With the increasing information on the number, quality, and characteristics of hematopoietic stem cells (HSC) in umbilical cord and placental blood, this material has been found to be efficacious as an alternative source of HSC for transplantation in children. In this study, we sought to define the optimal conditions for ex vivo expansion of cord blood (CB) stem cells. These conditions include: the combinations and concentrations of hematopoietic growth factors (stem cell factor [SCF], granulocyte-macrophage colony-stimulating factor [GM-CSF], interleukin [IL]-3, thrombopoietin [Tpo], IL-6 and Fms-like tyrosine kinase 3 ligand [Flt-3L]), the duration of culture, and the effect of serum supplementation. In this study, 2 protocols were applied for ex vivo expansion of CB stem cells. In protocol I, 20 CB samples were expanded in a static, serum-added, liquid culture for 7 and 11 days using 5 cytokine cocktails. In protocol II, 10 CB samples were expanded for 7 days using cytokines of cocktail 1, with and without IL-6 and Flt-3L, in serum-added and serum-free culture media. This protocol was intended to verify the effect of IL-6, Flt-3L, and the role of serum supplementation in short-term liquid culture. From the present study, it can be concluded that cocktail 1 is the cocktail of choice for ex vivo expansion of CB stem cells in serum-free, liquid culture expanded for 7 days. We can also conclude that culture expanded for 7 days is better than 11 days, as the fold expansion of CD34+ cells was not significantly increased or even decreased in some of the cocktails used. Moreover, the percent of CD95+ cells (apoptotic cells) was significantly increased on day 11 compared to day 7 in the cocktails tested.

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Apoptosis deregulation is important for cancer development, chemotherapy response, and prognosis. Survivin and X-linked inhibitor of apoptosis protein (XIAP) are 2 members of the inhibitor of apoptosis proteins family (IAP). We used semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) to determine the levels of expression of survivin and XIAP in 30 patients with de novo acute myeloid leukemia (AML) and 20 age- and sex-matched healthy volunteers. Survivin and XIAP overexpression were detected in 36.7% and 43.3% of cases, respectively. Patients with overexpression of either survivin or XIAP showed unfavorable response to chemotherapy in 81.2% and 91.7%, respectively. Also, these cases showed shorter median survival time (30 days) compared to patients with normal expression of either survivin or XIAP (150 days and 180 days). Patients with overexpression of both survivin and XIAP showed unfavorable response to induction therapy in 100% of the patients and the shortest median survival (30 days). These findings suggest that survivin and XIAP may have a role in leukemogenesis and provide prognostic information.

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Background and Objectives: In cases of β-thalassemia major, apoptosis appears to be greatly enhanced in the early-stage erythroid precursors in the bone marrow leading to ineffective erythropoiesis. L-Carnitine is found to strongly reduce apoptosis in different diseases. We investigated the effect of oral L-carnitine therapy on apoptosis in thalassemia major patients. Methods: Eighteen thalassemia major patients with a mean age of 12.2 ± 6.6 years were included. Detection of apoptosis was done by photometric enzyme immunoassay (ELISA) and agarose gel electrophoresis before and after 6 months of oral therapy with L-carnitine (50 mg/kg/day). Results: A significant decrease of apoptosis frequency in the erythroid precursors in the bone marrow of studied cases was noted after therapy. The quantity of nucleosomes measured by ELISA dropped from 3.65 ± 1.338 to 1.60 ± 0.65 after therapy (p = 0.005). A positive ladder pattern reflecting apoptosis on agarose gel electrophoresis was detected in 88.9% of cases prior to treatment versus 16.7% after therapy (p = 0.006). Patients also had a significant decrease in the frequency of transfusions and increase in the pre-transfusion hemoglobin levels after therapy. Conclusion:L-Carnitine seems to be a good modulator of apoptotic processes in thalassemic patients leading to a decreased frequency of programmed erythroblast death and general improvement of the disease condition.