Mesenchymal stem cells transfer mitochondria to the cells with virtually no mitochondrial function but not with pathogenic mtDNA mutations.

It has been reported that human mesenchymal stem cells (MSCs) can transfer mitochondria to the cells with severely compromised mitochondrial function. We tested whether the reported intercellular mitochondrial transfer could be replicated in different types of cells or under different experimental conditions, and tried to elucidate possible mechanism. Using biochemical selection methods, we found exponentially growing cells in restrictive media (uridine(-) and bromodeoxyuridine [BrdU](+)) during the coculture of MSCs (uridine-independent and BrdU-sensitive) and 143B-derived cells with severe mitochondrial dysfunction induced by either long-term ethidium bromide treatment or short-term rhodamine 6G (R6G) treatment (uridine-dependent but BrdU-resistant).

Hypoxia inhibits the SDF-1-dependent migration of human leukemic cell line HL-60 via blocking of Akt activation.

Hypoxia is known to regulate the expression of genes involved in the migration of various cell types. Although many studies have shown that hypoxia increases cell migration, it still remains unclear whether hypoxia could modulate the stromal cell derived factor-1 (SDF-1)-dependent migration of leukemic cell. Herein, we demonstrated that the SDF-1-dependent migration of HL-60, was reduced under hypoxia with no comparable decrease of CXC-type chemokine receptor CXCR4, a cognate receptor for SDF-1.

CNS recurrence following CD34+ peripheral blood stem cell transplantation in stage 4 neuroblastoma.

We report here central nervous system (CNS) recurrence in neuroblastoma (NBL) after CD34(+) peripheral blood stem cell transplantation (PBSCT). Fifteen stage 4 NBL patients underwent CD34(+) transplantation with myeloablative chemotherapy consisting of carboplatin, etoposide, and melphalan. There were three primary site recurrences and five distant metastases including four brain metastases (two isolated CNS recurrences) at 4-7 months after CD34(+) transplantation.

Co-culture of human CD34+ cells with mesenchymal stem cells increases the survival of CD34+ cells against the 5-aza-deoxycytidine- or trichostatin A-induced cell death.

It has been suggested that epigenetic regulation plays an important role in maintaining the stemness and lineage differentiation of hematopoietic stem cells (HSCs), 5-aza-deoxycytidine (aza-D) and Trichostatin A (TSA) being candidate additives for HSC ex vivo expansion. Although they have potent activity to maintain the stemness, they can also cause serious cell death. This study examined the effects of mesenchymal stem cells (MSCs) on the maintenance of CD34+ cells driven by aza-D and TSA in culture with the combined cytokines of thrombopoietin, flt-3 ligand, stem cell factor, interleukin-3, and interleukin-6.

In vitro generation of functional dendritic cells from human umbilical cord blood CD34+ cells by a 2-step culture method.

Dendritic cells (DCs) are the most potent antigen-presenting cells in terms of initiating primary T-cell-dependent immune responses. We devised a 2-step culture method for obtaining sufficient numbers of functional DCs from umbilical cord blood (CB) CD34+ cells. In the first step, CB CD34+ cells were expanded by stimulation with early-acting cytokines such as stem cell factor (SCF), flt3 ligand (FL), and thrombopoietin (TPO) to amplify the hematopoietic progenitor cells.

Myeloablative treatment supported by autologous stem cell infusion with neuroblastoma.

Bcr-abl antisense oligodeoxynucleotides (AS-ODNs) have provided evidence of an antileukemia effect when tested in vitro against Philadelphia-positive cells. In order to investigate the efficacy of AS-ODNs as purging agents in chronic myeloid leukemia (CML) patients, K562 cells, a human CML cell line, were treated in vitro with various types of AS-ODNs and interferon-alpha. Cells were treated in vitro for 0 and 36 hr with 40 microgram/mL of AS-ODNs, respectively, and incubated at 37 degrees C for 36 hr.