The main limitations of transplantation of bone marrow from donors who are matched with the recipient for only one HLA haplotype GVHD and graft failure - can be overcome. Since most patients have a relative with one haplotype mismatch, advances in this method will increase the availability of hematopoietic-cell transplantation as curative therapy for acute leukemia.

Our transplantation procedure provides reliable, reproducible CD34+ cell purification, high engraftment rates, and prevention of GvHD. The mismatched-related transplant emerges as a viable, alternative source of stem cells for acute leukemia patients without matched donors and/or those who urgently need transplantation.

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The GIMEMA ALL 0288 trial was designed to evaluate the impact of a 7-day prednisone (PDN) pretreatment on complete remission (CR) achievement and length, the influence of the addition of cyclophosphamide (random I) to a conventional 4-drug induction on CR rate and duration, and whether an early post-CR intensification (random II) by an 8-drug consolidation could improve CR duration. Median follow-up of this study was 7.3 years. From January 1988 to April 1994, among 794 adult (> 12 but < 60 years) patients registered, 778 were eligible. Their median age was 27.5 years; 73% had Blineage acute lymphoblastic leukemia (ALL) and 22% had T-lineage disease; 18% showed associated myeloid markers; 47 of 216 analyzed patients (22%) had Philadelphia chromosome-positive ALL. Response to PDN pretreatment was observed in 65% of cases. CR was achieved in 627 patients (82%). Resistant patients and induction death rates were 11% and 7%, respectively. Random II was applied to 388 patients with CR; 201 had maintenance alone and 187 had consolidation followed by maintenance. The relapse rate was 60%; isolated central nervous system relapses were 8% of all

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The proteasome inhibitor bortezomib may increase osteoblast-related markers in multiple myeloma (MM) patients; however, its potential osteoblastic stimulatory effect is not known. In this study, we show that bortezomib significantly induced a stimulatory effect on osteoblast markers in human mesenchymal cells without affecting the number of osteoblast progenitors in bone marrow cultures or the viability of mature osteoblasts. Consistently we found that bortezomib significantly increased the transcription factor Runx2/Cbfa1 activity in human osteoblast progenitors and osteoblasts without affecting nuclear and cytoplasmatic active ␤-catenin levels. IntroductionMultiple myeloma (MM) is a plasma cell malignancy characterized by the high capacity to induce osteolytic bone lesions. 1 Hystomorphometric studies showed that osteoblast formation and function are profoundly impaired in MM patients and critical in the bone lesion development. [1][2][3] Several mechanisms are involved in MMinduced osteoblast suppression 1,4,7 including the production of Wnt inhibitors as DKK-1 or sFRP-2 5,6 or the impairment of osteoblast formation and differentiation through the block of the critical osteoblast transcription factor Runx2/Cbfa1. 7 In turn, osteoblastic cells also regulate myeloma cell growth 8,9 and the increase of bone formation in mice results in a reduction of tumoral burden. 10 Recent data suggest that ubiquitin-proteasome pathway, which is the major cellular degradative system and therapeutic target in myeloma cells, 11 also regulates osteoblast differentiation. [12][13][14] The ubiquitin-proteasome pathway can modulate the BMP-2 expression, 12 which can induce osteoblast differentiation through the Wnt signaling 13 and regulates the proteolytic degradation of the osteoblast transcription factor Runx2/ Cbfa1. 14 Recently, Garrett et al 12 demonstrated that proteasome inhibitors as PS1 and epoximicin stimulate bone formation in neonatal murine calvarial bones and in vivo in mice. 12 A strong correlation between the capacity of these compounds to inhibit proteasomal activity in osteoblasts and their bone-forming activity was also demonstrated. 12 Preliminary observations obtained in MM patients treated with the proteasome inhibitor bortezomib show an increase of serum bone-specific alkaline phosphatase and other osteoblast related markers suggesting a potential osteoblast stimulatory effect of this drug. [15][16][17][18] Currently it is not known whether the proteasome inhibitor bortezomib may have a direct effect on osteoblast differentiation and formation in vitro in human cultures and in vivo in MM patients. Patients, materials, and methods DrugsBortezomib was purchased from Janssen-Cilag (Milan, Italy). For in vitro studies, the drug was reconstituted in DMSO at a stock concentration of 50 mM, and this stock was diluted in medium just before use, so that the concentration of DMSO never exceeded 0.1%. The proteasome inhibitors MG-132 and MG-262 were purchased from BIOMOL International (Plymouth Meeting, PA; DBA srl, M...

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This study was aimed to characterize the mitochondrial and extra-mitochondrial oxygen consuming reactions in human CD34؉ hematopoietic stem cells. Cell samples were collected by apheresis following pre-conditioning by granulocyte colony-stimulating factor and isolated by anti-CD34 positive immunoselection. Polarographic analysis of the CN-sensitive endogenous cell respiration revealed a low mitochondrial oxygen consumption rate. Differential absorbance spectrometry on whole cell lysate and two-dimensional blue native-PAGE analysis of mitoplast proteins confirmed a low amount of mitochondrial respiratory chain complexes thus qualifying the hematopoietic stem cell as a poor oxidative phosphorylating cell type. Confocal microscopy imaging showed, however, that the intracellular content of mitochondria was not homogeneously distributed in the CD34؉ hematopoietic stem cell sample displaying a clear inverse correlation of their density with the expression of the CD34 commitment marker. About half of the endogenous oxygen consumption was extra-mitochondrial and completely inhibitable by enzymatic scavengers of reactive oxygen species and by diphenylene iodinium. By spectral analysis, flow cytometry, reverse transcriptase-PCR, immunocytochemistry, and immunoprecipitation it was shown that the extra-mitochondrial oxygen consumption was contributed by the NOX2 and NOX4 isoforms of the O 2 . producer plasma membrane NAD(P)H oxidase with low constitutive activity. A model is proposed suggesting for the NAD(P)H oxidase a role of O 2 sensor and/or ROS source serving as redox messengers in the activation of intracellular signaling pathways leading (or contributing) to mitochondriogenesis, cell survival, and differentiation in hematopoietic stem cells.