Human mesenchymal stem cells from chorionic villi and amniotic fluid are not susceptible to transformation after extensive in vitro expansion.

Mesenchymal stem cells (MSCs) are promising candidates for cell therapy and tissue engineering. Increasing evidence suggests that MSCs isolated from fetal tissues are more plastic and grow faster than adult MSCs. In this study, we characterized human mesenchymal progenitor cells from chorionic villi (CV) and amniotic fluid (AF) isolated during the first and second trimesters, respectively, and compared them with adult bone marrow-derived MSCs (BM). We evaluated 10 CV, 10 AF, and 6 BM samples expanded until the MSCs reached senescence. We used discarded cells from prenatal analyses for all the experiments. To evaluate the replicative stability of these cells, we studied the telomerase activity, hTERT gene transcription, and telomere length in these cells. Spontaneous chromosomal alterations were excluded by cytogenetic analysis. We studied the expression of c-myc and p53, tumor-associated genes, at different passage in culture and the capacity of these cells to grow in an anchorage-independent manner by using soft agar assay. We isolated homogeneous populations of spindle-shaped CV, AF, and BM cells expressing mesenchymal immunophenotypic markers throughout the period of expansion. CV cells achieved 14 ± 0.9 logs of expansion in 118 days and AF cells achieved 21 ± 0.9 logs in 118 days, while BM cells achieved 11 × 0.4 logs in 84 days. Despite their high proliferation capacity, fetal MSCs showed no telomerase activity, no hTERT and c-myc transcriptions, and maintained long, stable telomeres. A constant expression level of p53 and a normal karyotype were preserved throughout long-term expansion, suggesting the safety of fetal MSCs. In conclusion, our results indicate that fetal MSCs could be an alternative, more accessible resource for cell therapy and regenerative medicine

Feasibility and Outcome of a Phase II Study of Intensive Induction Chemotherapy in 91 Elderly Patients with AML Evaluated Using a Simplified Multidimensional Geriatric Assessment

Introduction: We prospectively tested in a phase II study high-dose aracytin and idarubicin plus amifostine as induction regimen in 149 patients with acute myeloid leukaemia (AML) aged ≥ 60 years, evaluated by a simplified multidimensional geriatric assessment (MGA). Methods: Ninety-one fully or partially fit patients (61%) were allocated to intensive chemotherapy and 58 (39%) frail patients to best supportive care (BSC). Intensively treated patients, showing early death and complete response (CR) rate respectively of 5.5% and 73.6%, received 61 consolidations, followed by autologous transplant (ASCT), stem cell transplantation (SCT) or gemtuzumab ozogamicin, depending on mobilization outcome and donor availability. Results: The 8-year overall survival (OS) of these patients was 20.4%, with median duration of 11.4 months significantly superior to the 1.5 months of BSC arm (p < 0.001). Hyperleukocytosis and cytogenetics were predictors of survival with a relative risk of 1.8 in patients with poor karyotype without hyperleukocytosis (p = 0.02) and 3 in those with hyperleukocytosis (≥ 50,000/μl) (p = 0.002). Conclusion: MGA allowed tailored post-consolidation in 53.8% of patients after high-dose aracytin induction, with long-term survival doubling that reported in the literature after standard-dose cytarabine regimens

Variant Philadelphia translocations: Molecular-cytogenetic characterization and prognostic influence on frontline imatinib therapy, a GIMEMA working party on CML analysis

Variant Philadelphia (Ph) chromosome translocations have been reported in 5%-10% of patients with newly diagnosed chronic myeloid leukemia (CML). Variant translocations may involve one or more chromosomes in addition to 9 and 22, and can be generated by 2 different mechanisms, 1-step and 2-step rearrangements, as revealed by fluorescence in situ hybridization. The prognostic significance of the occurrence of variant translocations has been discussed in previous studies. The European LeukemiaNet recommendations do not provide a "warning" for patients with variant translocations, but there is limited information about their outcome after therapy with tyrosine kinase inhibitors. To identify the role of variant translocations in early chronic phase (CP) CML patients treated with imatinib mesylate, we performed an analysis in a large series of 559 patients enrolled in 3 prospective imatinib trials of the Gruppo ItalianoMalattie EMatologiche dell'Adulto (GIMEMA) Working Party on CML. Variant translocations occurred in 30 patients (5%). Our data show that the presence of variant translocations has no impact on the cytogenetic and molecular response or on outcome, regardless of the involvement of different mechanisms, the number of involved chromosomes, or the presence of deletions. Therefore, we suggest that patients with variant translocations do not constitute a "warning" category in the imatinib era. This study is registered at www.clinicaltrials.gov as NCT00514488 and NCT00510926. © 2011 by The American Society of Hematology