Non-traumatic hypertrophic callus of the fibula mimicking osteosarcoma in osteogenesis imperfecta type V: a case report.

We report a case of hyperplastic callus mimicking osteosarcoma in the fibula of a patient with osteogenesis imperfecta type V. Among the various imaging modalities, computed tomography was the most useful in distinguishing this rare process from a malignant entity. In addition, simple radiographs demonstrated the presence of characteristic "zebra lines", a manifestation of cyclic bisphosphonate therapy during childhood.

ETV6/GOT1 fusion in a case of t(10;12)(q24;p13)-positive myelodysplastic syndrome.

The ETV6/GOT1 fusion, resulting from t(10;12) (q24;p13), has been recently described in a myelodysplastic syndrome. We reported a second case of t(10;12)-positive myelodysplastic syndrome in whom fluorescent in situ hybridization confirmed the non-random translocation but molecular biology analyses revealed a ETV6/GOT1 chimera varying from the first case described.

ETV6-NCOA2: a novel fusion gene in acute leukemia associated with coexpression of T-lymphoid and myeloid markers and frequent NOTCH1 mutations.

PURPOSE: The ETV6 gene has been reported to be fused to a multitude of partner genes in various hematologic malignancies with 12p13 aberrations. Cytogenetic analysis of six cases of childhood acute lymphoblastic leukemia revealed a novel recurrent t(8;12)(q13;p13), suggesting involvement of ETV6. EXPERIMENTAL DESIGN: Fluorescence in situ hybridization was used to confirm the involvement of ETV6 in the t(8;12)(q13;p13) and reverse transcription-PCR was used to identify the ETV6 partner gene. Detailed immunologic characterization was done, and owing to their lineage promiscuity, the leukemic blast cells were analyzed for NOTCH1 mutations. RESULTS: We have identified a novel recurrent t(8;12)(q13;p13), which results in a fusion between the transcriptional repressor ETV6 (TEL) and the transcriptional coactivator NCOA2 (TIF2) in six cases of childhood leukemia expressing both T-lymphoid and myeloid antigens. The ETV6-NCOA2 transcript encodes a chimeric protein that consists of the pointed protein interaction motif of ETV6 that is fused to the COOH terminus of NCOA2, including the cyclic AMP-responsive element binding protein-binding protein (CBP) interaction and the AD2 activation domains. The absence of the reciprocal NCOA2-ETV6 transcript in one of the cases suggests that the ETV6-NCOA2 chimeric protein and not the reciprocal NCOA2-ETV6 is responsible for leukemogenesis. In addition, ETV6-NCOA2 leukemia shows a high frequency of heterozygous activating NOTCH1 mutations, which disrupt the heterodimerization or the PEST domains. CONCLUSIONS: The ETV6-NCOA2 fusion may define a novel subgroup of acute leukemia with T-lymphoid and myeloid features, which is associated with a high prevalence of NOTCH1 mutations.

Polycythemia vera transforming to acute myeloid leukemia and complex abnormalities including 9p homogeneously staining region with amplification of MLLT3, JMJD2C, JAK2, and SMARCA2.

Polycythemia vera (PV) is a clonal stem cell disorder characterized by an excessive erythrocyte production. At diagnosis, a normal karyotype is found in < or =80% of cases, but an abnormal karyotype frequently develops with evolution. Trisomy 9 and gains on 9p are some of the most frequent cytogenetic abnormalities, together with trisomy 8 and del(20q) in both PV and idiopathic myelofibrosis. We report the case of a 54-year-old man whose disease was classified as an acute myeloid transformation of PV. Cytogenetic and multicolor fluorescence in situ hybridization (FISH) analysis detected several chromosomal abnormalities that included an amplification of 9p. Complementary FISH analysis established amplification of the 9p22 approximately p24.3 region including several known genes: MLLT3 (alias AF9), JMJD2C (alias GASC1), JAK2, and SMARCA2 (alias BRM). JAK2(V617F) mutation status was quantitatively assessed by allele-specific quantitative polymerase chain reaction. Although crossing points analysis showed JAK2(V617F) mutated alleles at 52%, it is still impossible to describe conclusively the mutational status of the amplified JAK2 gene within the sole homogeneously staining region, because total genomic DNA was extracted for the analysis and not only DNA from cells with the homogeneously staining region. Gains on 9p being among the most common anomalies in PV, amplification of a gene or genes on this region may play a crucial role in the pathogenesis or evolution of PV.

Confirmation of a novel recurrent association: BCR-ABL t(9;22) and t(19;21).

Association of a t(9;22)(q34;q11), BCR/ABL-positive, with a dic(19;21)(p13;p13) has been described in acute lymphoblastic leukemia in relapse, raising the question of whether this association is recurrent. Described here are two cases, one of myeloproliferative disease and one of acute lymphoblastic leukemia, both presenting a masked t(9;22) and t(19;21). Chromosomal rearrangements were ascertained by fluorescence in situ hybridization (FISH) using locus-specific probes, multicolor FISH, and bacterial artificial chromosome array. These additional observations suggest a nonrandom association.

13q deletions in B-cell lymphoproliferative disorders: frequent association with translocation.

The 13q14 deletion is the most frequent abnormality in chronic lymphocytic leukemias/small lymphocytic lymphomas, and this early rearrangement is observed from the start of the disease. The systematic use of a panel of interphase fluorescence in situ hybridization (FISH) may not reveal some probes (targeting chromosomes 11q, 13q, 17p, and chromosome 12) structural abnormalities. In this series, we analyzed metaphases by conventional cytogenetics, followed by interphase and metaphase fluorescence in situ hybridization. We were able to observe 17 cases of 13q translocations with deletions in eight of them. Three distinct regions were involved by translocations in association with or without deletions: a region centromeric to RB1 (13q11 approximately 13), a zone telomeric to D13D25 (13q21 approximately 31), and a 13q14 region deliniated by RB1 and D13S25. In this area, the deletion was variable: RB1 alone (one case), D13S319 approximately D13S25 (five cases), and from RB1 to D13S25 (two cases). The very high frequency of 13q14 loss suggests that these deletions are of pathogenetic importance, but, the importance of the translocations remains to be determined.

Five members of the CEBP transcription factor family are targeted by recurrent IGH translocations in B-cell precursor acute lymphoblastic leukemia (BCP-ALL).

CCAAT enhancer-binding protein (CEBP) transcription factors play pivotal roles in proliferation and differentiation, including suppression of myeloid leukemogenesis. Mutations of CEBPA are found in a subset of acute myeloid leukemia (AML) and in some cases of familial AML. Here, using cytogenetics, fluorescence in situ hybridization (FISH), and molecular cloning, we show that 5 CEBP gene family members are targeted by recurrent IGH chromosomal translocations in BCP-ALL. Ten patients with t(8;14)(q11;q32) involved CEBPD on chromosome 8, and 9 patients with t(14;19)(q32;q13) involved CEBPA, while a further patient involved CEBPG, located 71 kb telomeric of CEBPA in chromosome band 19q13; 4 patients with inv(14)(q11q32)/t(14;14)(q11;q32) involved CEBPE and 3 patients with t(14;20)(q32;q13) involved CEBPB. In 16 patients the translocation breakpoints were cloned using long-distance inverse-polymerase chain reaction (LDI-PCR). With the exception of CEBPD breakpoints, which were scattered within a 43-kb region centromeric of CEBPD, translocation breakpoints were clustered immediately 5' or 3' of the involved CEBP gene. Except in 1 patient with t(14;14)(q11;q32), the involved CEBP genes retained germ-line sequences. Quantitative reverse transcription (RT)-PCR showed overexpression of the translocated CEBP gene. Our findings implicate the CEBP gene family as novel oncogenes in BCP-ALL, and suggest opposing functions of CEBP dysregulation in myeloid and lymphoid leukemogenesis.

HOX11L2/TLX3 is transcriptionally activated through T-cell regulatory elements downstream of BCL11B as a result of the t(5;14)(q35;q32).

The t(5;14)(q35;q32) chromosomal translocation is specifically observed in up to 20% of childhood T-cell acute lymphoblastic leukemia (T-ALL). It affects the BCL11B/CTIP2 locus on chromosome 14 and the RANBP17-TLX3/HOX11L2 region on chromosome 5. It leads to ectopic activation of TLX3/HOX11L2. To investigate the reasons of the association between t(5;14) and T-ALL, we isolated the translocation breakpoints in 8 t(5;14) patients. Sequence analyses did not involve recombinase activity in the genesis of the translocation. We used DNAse1 hypersensitive experiments to locate transcriptional regulatory elements downstream of BCL11B. By transient transfection experiments, 2 of the 6 regions demonstrated cis-activation properties in T cells and were also effective on the TLX3 promoter. Our data indicate that the basis of the specific association between t(5;14) and T-ALL lies on the juxtaposition of TLX3 to long-range cis-activating regions active during T-cell differentiation.

Overexpression of CEBPA resulting from the translocation t(14;19)(q32;q13) of human precursor B acute lymphoblastic leukemia.

Subtle variation in the expression or function of a small group of transcription factors can drive leukemogenesis. The CEBPA protein is known to regulate the balance between cell proliferation and differentiation during early hematopoietic development and myeloid differentiation. In human myeloid leukemia, CEBPA is frequently inactivated by mutation and indirect and posttranslational mechanisms, in keeping with tumor suppressor properties. We report that CEBPA is activated by juxtaposition to the immunoglobulin gene enhancer upon its rearrangement with the immunoglobulin heavy-chain locus in precursor B-cell acute lymphoblastic leukemia harboring t(14;19)(q32;q13). Overexpression of apparently normal CEBPA RNA or protein was observed in 6 patients. These data indicate that CEBPA may exhibit oncogenic as well as tumor suppressor properties in human leukemogenesis.

Cytogenetic studies of a series of 43 consecutive secondary myelodysplastic syndromes/acute myeloid leukemias: conventional cytogenetics, FISH, and multiplex FISH.

We report a series of 43 consecutive therapy-related myelodysplastic syndromes (t-MDS) or acute myeloid leukemias (t-AML) observed for 6 years. This series consisted of 26 women and 17 men, ages ranging from 9 to 85 years. These cases were classified into three groups according to the primary diagnosis. Conventional cytogenetic and fluorescent in situ hybridization (FISH)/ multiplex FISH (M-FISH) methods were used to analyze cytogenetic characteristics of secondary MDS/AML. The features of chromosomal abnormalities were linked to the nature of the therapy and protocols used. A considerable proportion of recurrent balanced translocations characterized t-AML secondary to therapy. FISH techniques showed that conventional cytogenetics often underestimated associated translocations; some deletions were in fact derivative chromosomes associated with deletions. After treatment for lymphomas and chronic myeloproliferative diseases, there were more complex unbalanced abnormalities than the control group. Compared to other series, recurrent translocations appeared to be more numerous (25%), probably reflecting an evolution of therapeutic modalities.

Identification of distinct molecular phenotypes in acute megakaryoblastic leukemia by gene expression profiling.

Individuals with Down syndrome (DS) are predisposed to develop acute megakaryoblastic leukemia (AMKL), characterized by expression of truncated GATA1 transcription factor protein (GATA1s) due to somatic mutation. The treatment outcome for DS-AMKL is more favorable than for AMKL in non-DS patients. To gain insight into gene expression differences in AMKL, we compared 24 DS and 39 non-DS AMKL samples. We found that non-DS-AMKL samples cluster in two groups, characterized by differences in expression of HOX/TALE family members. Both of these groups are distinct from DS-AMKL, independent of chromosome 21 gene expression. To explore alterations of the GATA1 transcriptome, we used cross-species comparison with genes regulated by GATA1 expression in murine erythroid precursors. Genes repressed after GATA1 induction in the murine system, most notably GATA-2, MYC, and KIT, show increased expression in DS-AMKL, suggesting that GATA1s fail to repress this class of genes. Only a subset of genes that are up-regulated upon GATA1 induction in the murine system show increased expression in DS-AMKL, including GATA1 and BACH1, a probable negative regulator of megakaryocytic differentiation located on chromosome 21. Surprisingly, expression of the chromosome 21 gene RUNX1, a known regulator of megakaryopoiesis, was not elevated in DS-AMKL. Our results identify relevant signatures for distinct AMKL entities and provide insight into gene expression changes associated with these related leukemias.

Endotoxin-induced heart dysfunction in rats: assessment of myocardial perfusion and permeability and the role of fluid resuscitation.

OBJECTIVE: The pathophysiology of sepsis-induced myocardial dysfunction is still controversial. Whether microcirculatory hypoperfusion together with capillary leakage can occur in the heart wall also remains a matter of debate. The objective was to evaluate the impact of fluid resuscitation on endotoxin-induced myocardial dysfunction. DESIGN: Adult rats were given intraperitoneal injection of endotoxin (lipopolysaccharide, Escherichia coli, 10 mg/kg) or phosphate-buffered solution, followed up by echocardiography and acetate micro-positron emission tomography scan imaging, together with final hemodynamic, biochemical, and pathologic evaluations up to 48 hrs. SETTING: University laboratory. SUBJECTS: Pathogen-free male Wistar rats (350 g). INTERVENTIONS: Influence of isovolumic fluid infusion type (saline vs. pentastarch) on these variables was assessed in 11 groups of six animals including an unchallenged control one. MEASUREMENTS AND MAIN RESULTS: Endotoxin injection induced a) myocardial dysfunction (decrease of approximately 15-20% in left ventricular ejection fraction); b) ventricular enlargement (approximately 1.5- to 1.7-fold increase in left ventricular systolic volume); c) cardiac output increase (10-15%); d) myocardial hypoperfusion ( approximately 1.5- to 2-fold decrease in acetate k1 constant rate); e) increased oxygen consumption (k2); and f) interstitial wall increase. Endotoxin injection also enhanced levels of arterial lactates and troponin I. Colloid (pentastarch) over crystalloid (saline) fluid resuscitation significantly reversed echocardiographic changes, some positron emission tomography imaging alterations, and lactate and troponin I levels without further enhancing interstitial spaces. CONCLUSION: Endotoxin can induce reversible myocardial alterations with evidence of coronary hypoperfusion and heart wall enlargement/damage, some of which can be prevented by fluid resuscitation. The use of crystalloids is less beneficial than pentastarch.

Circulating cell-derived microparticles in Crohn's disease.

Procoagulant membrane microparticles can be released from activated or apoptotic cells in response to various environmental stimuli. The aim of this study was to investigate the presence of microparticles in Crohn's disease and to assess their variations after infliximab therapy. We compared the levels of circulating microparticles in 38 patients with Crohn's disease, 16 patients with ulcerative colitis, 7 patients with infectious colitis, and 17 control subjects. The evolution of microparticle levels was assessed after infliximab therapy in 13 patients with Crohn's disease. Circulating microparticle levels were elevated in patients with Crohn's disease (9.31+/-0.66 nmol/L phosphatidylserine equivalent [PS Eq]) or infectious colitis (10.71+/-0.92 nmol/L PS Eq) compared to patients with ulcerative colitis (5.75+/-0.59 nmol/L PS Eq) and control subjects (4.06+/-0.37 nmol/L PS Eq) (P = 0.001). Infliximab induced a significant diminution of the amounts of circulating microparticles, from 10.33+/-1.20 to 6.45+/-0.90 nmol/L PS Eq (P = 0.002). Generation of circulating microparticles occurs in Crohn's disease; infliximab induces significant diminution. Release of microparticles could be linked to the type of inflammatory response underlying Crohn's disease.

Clinical significance of HOX11L2 expression linked to t(5;14)(q35;q32), of HOX11 expression, and of SIL-TAL fusion in childhood T-cell malignancies: results of EORTC studies 58881 and 58951.

In a series of 153 children with T-cell malignancies enrolled in 2 consecutive European Organization for Research and Treatment of Cancer (EORTC) trials, we assessed the HOX11L2 expression and/or the presence of a t(5;14)(q35;q32). Additionally, in 138 of these patients, HOX11 expression and SIL-TAL rearrangement were also assessed. These alterations were mutually exclusive, and their frequency was 23% (n = 35), 7% (n = 10), and 12% (n = 17), respectively. HOX11L2/t(5;14) positivity was more frequent in acute lymphoblastic leukemia (ALL) with cortical T immunophenotype and in children aged between 6 and 9 years. In contrast with previously reported data, patients positive and negative for HOX11L2/t(5;14) were comparable with regard to clinical outcome as well as to the response to a 7-day prephase treatment or to residual disease at completion of induction therapy. The 3-year event-free survival (EFS) rate (+/- SE percentage) for patients positive and negative for HOX11L2/t(5;14) was 75.5% (+/- 8.1%) and 68.3% (+/- 5.0%), respectively; the hazard ratio was 0.84 (95% confidence interval, 0.40-1.80). Patients with HOX11-high expression and those with SIL-TAL fusion had low levels of residual disease at the end of induction and a favorable prognosis: the 3-year EFS rate was 83.3% (+/- 8.5%) and 75.3% (+/- 12.6%), respectively. The results obtained in HOX11L2/t(5;14) patients in this study do not confirm the unfavorable prognosis reported in previous studies.

Presence and localization of CCK receptor subtypes in calf pancreas.

This study was undertaken to confirm the presence of CCK receptor subtypes in calf pancreas and establish their cellular localization. Using specific antibodies against CCKA and CCKB receptors, somatostatin, glucagon and insulin, we were able to confirm by Western blot the presence of both CCK receptor protein subtypes in the calf pancreas as a 80-85-kDa CCKA receptor and 40-45-kDa CCKB receptor. By immunofluorescence, the CCKB receptor colocalizes with the islets' somatostatin delta cells, confirming what was previously shown in other species, as well as on ductal cells. We could not reproduce in the calf its colocalization with glucagon alpha cells as observed in human and rat. Any specific localization of CCKA receptors with our multiple antibodies failed. Our observation that the CCKB receptor subtype is specifically localized on pancreatic delta cells as well as on ductal cells lets us support the hypothesis that in this species, CCK could be involved in somatostatin metabolism as well as hydrelatic secretion; its effect on enzyme secretion would be indirect.

Cytogenetic profile of childhood and adult megakaryoblastic leukemia (M7): a study of the Groupe Français de Cytogénétique Hématologique (GFCH).

To draw the cytogenetic profile of childhood and adult acute megakaryoblastic leukemia (M7), the Groupe Français de Cytogénétique Hématologique collected 53 cases of M7 (30 children and 23 adults). Compared to other acute myeloid leukemias, M7 is characterized by a higher incidence of abnormalities, a higher complexity of karyotypes, and a different distribution of abnormalities among children and adults. Nine cytogenetic groups were identified: normal karyotypes (group 1), patients with Down syndrome (group 2), numerical abnormalities only (group 3), t(1;22)(p13;q13) or OTT-MAL transcript (group 4), t(9;22)(q34;q11) (group 5), 3q21q26 (group 6), -5/del(5q) or -7/del(7q) or both (group 7), i(12)(p10) (group 8), and other structural changes (group 9). Groups 1, 2, 3, and 4 were exclusively composed of children (except one adult in group 3), whereas groups 5, 6, 7, and 8 were mainly made up of adults. The main clinical and hematologic features of these groups were described. No new recurrent abnormality was identified, but mapping of all breakpoints allowed us to specify several possible hot spots of rearrangement: 17q22-23, 11q14-21, 21q21-22, and 16q21-22-23. Although 90.5% of cases had no documented antecedent hematologic disorder or exposure to chemotherapy or radiotherapy, the morphologic and the cytogenetic findings indicated that M7 might be a secondary leukemia more often than suggested by preceding history, particularly among adults. The concurrent analyses of morphologic and cytogenetic data also led us to assume that the initial precursor involved might be more immature in adult than in childhood M7.

Evaluation of ETF1/eRF1, mapping to 5q31, as a candidate myeloid tumor suppressor gene.

Interstitial deletion of the long arm of chromosome 5 is a recurrent abnormality, mainly associated with myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML), and it has been proposed therefore that the deleted region may contain a myeloid tumor suppressor gene. We have recently mapped a human translation termination factor gene, ETF1, to band 5q31 at D5S500, and thus to the smallest commonly deleted segment. We have evaluated ETF1 as a candidate myeloid tumor suppressor gene by analysis of the human acute myeloid leukemia cell line HL60, and of patients suffering from malignant myeloid diseases with cytogenetically-defined abnormalities of chromosome 5. Fluorescence in situ hybridization analysis revealed hemizygous loss of the ETF1 locus in HL60 cells and in four of five leukemic samples, but no inactivating mutations were identified by sequencing of the remaining ETF1 allele.