Alternative donor HSCT for 109 children with acquired severe aplastic anemia: a single center retrospective analysis / 中华血液学杂志

Objective: To investigate the efficacy of alternative donor (AD) in the treatment of aplastic anemia (AA) in children. Methods: The clinical data of AA children who received AD HSCT in our center from Apr. 2010 to Dec. 2016 were retrospectively analyzed. The overall survival (OS) rate, implant success rate, incidence of acute and chronic graft-versus-host disease (GVHD) were statistically analyzed. Results: A total of 109 children with acquired AA, including 64 severe AA (SAA) , 32 very severe AA (VSAA) and 13 transfusion dependent non-severe AA (NSAA) , were recruited in this retrospective AD HSCT study, the median age was 6 (0.8-18) years old. Of them, 44 patients with 10/10 matched unrelated donor (MUD) , 44 patients with mismatched unrelated donor (MMUD) and 21 patients with mismatched related donor (MMRD) . All patients did not receive ATG before HSCT and the active infection was excluded. Except 3 patients suffered from a second graft failure (2 of them rescued by second HSCT) , 106/109 (97.2%) were engrafted with neutrophil and platelet recovery occurring at a median of 13 days (range, 9-19) and 16 days (range, 10-81) post-transplant. Until day 100 post transplantation, the incidence was 74.3% (81/109) for acute GVHD (aGVHD) and 39.4% (43/109) for grade Ⅱ-Ⅳ aGVHD, 30.7% (31/101) and 9.9% (10/101) for overall chronic GVHD (cGVHD) and moderate cGVHD, respectively, and nobody developed an extend cGVHD. After median follow up of 39 (0.7-103) months for all patients, 13 of 109 patients died. The estimated 5-year overall survival (OS) of the entire cohort was 88.1% (95%CI 81.1%-91.4%) with no difference among the MUD, MMUD and MMRD cohort (93.2%, 84.1% and 85.7%, respectively, P=0.361) . Conclusion: These excellent outcomes suggest that unmanipulated AD PBSC is a good HSCT source for children with SAA. It's reasonable to consider AD HSCT as first line therapy for SAA children without matched sibling donor. Better strategies are required to prevent GVHD.

The cultivation and identification of tumor stem cells from neuroblastoma derived tumor spheres / 癌症

<p><b>BACKGROUND AND OBJECTIVE</b>Since the proposal of the tumor stem cell hypothesis, considerable interest has been devoted to the isolation and purification of tumor stem cells. Tumor stem cell enrichment from primary tumor derived cell spheres has been demonstrated in specific, serum-free media. This goal of this study is to establish a method of cultivating floating tumor spheres from neuroblastoma cells and to confirm that neuroblastoma spheres are rich in tumor stem cells.</p><p><b>METHODS</b>Bone marrow aspirates were obtained from pediatric patients diagnosed with stage IV neuroblastoma. Primary tumor cells were isolated and cultivated in serum-free, stem cell-selective medium. Single sphere-forming cells were cultivated under serum-free conditions; their cloning efficiency and monoclonal tumor sphere formation rates were calculated. The expression of stem cell marker genes Oct-4 and Bmi-1 was detected by RT-PCR in sphere-forming cells and parental neurolastoma cells. Sphere-forming cells were injected into the armpit of nude mice with subsequent assessment for tumor growth. Sphere-forming cells were cultivated in differentiation medium containing 5 μmol/L 13-cis retinoic acid; changes in cell morphology were observed.</p><p><b>RESULTS</b>Neuroblastoma cells formed non-adherent neurospheres under serum-free, stem cell-selective conditions after a period of 4 to 6 days. A single cell dissociated from a neurosphere could reform a monoclonal sphere; cloning efficiency and monoclonal sphere formation rates were 55.3% and 26.3%, respectively. RT-PCR results revealed heightened tumor sphere expression of Oct-4 and Bmi-1 as compared with parental tumor cells. Fourteen days after injection of 10(4) sphere-forming cells into nude mice, a neuroblastoma xenograft formed. Treatment of sphere-forming cells with 13-cis retinoic acid induced a gradual differentiation to neuronal cell morphology.</p><p><b>CONCLUSIONS</b>Neuroblastoma derived tumor spheres enrich tumor stem cells and the cultivation of primary neuroblastoma cells in serum-free, stem cell-selective medium is an effective method to dissociate and purify tumor stem cells in vitro.</p>