Zhizhe Chen

Bone marrow-derived mesenchymal stem cells overexpressing MiR-21 efficiently repair myocardial damage in rats

Objective We investigated the ability of bone marrow derived mesenchymal stem cells (BMSCs) overexpressing microRNA-21 (miR-21) to repair cardiac damage induced by anthracyclines in rats. Methods Sprague-Dawley (SD) rats of 2~3 weeks old were selected to isolate and culture BMSCs. A lentivirus harboring pLVX-miR-21 was generated and transfected into rat BMSCs. The rats were assigned into an untreated negative control group, and groups injected with adriamycin alone or with adriamycin followed by BMSCs, pLVX-BMSCs or pLVX-miR-21-BMSCs (n = 10 each). Proliferation and migration of cells were detected by cholecystokinin-8 (CCK- 8) and transwell. MiR-21 expression, mRNA expressions of B cell lymphoma 2 (Bcl2), BAX (BCL-2-associated X protein) and vascular endothelial growth factor (VEGF) were tested by qRT-PCR. Western blotting was applied to detect protein expressions of Bcl-2, Bax and VEGF. Results Using CCK- 8 and transwell assays, we found that pLVX-miR-21-BMSCs, which overexpressed miR-21, exhibited greater proliferation and migration than untransfected BMSCs or pLVX-BMSCs. Ultrasonic cardiograms and immunohistochemical analysis demonstrated that among the five groups, the pLVX-miR-21-BMSC group exhibited the most improved heart function and enhanced angiogenesis. Moreover, the pLVX-miR-21-BMSC group showed enhanced expression of Bcl-2, VEGF and Cx43 and reduced expression of Bax, BNP and troponin T. Conclusion These findings suggest miR-21 overexpression enhanced the proliferation, invasiveness and differentiation of BMSCs as well as expression of key factors (Bcl-2, VEGF and Bax) essential for repairing the cardiac damage induced by anthracyclines and restoring heart function.

A 5-day cytoreductive chemotherapy followed by haplo-identical hsct (FA5-BUCY) as a tumor-ablative regimen improved the survival of patients with advanced hematological malignancies

Haplo-HSCT has been used when HLA-matched siblings are not available. Conditioning regimens aim to reduce tumor burden prior to HSCT and provide sufficient immunoablation. We report the outcome of haplo-HSCT in 63 consecutive patients from 2/2013 to 12/2015 (19 females/44 males) with high-risk or relapsed/refractory hematological malignancies (n=29-AML; 8-sAML; 19-ALL; 5-advanced-MDS; 2-CML-BC). Median age was 20 years (range: 1.1-49). Twenty-one patients achieved remission prior to transplant, while 42 did not. Patients received FA5-BUCY, i.e., 5-day salvage chemotherapy (Fludarabine/Ara-C) and conditioning (Busulfan/Cyclophosphamide). GvHD prophylaxis included ATG, CsA, MMF and short-term MTX. All patients received stem cells from bone marrow and peripheral blood, and achieved successful engraftment, except two who died before. With a median follow-up of 269 days (120-1081), 42/63 patients are still alive and disease-free. Two-year OS and RFS were similar in patients not in remission and in those in complete remission (61.3% vs 56.3%, p=0.88; 58.3% vs 56.3%, p=0.991). Non-relapse mortality and relapse incidence were 22.2% and 11.1%, respectively. Severe acute-GvHD occurred in 4/63 patients. Transplant-related mortality was low at day+100 (17.5%) and for the entire study period (20.6%). Unexpectedly, few patients experienced mild-to-moderate toxicity, and main causes of death were infection and GvHD. BM blast counts, age, and donor-recipient gender-pairs did not affect the outcome. Less chemotherapy cycles prior to HSCT might result in more favorable outcome. Thus, haplo-HSCT with FA5-BUCY appears promising for advanced disease, especially when TBI and amsacrine, used for FLAMSA, are not available and in pediatric patients for whom TBI is not recommended.

Lymph Node Flow Cytometry as a Prompt Recognition of Ultra Early Onset PTLD: A Successful Case of Rituximab Treatment.

Ultra early posttransplantation lymphoproliferative disorder (PTLD) is a rare and fatal complication after hematopoietic stem cell transplantation (HSCT). Here we report, by lymph node (LN) flowcytometry, that we early recognized ultra early PTLD after an HLA-matched sibling allo-HSCT followed by a successful treatment with anti-CD20 antibody (rituximab) in a patient in progress disease for angioimmunoblastic T-cell lymphoma (AITL). The patient was conditioned with a reduced intensity conditioning (RIC) regimen. One week after transplantation, the patient developed high fever, generalized fatigue, high Epstein-Barr virus (EBV) load, and LN enlargement. An LN lymphocyte suspension and peripheral blood flowcytometry was performed to find majority of LN lymphocytes highly expressed CD20. By highly suspicious PTLD, 4 doses of rituximab (375 mg/m2 qw) were given immediately followed by reducing and withdrawing immunosuppressant reagent. PTLD was later confirmed by pathology. The patient had good response to rituximab, showing absence of fever, reduction in LN size, and no detectable EBV-DNA. Twenty months after HSCT, the patient remains well without evidence of AITL and PTLD. The current report is one of the earliest cases of PTLD after HSCT. Taken together, by LN flowcytometry as a prompt recognition, rituximab can be an effective preemptive therapy for ultra early developed PTLD.

In vitro effects of reprogramming factors on the expressions of pluripotent genes and CD34 gene in human acute promyelocytic leukemia HL-60 cells

OBJECTIVE Our study aims to explore the in vitro effects of reprogramming factors on the expressions of pluripotent genes and CD34 gene in HL-60 cells. METHODS According to the construction of lentiviral vector LV-OSCK of reprogramming factors (Oct-4, Sox2, Klf4, c-Myc), 293T cells were transfected to detect virus titer. The endogenous pluripotent genes (Oct4, SOX2, c-Myc and Klf4) and CD34 mRNA and protein expressions were detected by AP staining, immunofluorescence staining, qRT-PCR and flow cytometry. RESULTS Expressions of Oct4, SOX2, c-Myc and Klf4 were 0.220±0.013, 0.186±0.009, 0.287±0.015 and 0.153±0.007. These levels were significantly higher in the experimental group than the control and blank groups. CD34 protein expression in the experimental group was also discovered to be significantly higher than the other two groups. CONCLUSION The reprogramming factors could increase the expressions of pluripotent genes and CD34 gene in HL-60 cells.

The Construction and Identification of Induced Pluripotent Stem Cells Derived from Acute Myelogenous Leukemia Cells

Objective: The present study aimed to establish an induced pluripotent stem cell (iPSC) line from acute myelogenous leukemia (AML) cells in vitro and identify their biological characteristics. Methods: Cells from the AML-infiltrated skin from an M6 patient were infected with a lentivirus carrying OCT4, SOX2, KLF4 and C-MYC to induce iPSCs. The characteristics of the iPSCs were confirmed by alkaline phosphatase (ALP) staining. The proliferation ability of iPSCs was detected with a CCK-8 assay. The expression of pluripotency markers was measured by immunostaining, and the expression of stem cell-related genes was detected by qRT-PCR; distortion during the induction process was detected by karyotype analysis; the differentiation potential of iPSCs was determined by embryoid body-formation and teratoma-formation assays. ALP staining confirmed that these cells exhibited positive staining and had the characteristics of iPSCs. Results: The CCK-8 assay showed that the iPSCs had the ability to proliferate. Immunostaining demonstrated that iPSC clones showed positive expression of NANOG, SSEA-3, SSEA-4, TRA-1-60 and TRA-1-81. qRT-PCR results revealed that the mRNA expression of Nanog, Lin28, Cripto, FOX3, DNMT3b, DPPA2, and DPPA4 significantly increased in iPSCs. Karyotype analysis found no chromosome aberration in the iPSCs. The results of the embryoid body-formation and teratoma-formation assays indicated that the iPSCs had the potential to differentiate into all three germ layers. Conclusion: Our study provided evidence that an iPSC line derived from AML cells was successfully established.

A novel nonradioactive CFDA assay to monitor the cellular immune response in myeloid leukemia.

BACKGROUND Donor lymphocyte transfusion (DLT) may induce the graft-versus-leukemia (GVL) effect for patients with AML relapsed after transplant. However, AML is a highly diverse disease and the limited overall efficacy of DLT in clinical practice emphasizes the importance of identifying a specific subgroup of patients who might benefit from this treatment approach. OBJECTIVE To monitor the cellular immune response after DLT, we developed an active specific immunization strategy using in vitro generated AML-trained T cells to induce a highly specific antileukemic T-cell response and thus established a novel nonradioactive assay system to assess the antileukemia immunity by flow cytometry, correlated with [3H]-thymidine uptake. METHODS The myeloid blasts derived from five patients with AML relapsed post-allogeneic hematopoietic stem cell transplantation (allo-HSCT) were first labeled with CFDA (5,6-carboxyfluorescein diacetate succinimidyl ester). To analyze the growth inhibitory potential of the donor T cells trained by AML progenitor cells, the myeloid blasts were induced to proliferate by means of a cytokine cocktail (50ng/mL of SCF; 25ng/mL of IL-3; 100ng/mL of GM-CSF; 100ng/mL of G-CSF; 2U/mL of EPO; 0.47g/L of transferrin; and 5×10(-5)mmol/L of 2-ME). The T cell mediated growth inhibitory potential was detected after 5 days by flow cytometry and correlated with [3H]-thymidine uptake. The simultaneous use of TO-PRO-dye and calibrate beads allowed not only the cell viability to be known but also allowed quantification of the effector function. RESULTS Here, we applied a CFDA dye to track the proliferation and expansion of AML blasts in response to the cytokine cocktail in vitro. AML-trained T cells, expressed high levels of the activation markers CD25 and CD69, and were generated to recognize the leukemic progenitor cells and inhibit cytokine-induced leukemic cell proliferation, which is an active specific immunization strategy circumventing the identification of leukemia-associated antigens. The capability of proliferation inhibition of AML-trained T cells evaluated with our nonradioactive, CFDA-based assay provided comparable results with the classic [3H]-thymidine assay with an even lower ratio of effector to target cells. CONCLUSION Taken together, the novel, nonradioactive, CFDA-based assay was a robust tool to monitor the antileukemic immune response after DLT in myeloid leukemias.