Trisonomia 9 in pazienti affetti da MPN PH-: aspetti clinici e laboratoristici

Le neoplasie mieloproliferative ( MPN), comprendenti la Policitemia vera (PV), la Trombocitemia essenziale (TE) e la Mielofibrosi idiopatica (MFI), sono disordini clonali Philadelphia negativi caratterizzati, nel 20% dei casi, da anomalie cromosomiche ricorrenti. La trisomia 9 rappresenta la seconda anomalia cromosomica pi\uf9 frequente nelle MPN dopo la delezione 20q. Abbiamo eseguito l\u2019analisi citogenetica su aspirato midollare di una casistica monocentrica di 325 pazienti affetti da MPN; tutti i pazienti sono risultati Ph-, la trisomia 9 \ue8 stata riscontrata in 13 pazienti (9 affetti da PV e 4 da TE), in 10 casi come unica anomalia cromosomica, in un caso associata a trisomia 8 e in 2 casi in un cariotipo pi\uf9 complesso. Sono state analizzate le caratteristiche cliniche e di laboratorio e l\u2019evoluzione di malattia, al fine di individuare se tale anomalia citogenetica avesse delle particolari stigmate. I pazienti sono stati seguiti regolarmente per un periodo medio di 10,6 anni (range 1- 23 anni). L\u2019et\ue0 media alla diagnosi era 62 anni e il rapporto M:F di 1,2:1. I dati di laboratorio mostravano un valore medio di emoglobina di 16,7 g/dl, un numero medio di globuli bianchi di 9657/mmc, mentre la conta piastrinica media era di 690000/mmc. Il dosaggio dell\u2019 eritropoietina serica \ue8 risultato ridotto in tutti i pazienti e tutti presentavano la mutazione JAK2 V617F (carica allelica media 47,1%). E\u2019 interessante notare che nei pazienti affetti da TE, i valori di emoglobina alla diagnosi, pur non essendo sufficienti per porre diagnosi di PV erano comunque ai limiti superiori di norma. Dei 4 pazienti con TE, 3 (75%) sono evoluti a distanza di anni in PV, evento relativamente raro. I dati ottenuti evidenziano una maggior frequenza della trisomia 9 nei pazienti con PV rispetto alle altre neoplasie mieloproliferative ed inoltre sottolineano come i pazienti con TE portatori di tale alterazione citogenetica, abbiano un fenotipo simil-PV e un aumentato rischio di evoluzione in franca PV. Non \ue8 stata osservata trisomia 9 nelle Mielofibrosi. E\u2019 inoltre da segnalare che sul braccio corto del cromosoma 9 \ue8 stato mappato il gene JAK-2, gene che risulta mutato frequentemente nelle MPN Ph- e soprattutto nelle PV di cui rappresenta un marker molecolare

Non-random trisomies of chromosomes 5, 8 and 12 in the prolactinoma sub-type of pituitary adenomas: conventional cytogenetics and interphase FISH study

Specimens from 53 pituitary adenomas (PAs), including 17 NFPA, 16 PRL-, 9 ACTH-, 9 GH- and 2 TSH-secreting tumors, underwent cytogenetic analysis by the direct and short-term culture methods. Only 8 tumors (15%) appeared to have an abnormal karyotype. To increase the resolution of cytogenetic analysis, direct preparations from 31 PAs were investigated by interphase FISH with probes specific for chromosomes 5, 8, 12 and X, for which gain in pituitary tumors has been reported. Of these 31 PAs, 17 (54.8%) had an abnormal dosage of one or more of the 4 chromosomes tested. Separate or combined trisomies of chromosomes 5, 8 and 12 were found in 10/10 prolactinomas and in 4/9 NFPA, whereas the combined loss of chromosomes 5 and 8 was observed in 1/6 ACTH- and 1/6 GH-secreting PAs. Present and earlier data on 23 PAs showed that tumors with the highest frequency of abnormal karyotypes revealed by cytogenetics and/or interphase FISH were PRL (78%), followed by NFPA (26%) and GH (18%). Recurrent structural rearrangements affecting chromosomes 1, 3 and 12 were also identified in prolactinomas, which therefore appear to be the only pituitary adenoma sub-type with a defined trend of tumor-specific chromosomal changes. Cytogenetic and FISH analyses of different pituitary tumor sub-types indicate that they may harbour genetically distinct lesions

Molecular and phenotypic characterization of human amniotic fluid cells and their differentiation potential

The main goal of the study was to identify a novel source of human multipotent cells, overcoming ethical issues involved in embryonic stem cell research and the limited availability of most adult stem cells. Amniotic fluid cells (AFCs) are routinely obtained for prenatal diagnosis and can be expanded in vitro; nevertheless current knowledge about their origin and properties is limited. Twenty samples of AFCs were exposed in culture to adipogenic, osteogenic, neurogenic and myogenic media. Differentiation was evaluated using immunocytochemistry, RT-PCR and Western blotting. Before treatments, AFCs showed heterogeneous morphologies. They were negative for MyoD, Myf-5, MRF4, Myogenin and Desmin but positive for osteocalcin, PPARgamma2, GAP43, NSE, Nestin, MAP2, GFAP and beta tubulin III by RT-PCR. The cells expressed Oct-4, Rex-1 and Runx-1, which characterize the undifferentiated stem cell state. By immunocytochemistry they expressed neural-glial proteins, mesenchymal and epithelial markers. After culture, AFCs differentiated into adipocytes and osteoblasts when the predominant cellular component was fibroblastic. Early and late neuronal antigens were still present after 2 week culture in neural specific media even if no neuronal morphologies were detectable. Our results provide evidence that human amniotic fluid contains progenitor cells with multi-lineage potential showing stem and tissue-specific gene/protein presence for several lineages

Abnormal clones in Philadelphia negative (Ph-) cells in CML patients treated with Imatinib mesylate

Mammalian histone variant H3.3 differs from replication-dependent histone H3.1 by five amino acids, including replacement of alanine 31 by serine. H3.3 is expressed throughout the cell cycle, primarily deposited at transcriptionally active loci independent of S-phase. Data from mammalian cells suggest that phosphorylation of serine 31 (H3.3S31P) plays a role in mitosis. Here we show that H3.3S31P also occurs during mitosis of the urochordate Oikopleura dioica, suggesting this histone modification and its function in mitosis is already present at the invertebrate-vertebrate transition. The spatial pattern differed from that of H3 phosphorylation at serine 28 (H3S28P). H3S28P was enriched near telomeric regions, but H3.3S31P differed both temporally and spatially from the mammalian pattern, being more widely distributed throughout prophase, prometaphase and metaphase chromosomes. We also identified an important role for H3.3S31P during oogenic meiosis in the semelparous O. dioica. H3.3S31P initiated together with H3S28P in all meiotic nuclei in late diplotene, after H3S10P. However, H3.3S31P was retained only on the subset of meiotic nuclei that seeded maturing oocytes and proceeded through meiosis to arrest in metaphase I. Thus, this epigenetic mark is part of a regulatory circuitry that enables O. dioica to numerically adjust oocyte production over two orders of magnitude

TKIS IN CML : The appearance of abnormal clones in Ph- cells

Introduction. Tyrosine kinase inhibitors (TKIs) have changed the approach to the management of chronic myeloid leukemia (CML). Imatinib and dasatinib are potent TKIs to which most patients (pts) show a major (MCR) or complete cytogenetic response (CCR). There have been reports of clonal changes in the Ph- cells of CML pts treated with TKIs, the most common of which are trisomy chr.8 and monosomy chr.7. Materials and Methods Before and during TKI treatment, cytogenetic and FISH analyses using a dual fusion double colour probe were made of 101 pts (84 treated with imatinib, and 17 with dasatinib) diagnosed as having CML between 1999 and 2008. Results. Eight pts developed a total of nine chromosomal abnormalities, six of which occurred during imatinib and three during dasatinib treatment (Table). The (20q) deletions in the pts on imatinib were observed 43 and 54 months after starting therapy, 7 and 42 months after they had achieved CCR; the -y anomalies were observed 27 and 31 months after starting therapy, 24 and 25 months after CCR. The -y anomaly in the patient treated with dasatinib developed developed 45 months after starting therapy, six months after CCR. It is worth noting that one of the two pts with trisomy chr.8 in MCR on imatinib subsequently developed trisomy chr.9 (20 months after switching to dasatinib, 11 months after CCR): the trisomy chr.8 is still present. All of the abnormalities arising during MCR and not CCR are trisomy chr.8.Conclusions. All of the pts are still in MCR/CCR and no clinical progression or myelodisplastic disease has been documented during follow-up. Whether the TKIs played a role in the occurrence of the abnormalities remains to be determined as they could be related to CML clonal instability and/or drug effects. The prognostic implications need to be verified in a larger CML group over a longer follow-up