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Biomedical subjects

A Neri

Publications and source records attributed to A Neri.

At least 19 recordsLinked to original sources
PubMed2001

Deregulated FGFR3 mutants in multiple myeloma cell lines with t(4;14): comparative analysis of Y373C, K650E and the novel G384D mutations.

The t(4;14)(p16.3;q32) chromosomal translocation occurs in approximately 20% of multiple myelomas (MM) and leads to the apparent deregulation of two genes located on 4p16.3: the fibroblast growth factor receptor 3 (FGFR3) and the putative transcription factor WHSC1/MMSET. Interestingly, FGFR3 mutations known to be associated with autosomal dominant human skeletal disorders have also been found in some MM cell lines with t(4;14) but their pathogenetic role in MM is still controversial. Since cell lines may represent useful models for investigating the effects of deregulated FGFR3 mutants in MM, we analysed the expression, activation, signaling pathways and oncogenic potential of three mutants identified so far: the Y373C and K650E in the KMS-11 and OPM-2 cell lines respectively, and the novel G384D mutation here identified in the KMS-18 cell line. All of the cell lines present a heterozygous FGFR3 gene mutation and transcribe the mutated allele; unlike KMS-11 and OPM-2 (which express the IIIc isoform), the KMS-18 cell line expresses prevalently the isoform IIIb. We demonstrated that, under serum-starved conditions, KMS-11 and OPM-2 cells express appreciable levels of phosphorylated FGFR3 mutants indicating a constitutive activation of the Y373C and K650E receptors; the addition of the aFGF ligand further increased the level of receptor phosphorylation. Conversely, the FGFR3 mutant in KMS-18 does not seem to be constitutively activated since it was phosphorylated only in the presence of the ligand. In all three MM cell lines, ligand-stimulated FGFR3 mutants activated the MAP kinase signaling pathway but did not apparently involve either the STAT1 or STAT3 cascades. However, when transfected in 293T cells, G384D, like Y373C and K650E, was capable of activating MAPK, STAT1 and STAT3 under serum-starved condition. Finally, a focus formation assay of NIH3T3 cells transfected with FGFR3-expressing plasmid vectors showed that Y373C and K650E (albeit at different levels) but not G384D or the wild-type receptor, can induce transformed foci. Overall, our results support the idea that FGFR3 mutations are graded in terms of their activation capability, thus suggesting that they may play a critical role in the tumor progression of MM patients with t(4;14).

3T3 Cells↗
PubMed2001

Clinical relevance of microvessel density in laryngeal squamous cell carcinomas.

The clinical implications of microvessel density (MVD) in head and neck tumors have not been fully elucidated. We investigated the clinicopathologic correlates and prognostic relevance of MVD in a series of 122 consecutive patients with surgically treated laryngeal squamous cell carcinoma followed-up for a mean of 79 months. MVD was evaluated after CD34 immunostaining in 3 250x microscopic fields representative of the "hot spot" area, and expressed as the mean value of the vessel counts per millimeter squared. The overall median value of the intratumoral vessel count was 69.5/mm(2). In the 20 cases we analyzed, MVD increased significantly from normal to dysplastic mucosa and infiltrating carcinoma (p = 0.0001). Nineteen carcinomas (15.6%) had MVD values that were equal to or lower than the highest MVD value (52.7/mm(2)) observed in normal mucosa samples (in which the median MVD count was 34.5/mm(2), range 16.6-52.7/mm(2), mean 35.1 +/- 11.5/mm(2)) and were therefore considered poorly vascularized. Periodic acid-Schiff (PAS) staining revealed intratumoral PAS-positive connective tissue septa in 13 cases (10.7%). The patients with poorly vascularized tumors showed a tendency toward a better prognosis, but the anatomical site, tumor extension and clinical stage were the only variables significantly associated with disease-free and overall survival.

Adult↗
PubMed2001

Translocation T(4;14)(p16.3;q32) is a recurrent genetic lesion in primary amyloidosis.

Primary amyloidosis is a fatal disorder characterized by low numbers of clonal plasma cells in the bone marrow and the systemic deposition of light chain fragments in the form of amyloid. The molecular pathobiology of amyloidosis is primarily unknown. Recently, a novel karyotypically undetectable t(4;14)(p16.3;q32) translocation has been identified in approximately 20% of multiple myeloma patients. The translocation leads to the apparent deregulation of two genes located on 4p16.3, the fibroblast growth-factor receptor 3 (FGFR3), and the putative transcription factor multiple myeloma SET domain (MMSET), and to the generation of IGH/MMSET hybrid transcripts. In this study, we investigated the presence of the t(4;14) translocation in 42 AL patients using a reverse transcriptase-polymerase chain reaction assay for the detection of IGH/MMSET transcripts. Chimeric transcripts were found in six patients (14%) and were consistent with a 4p16.3 breakpoint involving intron 3 and juxtaposing IGH regions to exon 4. In three of these cases, hybrid transcripts juxtaposing IGH regions to exon 5 were also observed and were probably the result of an alternative splicing skipping exon 4. Because all of the fusion transcripts (six of six) excluded exon 3, the first translated MMSET exon, only putative 5' truncated MMSET proteins could be generated. In conclusion, our results demonstrate that the t(4;14)(p16.3;q32) translocation is a recurrent genetic lesion in primary amyloidosis.

Aged↗
PubMed2001

Brachial plexus injury and obstetrical risk factors.

OBJECTIVE: To determine whether known historical risk factors of brachial plexus injury differ between affected neonates and healthy controls. METHODS: The files of all 62 children with Erb's palsy who were diagnosed after birth were reviewed. The control group consisted of 124 randomly selected uninjured infants born within the same period. RESULTS: Compared with the control group, the mothers of the neonates with brachial plexus injury were found to be significantly older (32.1+/-5.2 years vs. 28.9+/-5.8 years, P = 0.01), and had a significantly higher incidence of diabetic pregnancy (69% vs. 14.5%, P = 0.001); the infants had a significantly higher mean birth weight (3846+/-576 g vs. 3220+/-582 g, P = 0.0001) and higher incidence of birth weight > or = 4000 g (27% vs. 4.8%, P = 0.0001). Two of the infants in the study group (3.2%) were born by elective cesarean section. CONCLUSIONS: Brachial plexus injury is associated with several non-predictable or preventable risk factors.

Adult↗
PubMed2001

IRTA1 and IRTA2, novel immunoglobulin superfamily receptors expressed in B cells and involved in chromosome 1q21 abnormalities in B cell malignancy.

Abnormalities of chromosome 1q21 are common in B cell malignancies, but their target genes are largely unknown. By cloning the breakpoints of a (1;14) (q21;q32) chromosomal translocation in a myeloma cell line, we have identified two novel genes, IRTA1 and IRTA2, encoding cell surface receptors homologous to the Fc and inhibitory receptor families. Both genes are selectively expressed in mature B cells: IRTA1 in marginal zone B cells and IRTA2 in centrocytes, marginal zone B cells, and immunoblasts. As a result of the t(1;14), IRTA1 is fused to the immunoglobulin Calpha domain to produce a chimeric IRTA1/Calpha fusion protein. In tumor cell lines with 1q21 abnormalities, IRTA2 expression is deregulated. Thus, IRTA1 and IRTA2 are novel immunoreceptors implicated in B cell development and lymphomagenesis.

Amino Acid Sequence↗
PubMed2001

Familial medullary thyroid carcinoma (FMTC). Study of one family (treatment criteria).

AIM: The nosology of familial medullary thyroid carcinoma (FMTC) has been described as a distinct pathology, genetically determined and with autosomal dominant transmission with a gene penetrance of almost 100%. The diagnosis of this morbid condition can be made if at least four members of the same family are affected by calcitonin-secreting C-cell carcinoma. METHODS AND RESULTS: We report the analysis of a family in which FMTC was diagnosed between 1993 and 1998. Of the five patients we confirmed as being affected by FMTC, we were able to perform a prophylactic thyroidectomy in only one case. The high possibility of lymph-node metastasis at the time of clinical diagnosis (52-75%), and the high morbidity and radio-chemo-resistance to adjuvant therapies, indicate total thyroidectomy with central lymph-node dissection. CONCLUSION: It appears that preventive lymphadenectomy does not substantially improve survival, while pre-clinical diagnosis is of greater importance than surgery in improving survival and preventing recurrence. Total preventive thyroidectomy has been recommended in all carriers of ret genetic defects, even in families at risk with mutations of the 618 or 620 codon, because the penetrance of FMTC approaches 100%, and a 100% accordance between presence of the disease and gene carrier status is reported. This procedure would therefore represent the only possibility of achieving a 100% cure in subjects affected by familial medullary thyroid carcinoma.

Adolescent↗
PubMed2001

Prediction of lymph node status by analysis of prognostic factors and possible indications for elective axillary dissection in T1 breast cancers.

OBJECTIVE: To identify those patients with T1 breast cancers with lower risk of nodal metastases who can safely be spared axillary dissection. DESIGN: Retrospective study. SETTING: University hospital, Italy. SUBJECTS: Review of clinical records and histopathological slides of 547 patients with T1 breast cancer, operated on between 1984 and 1997. MAIN OUTCOME MEASURES: Incidence of axillary metastases in relation to age, menopausal status, diameter and grade of tumour, vascular invasion, DNA ploidy, S-phase fraction and hormone receptor state, by univariate and multivariate analysis. RESULTS: Axillary metastases were present in 159 patients (29%). On univariate analysis, diameter of tumour 10 mm or less (pT1a/pT1b cancers), no vascular invasion, and grade 1 tumour were significantly correlated with a lower risk of nodal metastases, but only vascular invasion (p = 0.0001, odds ratio = 3.1) and diameter of tumour (p = 0.04, odds ratio = 1.6) were independent predictors on multivariate analysis. Among 34 pT1a/pT1b cancers, with low grade of tumour and no vascular invasion, only 2 (6%) had axillary metastases. When only one favourable predictive factor was associated with diameter of tumour of 10 mm or less, the incidence of axillary metastases ranged from 12% for 43 patients with grade 1 cancers to 13% for 76 patients with no vascular invasion. CONCLUSIONS: Axillary dissection may be avoided in pT1a and pT1b breast cancers (< or = 10 mm), with low grade of tumour or no vascular invasion. T1 breast cancers 10 mm or less in diameter should be treated by a two-step approach, first wide excision of the tumour and then axillary dissection or not depending on pathological examination of the primary tumour.

Adult↗
PubMed2001

Initial experience with laparoscopic adjustable gastric banding and pouch dilatation: two cases.

BACKGROUND: Late proximal pouch dilatation (LPPD) has occurred occasionally following gastric banding for morbid obesity. At present, laparoscopic conservative resetting and oversuturing of the band is considered the standard procedure for pouch dilatation without any important posterior component. METHODS: Two cases of LPPD are presented, which occurred in our initial experience with the Lap-Band, corrected via a laparoscopic approach. RESULTS: The reintervention was necessary in both patients, with conservative laparoscopic repositioning and oversuturing of the band in the first case and laparoscopic substitution of the gastric band in the second. We have not observed further complications, and weight loss has been maintained in a midterm outcome in both cases (30 and 18 months follow-up). CONCLUSIONS: LPPD can be corrected with a conservative laparoscopic surgical approach, without complications and negative functional effects on mid-term outcome.

Adult↗
PubMed2000

BCL-6 mutations are associated with immunoglobulin variable heavy chain mutations in B-cell chronic lymphocytic leukemia.

The cell of origin of B-cell chronic lymphocytic leukemia (B-CLL) is still uncertain. Recent studies have indicated that a fraction of B-CLL displays somatically mutated immunoglobulin variable heavy chain (IgV(H)) genes, which suggests an origin from a post-germinal center (GC) B cell. It has been shown that the 5' noncoding region of the BCL-6 proto-oncogene is affected by mutations in normal GC B-lymphocytes and in lymphoid malignancies displaying GC/post-GC phenotype. To further explore the cellular origin of B-CLL, we have analyzed 34 cases for mutations in the BCL-6 5' noncoding region and in the IgV(H) genes. We found somatically mutated IgV(H) genes in 24 (73%) of 33 samples (average frequency, 6.5 x 10(-2)/bp) and BCL-6 mutations in 8 (24%) of 34 cases (average frequency, 0.14 x 10(-2)/bp in the mutated cases). The occurrence of BCL-6 mutations was restricted to those cases displaying IgV(H) mutations. Analysis of BCL-6 protein expression as a marker of GC phenotype showed that, regardless of the presence of IgV(H) or BCL-6 mutations, B-CLLs express BCL-6 at levels clearly below those found in normal or transformed GC B cells. These results indicate that a subset of B-CLL derives from a cell that has been exposed to the somatic hypermutation mechanism and support the hypothesis that BCL-6 mutations result from the same process that targets immunoglobulin genes.

DNA-Binding Proteins↗
PubMed2000

Detection of t(4;14)(p16.3;q32) chromosomal translocation in multiple myeloma by reverse transcription-polymerase chain reaction analysis of IGH-MMSET fusion transcripts.

We and others have recently identified a novel recurring t(4;14)(p16.3; q32) translocation in multiple myeloma (MM) that leads to an apparent deregulation of the FGFR3 and WHSC1/MMSET genes. Because the presence of IGH-MMSET hybrid transcripts has been found in MM cell lines with t(4;14), they may represent a specific tumor-associated marker in MM. In this study, we developed a reverse transcription-PCR (RTPCR) assay for detecting chimeric transcripts from all of the 4p16.3 breakpoints identified thus far, and we used it to investigate a representative panel of 53 MM patients and 16 patients with monoclonal gammopathy of uncertain significance; in addition, t(4;14) was investigated in all of the MM patients by means of two-color fluorescence in situ hybridization. IGH-MMSET transcripts were found in 11 of the 53 (20%) MM cases and 1 of 16 (6%) cases of monoclonal gammopathy of uncertain significance. There was complete concordance between the RT-PCR and fluorescence in situ hybridization analyses of the MM cases. The results of this study indicate that RT-PCR is a sensitive and reliable method of detecting t(4;14) and suggest that it may be useful for monitoring the disease in a significant proportion of patients.

Adult↗
PubMed2000

Immunohistochemical analysis of cyclin D1 shows deregulated expression in multiple myeloma with the t(11;14).

The t(11;14)(q13;q32) chromosomal translocation, the hallmark of mantle cell lymphoma (MCL), is recurrently found in multiple myelomas (MM) by means of conventional cytogenetics. Unlike MCL, recent molecular studies of MM-derived cell lines with t(11;14) have indicated that the breakpoints are highly dispersed over the 11q13 region; however, the fact that cyclin D1 is generally overexpressed in these cell lines suggests that this gene is the target of the translocation. To evaluate further the involvement of cyclin D1 in MM, we used immunohistochemistry and fluorescence in situ hybridization to investigate cyclin D1 expression and the presence of chromosome 11 abnormalities in a representative panel of 48 MM patients (40 at diagnosis and 8 at relapse). Cyclin D1 overexpression occurred in 12/48 (25%) of cases; combined immunohistochemistry and fluorescence in situ hybridization analyses in 39 patients showed cyclin D1 positivity in all of the cases (7/7) bearing the t(11;14), in two of the 13 cases with trisomy 11, and in one of the 19 cases with no apparent abnormalities of chromosome 11. Our data indicate that the t(11;14) translocation in MM leads to cyclin D1 overexpression and that immunohistochemical analysis may represent a reliable means of identifying this lesion in MM.

Adult↗
PubMed2000

Lack of CD95/FAS gene somatic mutations in extranodal, nodal and splenic marginal zone B cell lymphomas.

Germline CD95 (also known as FAS, APT1 and APO1) gene mutations have been associated with benign lymphoproliferative diseases and autoimmune processes. Somatic mutations have been reported in human tumours, including lymphomas. Since marginal zone B cell lymphomas usually arise in a background of chronic inflammation, often of autoimmune origin, we searched for CD95 gene mutations in an unselected series of marginal zone B cell lymphomas. The CD95/FAS full coding region, comprising exon-intron junctions, was amplified from genomic DNA by polymerase chain reaction (PCR) in 10 separate reactions. PCR products were analysed by single-strand conformation polymorphism (SSCP) and visualised by silver staining. Bands exhibiting an altered electrophoretic mobility were sequenced. Twenty-seven cases of marginal zone B cell lymphomas of whom fresh or frozen tumour material was available (18 extranodal, five splenic and four nodal) were studied. Previously described silent polymorphisms in exons 7 (C836T) and 3 (T416C) were detected in 42% and in 19% of the cases, respectively. One silent T-to-A substitution at bp 431, within exon 3, was found in one case. Our results did not reveal the presence of CD95 somatic mutations in unselected cases of marginal zone B cell lymphomas. On the basis of our data, we cannot rule out that other genes coding for proteins involved in the CD95-induced apoptotic pathway might be altered. However, this pathway does not seem to play an important role in the pathogenesis of these lymphoma subtypes.

Antigens, Neoplasm↗
PubMed2000

BCL10 gene mutations rarely occur in lymphoid malignancies.

BCL10, a gene involved in apoptosis signalling, has recently been identified through the cloning of chromosomal breakpoints in extranodal (MALT-type) marginal zone lymphomas carrying the t(1;14)(p22;q32) translocation. BCL10 was also found mutated in these cases as well as in other types of lymphoid and solid tumors, suggesting that its inactivation may play an important pathogenetic role; however, this has been questioned by recent studies showing a lack of somatic mutations in human cancers. We report the mutation analysis of exons 1-3 of the BCL10 gene in DNAs from 228 cases of lymphoid malignancies (30 B cell chronic lymphocytic leukemias, 123 B and 45 T non-Hodgkin's lymphomas and 30 multiple myelomas). Somatic mutations were detected in four cases (approximately 2%): one small lymphocytic, one follicular and two diffuse large cell lymphomas. The mutations were all within exon 3 and have not been previously reported. Our data suggest that BCL10 mutations may play only a limited role in the pathogenesis of lymphoid neoplasms.

Adaptor Proteins, Signal Transducing↗
PubMed1999

Detection of t(4;14)(p16.3;q32) chromosomal translocation in multiple myeloma by double-color fluorescent in situ hybridization.

Chromosomal translocations involving the immunoglobulin heavy chain (IGH) locus at chromosome 14q32 represent a common mechanism of oncogene activation in lymphoid malignancies. In multiple myeloma (MM), variable chromosome partners have been identified by conventional cytogenetics, including the 11q13, 8q24, 18q21, and 6p21 loci. We and others have recently reported a novel, karyotypically undetectable chromosomal translocation t(4;14)(p16. 3;q32) in MM-derived cell lines, as well as in primary tumors. The 4p16.3 breakpoints are relatively scattered and located less than 100 kb centromeric of the fibroblast growth factor receptor 3 (FGFR3) gene or within the recently identified WHSC1 gene, both of which are apparently deregulated by the translocation. To assess the frequency of the t(4;14)(p16.3;q32) translocation in MM, we performed a double-color fluorescent in situ hybridization (FISH) analysis of interphase nuclei with differently labeled probes specific for the IGH locus (a pool of plasmid clones specific for the IGH constant regions) or 4p16.3 (yeast artificial chromosome (YAC) 764-H1 spanning the region involved in breakpoints). Thirty MM patients, the MM-derived cell lines KMS-11 and OPM2, and six normal controls were examined. The identification of a t(4;14) translocation, evaluated as the presence of a der(14) chromosome, was based on the colocalization of signals specific for the two probes; a cutoff value of 15% (mean + 3 standard deviation [SD]) derived from the interphase FISH of the normal controls (range, 5% to 11%; mean +/- SD, 8.16 +/- 2.2) was used for the quantification analysis. In interphase FISH, five patients (one in clinical stage I, two in stage II, one in stage III, and a plasma cell leukemia) were found to be positive (approximately 15%). FISH metaphases with split or colocalized signals were detected in only two of the translocated cases and confirmed the pattern found in the interphase nuclei. Furthermore, in three of the five cases with the translocation, FISH analysis with the IGH joining probe (JH) showed the presence of the reciprocal product of the translocation [der(4) chromosome]. Overall, our study indicates that the t(4;14)(p16. 3;q32) chromosomal translocation is a recurrent event in MM tumors and may contribute towards the detection of this lesion and our understanding of its pathogenetic and clinical implications in MM.

Aged↗
PubMed1999

EFA6, a sec7 domain-containing exchange factor for ARF6, coordinates membrane recycling and actin cytoskeleton organization.

We have identified a human cDNA encoding a novel protein, exchange factor for ARF6 (EFA6), which contains Sec7 and pleckstrin homology domains. EFA6 promotes efficient guanine nucleotide exchange on ARF6 and is distinct from the ARNO family of ARF1 exchange factors. The protein localizes to a dense matrix on the cytoplasmic face of plasma membrane invaginations, induced on its expression. We show that EFA6 regulates endosomal membrane recycling and promotes the redistribution of transferrin receptors to the cell surface. Furthermore, expression of EFA6 induces actin-based membrane ruffles that are inhibited by co-expression of dominant-inhibitory mutant forms of ARF6 or Rac1. Our results demonstrate that by catalyzing nucleotide exchange on ARF6 at the plasma membrane and by regulating Rac1 activation, EFA6 coordinates endocytosis with cytoskeletal rearrangements.

ADP-Ribosylation Factor 1↗
PubMed1999

Molecular analysis of 11q13 breakpoints in multiple myeloma.

The t(11;14)(q13;q32) chromosomal translocation, which is the hallmark of mantle cell lymphoma (MCL), is found in approximately 30% of multiple myeloma (MM) tumors with a 14q32 translocation. Although the overexpression of cyclin D1 has been found to be correlated with MM cell lines carrying the t(11;14), rearrangements of the BCL-1/cyclin D1 regions frequently involved in MCL rarely occur in MM cell lines or primary tumors. To test whether specific 11q13 breakpoint clusters may occur in MM, we investigated a representative panel of primary tumors by means of Southern blot analysis using probes derived from MM-associated 11q13 breakpoints. To this end, we first cloned the breakpoints and respective germ-line regions from a primary tumor and the U266 cell line, as well as the germ-line region from the KMS-12 cell line. DNA from 50 primary tumors was tested using a large panel of probes, but a rearrangement was detected in only one case using the KMS-12 breakpoint probe. Our results confirm previous findings that the 11q13 breakpoints in MM are scattered throughout the 11q13 region encompassing the cyclin D1 gene, thus suggesting the absence of 11q13 breakpoint clusters in MM.

Base Sequence↗