MicroRNAs involvement in fludarabine refractory chronic lymphocytic leukemia.

Background: Fludarabine, is one of the most active single agents in the treatment of chronic lymphocytic leukemia (CLL). Over time, however, virtually all CLL patients become fludarabine-refractory. To elucidate whether microRNAs are involved in the development of fludarabine resistance, we analyzed the expression of 723 human miRNAs before and 5-days after fludarabine mono-therapy in 17 CLL patients which were classified as responder or refractory to fludarabine treatment based on NCI criteria.

Chromosome 14q32 translocations involving the immunoglobulin heavy chain locus in chronic lymphocytic leukaemia identify a disease subset with poor prognosis.

Immunophenotypic studies, fluorescence in situ hybridization (FISH) and conventional karyotyping were used to define the clinicobiological significance of 14q32 translocations involving the immunoglobulin gene locus (14q32/IGH) in 252 chronic lymphocytic leukaemia (CLL) patients. The following regions were studied: 13q14, centromere 12, 6q21; 11q22/ATM; 17p13/TP53, 14q32/IGH. Patients were classified as group 1 (favourable, i.

Mobilization of endothelial progenitor cells in patients with hematological malignancies after treatment with filgrastim and chemotherapy for autologous transplantation.

In recent years, endothelial progenitor cells (EPCs), gave rise to increasing interest because of their possible use as a therapeutic tool in the treatment of vascular lesions in ischemic tissues or as a target for anti neoplastic therapy. It has been shown that several drugs can increase the number of EPCs into the peripheral blood (PB). However, there is insufficient data concerning the mobilization and collection of EPCs during CD34+ cell mobilization.

Neoplastic circulating endothelial cells in multiple myeloma with 13q14 deletion.

In multiple myeloma (MM), circulating endothelial cells (CECs) represent a vascular marker of angiogenesis and may reflect tumor mass. In this report, we showed that, in 5 MM patients with 13q14 deletion, CECs carried the same chromosome aberration as the neoplastic plasma cells (11%-32% of CECs with 13q14 deletion). Most of the CECs displayed immunophenotypic features of endothelial progenitor cells as they expressed CD133, a marker gradually lost during endothelial differentiation and absent on mature endothelial cells.

Abnormalities of chromosomes 1p34-36, 4p16, 4q35, 9q11-32 and +7 represent novel recurrent cytogenetic rearrangements in chronic lymphocytic leukemia.

Karyotypes were studied in over 250 cases of CLL seen at our Institution and 12 cases with a previously undescribed chromosome abnormality were identified. Cytogenetic and clinicobiological features in these patients are described. Fluorescence in situ hybridization using probes for the detection of +12 and deletions of 13q14, 17p13, and 11q22-23 was performed.

CXCR-4 expression on bone marrow CD34+ cells prior to mobilization can predict mobilization adequacy in patients with hematologic malignancies.

To investigate the mechanisms of mobilization and of the factors implicated in the homing of progenitors and possibly understand the reasons for unpredicted mobilization failure, we analyzed CXCR-4 (CD184) expression on bone marrow (BM) CD34+ cells prior to peripheral blood stem cell (PBSC) mobilization in 24 patients affected by hematologic malignancies (non-Hodgkin lymphoma, multiple myeloma, and acute myeloid leukemia). We wanted to determine whether the level of CXCR-4 expressed by hematopoietic stem cells could influence mobilization process and therefore could be considered a predictive factor for mobilization adequacy. These data were also compared with stromal cell function as assessed by colony forming unit-fibroblast (CFU-F) and CFU endothelial cells (CFU-En) assays and stromal layer confluence capacity exhibited by patients' BM cells.