Analysis and clinical significance of ETV6 rearrangement in myelodysplastic syndromes patients / 中华血液学杂志

<p><b>OBJECTIVE</b>To identify the ETV6 gene rearrangement in patients with myelodysplastic syndromes (MDS) and explore its relationship with prognosis and disease stages.</p><p><b>METHODS</b>ETV6 rearrangement in 58 MDS cases were detected by conventional cytogenetics and Split-signal FISH. RT-PCR was used to detect 9p24-12p13 balance translocation with special designed primers ETV6F1/F2 and JAK2R1/R2. The relationship between ETV6 rearrangement and prognosis and disease staging in MDS patients was analyzed.</p><p><b>RESULTS</b>ETV6 rearrangement were found in 4 (6.9%) of 58 cases, among which ETV6/JAK2 fusion was identified by RT-PCR in 1 (1.7%) case. The mean follow-up duration was 12 months. All 4 patients (100%) with rearrangement transformed into acute leukemia, with a median survival time (MS) of 7 months; while 10 patients (17%) in the non-translocation group transformed to acute leukemia, with a MS of 28 months. In addition, all 4 patients (100%) with rearrangement were in advanced stage of MDS( RAEB), while 17 cases (31.5%) in non-rearrangement group were in that stage.</p><p><b>CONCLUSIONS</b>ETV6 rearrangement has higher expression rate (6.9%), and is closely associated with disease stage and prognosis in MDS.</p>

Preliminary study of multivariable model in predicting response to immunosuppressive therapy in patients with aplastic anemia / 中华血液学杂志

<p><b>OBJECTIVE</b>To evaluate the potential usefulness of a multivariable model in predicting the response to immunosuppressive therapy (IST) in patients with aplastic anemia (AA), and its application to the clinical practice.</p><p><b>METHODS</b>PB T cells subpopulation and BM T cells intracellular IFN-gamma and IL-4 were serially analyzed by flow cytometry (FCM) before and during treatment. HLA-DRB1 * 1501 phenotype was analyzed by PCR-SSP. The predictive potentials of different parameter combinations for clinical responsiveness were statistically assessed.</p><p><b>RESULTS</b>In all evaluated parameters, CD8+ cell intracellular IFN-gamma had the relatively best diagnostic value with sensitivity and specificity of 94.3% and 62.5%, and positive and negative predictive value of 84.6% and 83.3% respectively. Positive CD8+ cell intracellular IFN-gamma plus Tc1/Tc2 < 50 could increase the positive predictive value to 92.3%. A multivariable model consisting of absolute neutrophil count (ANC), BM T cell intracellular IFN-gamma, Tc1/Tc2 ratio and HLA-DRB * 1501 phenotype of the patients was finally established.</p><p><b>CONCLUSION</b>The multivariable model is superior to each of the single parameters in terms of predictive power of IST therapeutic outcome, and its higher accuracy and the clinical application make it potentially useful in practice.</p>

Activation of platelet-neutrophil mediated by platelet-activating factor / 中国实验血液学杂志

To investigate the pathophysiological mechanisms for platelet-neutrophils cross talk mediated by platelet-activating factor (PAF) and to lay a foundation for clinical application, ginkgolides B (GB), a PAF receptor antagonist, was added in the whole blood to block the effects of PAF on activation of platelet-neutrophil; PAF and ADP were respectively added in the whole blood to monitor the expression of CD62P on platelet by flow cytometry; PAF and ADP were added in the whole blood to monitor the expression of CD11b on neutrophil by flow cytometry; PAF and ADP were added in the whole blood to monitor the platelet-leucocyte aggregates (PLA) which were PLA in the total leucocyte population (PLA/L) and the mean fluorescence intensity (MFI) of CD42b. Outcomes were analyzed by t-test, and the differences were statistically significant (P < 0.05). The results showed that the expression of CD62P on platelats, the expression of CD11b on neutrophils and PLA formation were all increased by PAF and ADP; the PAF receptor antagonists (GB) could obviously inhibit the expression of CD62P, CD11b and PLA formation induced by PAF, but could not completely inhibit the activation of platelet and neutrophil, and the platelet-neutrophil cross talk; GB could inhibit the expression of CD62P and CD11b induced by ADP, but could not conpletely inhibit the activation of platelet and neutrophli; GB could not obviously inhibit the platelet-leucocyte aggregates mediated by ADP. It is concluded that the multiligand-receptor systems involved in PLA formation and platelet-netrophils cross talk seem to be regulated by complex mechanisms; the PAF receptor antagonists (GB) obviously inhibit the effect of PAF, and may be widely utilized in the therapy of thrombosis and inflammation.

Function of Delta4 gene and its effects on 32D cell differentiation / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Notch activation leads to transcriptional suppression of lineage-specific genes, inhibiting differentiation in response to inductive signals. The Notch signal system contains three parts: Notch molecules, Notch ligands and effectors. Delta4 is a newly-discovered Notch ligand which has received the attention of few detailed studies. This study sought to explore the biological function of Delta4 and observe its effects on 32D cell differentiation.</p><p><b>METHODS</b>Delta4-expressing vector pTracer.CMV.Delta4.FLAG was constructed using molecular biological techniques. CHO cells stably transfected with pTracer.CMV.Delta4.FLAG were confirmed to have a Delta4 protein band via Western blotting. High-expression Delta4-CHO clones were selected for the following functional studies. Notch1-CHO and Notch2-CHO were used as host cells. After transiently transfecting with transition protein 1 (TP1), Delta4 activity was compared in both cell lines by means of luciferase analysis. CHO cells were incubated with Notch1-32D cells that had been transfected with Notch1 and were observed for granulocyte colony-stimulating factor (G-CSF)-induced differentiation. Jagged2-CHO and Delta4-CHO cells transfected with the Notch ligands Jagged2 and Delta4, respectively, were incubated with Notch1-32D cells to observed inhibition of Notch on G-CSF-induced differentiation.</p><p><b>RESULTS</b>The vector pTracer.CMV.Delta4.FLAG was constructed successfully. CHO cells were stably transfected with the vector pTracer.CMV.Delta4.FLAG. Two CHO cell lines expressing Delta4 at high levels were selected for use in the study. Delta4 was found to induce signal activity via both Notch1 and Notch2 and the induction of signaling activity was stronger in Notch2 cells than in Notch1 cells. Compared with other Notch ligands, Delta4 was slightly weaker than Jagged2, but stronger than Delta1 and Jagged1 in terms of Notch1 ligands. In terms of Notch2, Delta4 had a strong signaling activity, but was weaker than Delta1, Jagged1, and Jagged2. Jagged2 could inhibit Notch1-32D cell differentiation induced by G-CSF, but Delta4 could not.</p><p><b>CONCLUSIONS</b>Delta4 induces both Notch1 and Notch2 activity and is a ligand for both of them. The effect of Delta4 is stronger on Notch2 than that on Notch1. Jagged2 can inhibit Notch1-32D cell differentiation induced by G-CSF, but Delta4 cannot.</p>