Mesenchymal progenitors aging highlights a miR-196 switch targeting HOXB7 as master regulator of proliferation and osteogenesis.

Human aging is associated with a decrease in tissue functions combined with a decline in stem cells frequency and activity followed by a loss of regenerative capacity. The molecular mechanisms behind this senescence remain largely obscure, precluding targeted approaches to counteract aging. Focusing on mesenchymal stromal/stem cells (MSC) as known adult progenitors, we identified a specific switch in miRNA expression during aging, revealing a miR-196a upregulation which was inversely correlated with MSC proliferation through HOXB7 targeting. A forced HOXB7 expression was associated with an improved cell growth, a reduction of senescence, and an improved osteogenesis linked to a dramatic increase of autocrine basic fibroblast growth factor secretion. These findings, along with the progressive decrease of HOXB7 levels observed during skeletal aging in mice, indicate HOXB7 as a master factor driving progenitors behavior lifetime, providing a better understanding of bone senescence and leading to an optimization of MSC performance.

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 Italiano Malattie 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.

Cytogenetic abnormalities and clinical features in a patient cohort affected by three or more synchronous or metachronous primitive malignancies.

The multiple cancers (MC) phenotype represents an intriguing entity from both the clinical and the biomolecular points of view. Multiple cancers can arise in a patient either synchronously or metachronously and are frequently detected in hereditary disorders. Here we report the clinical and cytogenetic characterization of 48 patients developing at least three malignancies outside the context of a known genetic condition and 30 control individuals. Medical and pathology reports were registered, blood was collected for cytogenetic studies, and the standard G-banding technique was used for chromosomal analysis of the lymphocyte cultures. Chromosomal analysis of the peripheral blood cultures revealed high cytogenetic instability in 83% of patients' karyotypes that displayed structural rearrangements most often involving chromosomes X, 1, 6, and 7. Peculiar telomeric associations and marker chromosomes were detected in patients with a suspected cancer family history. The MC condition can be observed over a wide clinical range, which includes either apparently sporadic cases or families with a strong history of tumors. These findings indicate that Xq, 6p, and 7q are likely to harbor genes of importance in cancer development, and the present cytogenetic mapping may be crucial for further molecular genetic investigations to recognize a predictive cytogenetic signature useful to detect patients with a high risk of multiple malignancies.

Isolated extramedullary relapse after autologous bone marrow transplantation for acute myeloid leukemia: case report and review of the literature.

Isolated extramedullary relapse (IEMR) is a pattern of acute myeloid leukemia (AML) relapse post-allogeneic bone marrow transplantation (alloBMT). Less is known about IEMR post-autologous BMT (autoBMT) and about factors associated with IEMR. We report a case of a woman with M4 AML who experienced IEMR post-autoBMT and review the related literature. Seventy-two alloBMT and 3 autoBMT patients, including ours, were identified. The review suggests that an M2 or M4 French-American-British (FAB) phenotype, intermediate cytogenetic risk group, and chromosome 8 abnormalities are more frequently associated with the occurrence of IEMR. IEMR occurs earlier in autoBMT than in alloBMT. Combined treatment with radiation and high-dose chemotherapy may be effective. When we searched the European Bone Marrow Transplant Registry (EBMTR) database, we found the incidence of IEMR to be statistically greater in alloBMT than in autoBMT (11% vs. 6%; P = 0.02), but no correlations have been found with the conditioning transplant regimen used. A closer follow-up, including body and central nervous system scan, should be considered in patients who are undergoing BMT presenting with several IEMR-associated factors.

A t(11;20)(p15;q11) may identify a subset of nontherapy-related acute myelocytic leukemia.

A t(11;20)(p15;q11) is a rare but recurrent chromosomal aberration, reported in one case of polycythemia vera and a few cases of de novo acute myelocytic leukemia (AML) and therapy-related myelodysplastic syndrome (t-MDS). In t-MDS cases, the translocation resulted in the NUP98/TOP1 fusion transcript. The NUP98 gene has been suggested as the target for therapy-related malignancies. The reciprocal TOP1/NUP98 chimera, however, has not yet been encountered. We report a further case of de novo AML, subtype M2 in the French-American-British (FAB) classification, in which the reverse-transcriptase polymerase chain reaction (RT-PCR) revealed the NUP98/TOP1 chimera and also, for the first time, its reciprocal TOP1/NUP98. The literature review disclosed that, among six cases of de novo AML with t(11;20), the NUP98 gene was shown to be involved in one case and the NUP98/TOP1 chimera was detected in another. The translocation seems to be frequently associated with the FAB M2 subtype, younger age, hyperleukocytosis, and poor prognosis; thus, this translocation may identify a subset of not-therapy-related AML patients with shared clinical features.