococcus suis type 2 ABC transporter SSU05 0946 is a newly discovered virulence factor of Streptococcus suis, playing an impor-tant role in the evasion of host innate immunity by Streptococcus suis.

Objective To evaluate the difference of Doumas′method and 15 commercial serum total protein ( TP ) methods based on EP9-A3.Methods Serum panels were quantified for TP with Doumas′method and measured in parallel with 15 commercial methods.The linear regression analyses were performed, followed by calculating relative deviation and 95%CI between commercial method and Doumas′method at three different medical decision levels (45 g/L, 60 g/L, 80 g/L).We also calculated relative deviation, 95% limit of agreement ( LoA ) and 95% CI based on classical and improved Bland-Altman method at three different medical decision levels.If both the relative deviation and 95%CI were within 5%, we conside red the commercial serum total protein method was comparable to Doumas′method.Results (1) All assays presented high correlation ( r>0.975, P<0.001) with the Doumas′method.All assays showed that the relative deviations and 95%CIs were within the biological total error goal (5%) at medical decision levels based on regression analysis.(2) Based on classical and improved Bland-Altman method, fourteen of 15 commercial methods showed that the relative deviations and 95%CIs were within +/-5%. Conclusions All commercial assays are comparable to Doumas′method at medical deviation levels.There is no difference between regression analysis and Bland-Altman method for comparison study.

Objective To investigate the in vitro effects of human bone marrow derived mesenchymal stem cells (hBMSC) on Th17 cells of the human peripheral blood.Methods The density gradient centrifugation combined with lymphocyte separation medium was used to isolate hBMSC,which were then cultured.Cytokine IL-17 in the peripheral blood from a healthy person was measured by enzyme-linked immunosorbent assay (ELISA).Proportion of Th17 cells was evaluated by flow cytometry.Results The expression level of IL-17 in spent culture supernatant of the healthy person PBMC and AML hBMSC was (292.32±37.25) pg/ml,and was significantly higher than that of the healthy person PBMC and healthy hBMSC [(169.64±17.47) pg/ml,P ＜ 0.01].There was no significant difference between the expression level of IL-17 in spent culture supernatant of the healthy person PBMC and ALL hBMSC [(159.89±23.71) pg/ml] and the level of the healthy person PBMC and hBMSC.The percentages of Th17 cells of co-culture systems from hBMSC,ALL-hBMSC,and AML-hBMSC and PBMC were (10.13±2.19) ％,(13.77±4.04) ％ and (21.53±5.05) ％,respectively,with the result between AML patients and healthy people being statistically different (P ＜ 0.01).ALL patients and healthy people showed no difference (P ＞ 0.05).Conclusion AML-hBMSC promotes the CD~ T cells to generate Th17 cells,which suggests that the MSC from AML marrow may play a role in the regulation of immune suppression.

Objective To construct a fusion protein to transfect some cell lines that were difficult to be transfected such as neoplastic cells, nerve cells, stem cells. Methods PCR was performed to amplified protein transductions domain(PTD),G4S and streptavidin (Strep).Enzymatic digestion and ligation were used to construct pAYZ-PTD-Strep plasmid. Fusion protein was induced to express by AP5 medium and was isolated by E-tag affinity chromatography. Fusion protein was identified by Western blot. eGFP was trasfected into U937 cells by pAYZ-PTD-Strep. FACS was performed to detect transfection percentage. Results Fusion protein PTD-G4S-Strep was expressed as soluble protein.The concentration of fusion protein was about 0.7 mg/L,and purity was over 90 ％. The protein could carry plasmid into a suspended cell line, U937 cells. The transfection-efficiency of protein was higher than monometer PTD.Conclusion The protein PAYZ-PTD-Strep could carry macromolecules into blood tumor cells,and its biological activity may be expected to develop into a highly efficient and reliable transfection method.

Objective To identify multidrug resistance (MDR) associated cell surface antigen in hematologic neoplasia and to investigate the universality of membrane-relocated expression of this antigen in hematologic neoplasia.Methods The membrane antigen was isolated and precipitated by SDS-PAGE and co-immunoprecipitation (co-IP),then was identified by mass spectrum (MS).Specific siRNA was used to interfere with gene expression,laser confocal microsopy was used to validate the results involved in antigen information.FACS was performed to analyse relocated expression of the antigen in hematologic neoplasia.Results Co-IP and MS show that a nuclear factor PSF was the antigen of 5D12,a leukemia-MDR associated McAb,and this antigen could relocate on HL-60 cell membrane.A series of experiences further confirmed that PSF overexpressed on HL-60 cell membrane compared with HL-60/ADR.The binding percentages of 5D12 to many hematologic tumor cells were observed,HL-60 (78.56±0.76) ％,K562 (26.54±4.42) ％,Nomalwa (38.10±5.11) ％,U937 (64.03±7.96) ％,Jurkat (29.12±5.58) ％,Raji (74.92±3.41) ％,CEM (12.18±3.21) ％.Conclusion Nuclear protein,PSF relocalizes on cell surfaces in hematologic tumor cells and contributes to cell sensitivity.PSF is a potential target of MDR prediction in hematologic neoplasia.

Objective To construct a fusion protein that used for treatment of resistance and palindromia in leukemia and studied its biological activity. Methods IL-3 and LP gene fragments were amplified by PCR. After enzymatic digestion and T4 ligation, the fusion gene was cloned into expression vector pAYZ. The product was purified by exchange chromatography and anti-Etag affinity chromatography. IL3-G4SLP fusion protein was analyzed by SDS-PAGE and Western blot. Protein biological activity was detected by FACS. Results The fusion protein was expressed as soluble protein by E.Coli 16C9. The protein expression level was about 1 mg/L, its purity was over 95 %, and the expression level was about 1 mg/L. The fusion protein can combined specificely with CD123 on leukemia stem cells. Conclusion Fusion protein IL-3-G4S-LP can target on leukemia stem cells and maybe as a potential drug used for treatment of resistance and palindromia in leukemia.

Aim To study the mechanism of synergistic antitumor of EBB and doxorubicin in doxorubicin-resistant MCF-7/ADR breast carcinoma cells.Methods The antitumor activity of doxorubiein alone and its combination with EBB were measured by MTT assay in MCF-7/ADR and MCF-7cells. The rate of doxorubicin-induced apoptosis and the protein and mRNA levels of P-glycoprotein(P-gp) were determined in MCF-7/ADR treated with EBB by flow cytometry (FACS), respectively.Laser scanning confocal microscopy was used to detect the intracellular accumulation of drug in EBB-treated MCF-7 and MCF-7/ADR cells.Results EBB had antitumor effects for MCF-7 and MCF-7/ADR.It could potentiate the antitumor effect of dororubicin with CDI of 0.73 and 0.49 for MCF-7 and MCF-7/ADR,respectively.EBB and doxorubicin acted synergistically in elevating apoptosis of MCF-7/ADR and downregulating the expression of P-gp in a dose-dependent manner in MCF-7/ADR.EBB restored the intracellular accumulation of doxorubicin in MCF-7/ADR cells in a dose-dependent manner.After pretreatment with EBB for 24 h and 48 h,the intracellular accumulation of doxorubicin and Rh123 was obviousely restored in MCF-7/ADR cells compared with control in a time-dependent manner.Conclusion EBB is a potential agent which has strong inhibitory effect on both multidrug resistant cells and their parental cells.EBB can significantly potentiate the antitumor effects of dororubicin in MCF-7/ADR cells by blocking the function of P-glycoprotein and inhibiting the expression of P-glycoprotein.