Objective To explore the possible relationship between alteration of cell cycle and JAK/STAT3 signal transduction pathway inhibition induced by arsenic trioxide (As_2O_3,) in myeloma cell lines U266 and RPMI8226 in vitro. Methods Multiple myeloma cell lines U266 and RPMI8226 were used as in vitro models. The influence of AS_2O_3 on myeloma cells were evaluated by MTT assay and flow cytometry. Meanwhile, methylation specific PCR and Western blotting were employed to detect the methylation status of gene SOCS-1 and protein expression level of P-STAT3 in these cells after AS_2O_3 treatment. Results AS_2O_3 significantly inhibited the growth of U266 and RPMI8226 cells in a dose-dependent manner. Furthermore, cell cycle was arrested at G0/G1 phase with inhibition of protein expression level of P-STAT3 and SOCS-1 gene demethylation after exposure to As_2O_3 for 72 h( r = 0. 85, P < 0.05). Conclusion AS_2O_3 could induce the alteration of cell cycle which might be related to JAK/STAT3 signal transduction pathway inhibition and SOCS-1 demethylation in myeloma cell lines. The study puts forward a new idea of AS_2 O_3 treatment in multiple myeloma.

Objective To evaluate the efficacy of pegaspargase (PEG-ASP) combined with GEMOX regimen for the treatment of extranodal natural killer (NK) / T-cell lymphoma (ENKL),and to observe the changes of coagulation function.Methods 35 patients with histologically confirmed ENKL were enrolled from January 2010 to December 2014.All patients received 180 cycles of PEG-ASP combined with GEMOX chemotherapy and the efficacies were observed.The coagulation items such as prothrombin time (PT),activated partial thromboplastin time (APTT),fibrinogen (Fbg) and international normalized ratio (INR) were tested respectively on day 1st,day 8th and day 14th of every treatment cycle.Results Among 35 patients,11 patients (31.43 ％) were in stage Ⅰ-Ⅱ,and 24 patients (68.57 ％) were in stage Ⅲ-Ⅳ.All patients were subjected to 180 cycles of PEG-ASP combined with GEMOX chemotherapy,and each case was estimated to receive 6 cycles.The overall response (CR+PR) rate (ORR) was 71.43 ％ (25/35),the ORR was 81.82 ％ (9/11) in stage Ⅰ-Ⅱ group,and 66.67 ％ (16/24) in stage Ⅲ-Ⅳ group.The increased PT and APTT and decreased Fbg were observed on day 8th of the chemotherapy.The increased APTT and decreased Fbg were still observed on day 14th of the chemotherapy.Compared the data of patients one day before chemotherapy with healthy persons,the changes had statistical significance (P ＜ 0.05).Conclusions PEG-ASP combined with GEMOX regimen in the treatment of ENKL is safer and more effective compared with traditional chemotherapy,but the abnormal alternations of coagulation might be common during therapy.Dealing with the bleeding risk and supplement with plasma,PPSB or Fbg in time should be necessary.

In order to investigate peptide mimics of carbohydrate blood group A antigen, a phage display 12-mer peptide library was screened with a monoclonal antibody against blood group A antigen, NaM87-1F6. The antibody-binding properties of the selected phage peptides were evaluated by phage ELISA and phage capture assay. The peptides were co-expressed as glutathione S-transferase (GST) fusion proteins. RBC agglutination inhibition assay was performed to assess the natural blood group A antigen-mimicking ability of the fusion proteins. The results showed that seven phage clones selected bound to NaM87-1F6 specifically, among which, 6 clones bore the same peptide sequence, EYWYCGMNRTGC and another harbored a different one QIWYERTLPFTF. The two peptides were successfully expressed at the N terminal of GST protein. Both of the fusion proteins inhibited the RBC agglutination mediated by anti-A serum in a concentration-dependent manner. These results suggested that the fusion proteins based on the selected peptides could mimic the blood group A antigen and might be used as anti-A antibody-adsorbing materials when immunoabsorption was applied in ABO incompatible transplantation.
Adsorption ; Bacteriophages ; Blood Group Antigens/*chemistry ; Enzyme-Linked Immunosorbent Assay ; Epitopes/chemistry ; Glutathione Transferase/metabolism ; Peptide Library ; Peptides/*chemistry ; Protein Structure, Tertiary ; Recombinant Fusion Proteins/chemistry

Objective To investigate the effects of arsenic trioxide (AS2O3)on SOCS-1 gene methylation and expression of P-STAT3 in multiple myeloma (MM) cells.Methods MM cell lines U266 and CZ-1 were used as in vitro models.Methylation status of SOCS-1 gene was detected by the methylation specific PCR (MSP)while P-STAT3 protein expression was determined by Western blotting assay before and after AS2O3 treatment.Meanwhile growth inhibition and apoptosis of MM cells were determined by flow cytometry.Results Hypermethylation of SOCS-1 gene was observed in each MM cell line compared with wide type.After exposure to AS2O3,it was shown that SOCS-1 gene was demethylated obviously,meanwhile the expression level of P-STAT3 protein and cell proliferation was inhibited significantly in each cell line.The apoptosis rate was increased.When U266 and CZ-1 were treated with AS2O3 of 0,0.5,1.0,2.0 μmol/L respectively,the total cell apoptosisis ratio of U266 was 0.06％,0.56％,48.96％,61.07％ (X2 =9.19,P ＜ 0.05); and the total cell apoptosisis ratio of CZ-1 was 4.2％,,40.3％,,47.72％,,68.49％ (X2 =8.96,P ＜0.05 ).Conclusion AS2O3 could inhibit JAK/STAT signal transduction pathway by inducing SOCS-1 gene demethylation in MM cells which might be related to cell apoptosis.

In order to investigate peptide mimics of carbohydrate blood group A antigen, a phage display 12-met peptide library was screened with a monoclonal antibody against blood group A antigen, NaM87-1F6. The antibody-binding properties of the selected phage peptides were evaluated by phage ELISA and phage capture assay. The peptides were co-expressed as glutathione S-transferase (GST) fusion proteins. RBC agglutination inhibition assay was performed to assess the natural blood group A antigen-mimicking ability of the fusion proteins. The results showed that seven phage clones selected bound to NaM87-1F6 specifically, among which, 6 clones bore the same peptide sequence, EYWYCGMNRTGC and another harbored a different one QIWYERTLPFrF. The two peptides were successfully expressed at the N terminal of GST protein. Both of the fusion proteins inhibited the RBC agglutination mediated by anti-A serum in a concentration-dependent manner. These results suggested that the fusion proteins based on the selected peptides could mimic the blood group A an- tigen and might be used as anti-A antibody-adsorbing materials when immunoabsorption was applied in ABO incompatible transplantation.

The effect of cyclin-dependent kinase inhibitors Cip1/Wafl (p21) on regulatory expression of survivin transcription in human hepatocellular carcinoma cell HepG2 was observed and the related mechanisms explored. Doxorubicin (DOX) was used to treat HepG2. Eukaryotic vector pEGFP-C2-p21 was transfected into HepG2 by lipofectamine and positive clones were screened out by G418. The mRNA expression of p21 and survivin was detected by real-time fluorescent quantitative polymerase chain reaction (RQ-PCR). Flow cytometry was used to examine the cell cycle, and reverse transcription polymerase chain reaction (RT-PCR) was used to measure the levels of E2F-1 and p300. The results showed that: (1) After treatment with DOX, the expression of p21 was increased, whereas that of survivin was reduced during 24h of treatment; (2) After transfection of pEGFP-C2-p21 into HepG2, p21 level was significantly enhanced to 2100.11-folds or 980.89-folds in comparison to HepG2 or HepG2-C2 group, and survivin level was markedly down-regulated to 0.54% or 0.59% relative to the control groups; (3) Overexpressed p21 resulted in G1/G0 phase arrest (F=31.59,P<0.01), meanwhile E2F-1 mRNA and p300 mRNA were reduced as compared with those of controls (FE2F-1=125.28,P<0.05;Fp300=46.01,P<0.01). It was suggested that p21 could be a potential mediator of survivin suppression at transcription level in HepG2 cell, which might be through the block at G1/G0 phase and down-regulation of transcription factors E2F-1 and p300.