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G Basso

Publications and source records attributed to G Basso.

At least 91 records · Page 5Linked to original sources
PubMed1996

Retrogenic expression of the MET proto-oncogene correlates with the invasive phenotype of human rhabdomyosarcomas.

The MET oncogene encodes the receptor for HGF/Scatter Factor, known to control cell motility and invasion in epithelial cells. We report that the Met/HGF receptor, absent in differentiated adult skeletal muscles, is aberrantly expressed in clinical samples and in established cell lines of human rhadbomyosarcomas. In both the embryonal and alveolar histotypes the oncogene is overexpressed and, in some cases, amplified. The Met receptor is exposed at the cell surface and is functionally active in response to HGF/Scatter Factor. Accordingly, rhabdomyosarcoma cells exhibit an invasive phenotype in vitro in response to exogenous HGF/Scatter factor. As the factor is known to be produced by connective tissues, a paracrine stimulation of rhabdomyosarcoma invasiveness in vivo is hypothesized. Two alveolar rhabdomyosarcomas were found in co-express the ¿two-kringle' alternatively-spliced HGF/Scatter Factor variant, which has been previously shown to stimulate cell motility and matrix invasion in vitro. These cells displayed the invasive phenotype in the absence of exogenous HGF/Scatter Factor, suggesting an autocrine mechanism in vivo. These data indicate that aberrant expression of the MET proto-oncogene provides rhabdomyosarcoma cells with the same property as embryonal myoblasts to migrate into the surrounding connective tissues.

Base Sequence↗
PubMed1996

Distribution of TP53 mutations among acute leukemias with MLL rearrangements.

Acute leukemias carrying MLL rearrangements are characterized by a high degree of clinical and immunologic heterogeneity, as demonstrated by variability in their immunophenotype, consistent with lymphoid or myeloid/monoblastic derivation, as well as their occurrence in distinct age groups from infancy to adulthood. Recently, it was shown that inactivation of the TP53 tumor suppressor gene occurs frequently in cases of acute lymphoblastic leukemia carrying MLL rearrangements. In order to assess the extent of TP53 inactivation throughout the immunophenotypic and clinical spectrum of MLL+ acute leukemias, we tested for TP53 mutations 29 cases of MLL+ acute leukemias displaying lymphoid (13 cases) or myeloid/monoblastic (16 cases) features and belonging to different age groups. Mutations were detected in 6/16 myeloid/monoblastic cases and in 3/13 lymphoid cases. Among myeloid/monoblastic leukemias, the TP53 mutations occurred in 3/4 infants, but only in 3/16 cases in other age groups. Overall, our data suggest that (1) TP53 inactivation is a relatively common event in leukemias with MLL rearrangements irrespective of the leukemic phenotype and of the patients' age; (2) at least two genetic lesions (i.e., MLL rearrangement and TP53 mutation) have accumulated in the short time (few weeks after the birth or conception of the child) corresponding to the development of acute leukemias of infancy.

Acute Disease↗
PubMed1996

Analysis of cyclin-dependent kinase inhibitor genes (CDKN2A, CDKN2B, and CDKN2C) in childhood rhabdomyosarcoma.

p16INK4A, p15INK4B, and p18 proteins are highly specific inhibitors of cyclin-dependent serine/threonine kinase (CDK) activities required for GI-S transition in the eukaryotic cell division cycle. Mutations, mainly homozygous deletions, of the CDKN2A (p16INK4A/MTSI) gene have been recently found in tumor cell lines and in many primary tumors. We looked for homozygous deletions of CDKN2A, CDKN2B (p15INK4B), and CDKN2C (p18) in 12 primary rhabdomyosarcoma (RMS) specimens and in five cell lines established from this cancer type. By means of polymerase chain reaction (PCR) and PCR-single strand conformation polymorphism (PCR-SSCP), we analyzed the presence of biallelic gene deletion or point mutation causing gene function loss. All the examined tumor cell lines (100%) and three of 12 (25%) primary tumors showed homozygous deletion of CDKN2A. Furthermore, no aberrant bands in primary tumors were detected via SSCP, suggesting the absence of mutations in the coding region. In all cases the deleted area at 9p21 also involved the CDKN2B gene. Conversely, no homozygous deletion or point mutations were detected when CDKN2C was analyzed. Our results strongly indicate that the p16INK4A (and/or p15INK4B) protein plays a key role in the development and/or progression of childhood rhabdomyosarcoma and suggest that this CDK-inhibitor protein might control proliferation and/or differentiation of human muscle cells. Moreover, alteration of CDKN2C does not appear to be involved in the genesis of rhabdomyosarcoma.

Adolescent↗
PubMed1996

Peculiar allelotype associated with susceptibility to neuroblastoma.

Human neuroblastoma (NB) is characterized genetically by deletions of the short arm of chromosome I and by MYCN amplification. Loss of heterozygosity (LOH) has been found frequently for region 1p36. We have studied restriction fragment length polymorphisms (RFLPs) by using anonymous and hypervariable region (HVR) sequences to demonstrate LOH for 1p loci in 50 Italian neuroblastoma patients. Twelve cases (25%) showed LOH at one or more loci. Locus D1S94 was the most frequently involved (8/12 cases with deletion; 67%). MYCN amplification was observed in 20% of the patients. We also studied the allelic distribution in the constitutional DNA of neuroblastoma patients and of healthy Italian subjects for loci D1S112 and D1S94. A significantly (P = 0.01) different allele frequency was detected in the two groups at locus D1S94, but not at D1S112. Furthermore, the NB population was not in Hardy-Weinberg equilibrium at the former locus. This new observation suggests the existence of an allelotype associated with the susceptibility to neuroblastoma.

Alleles↗
PubMed1996

Persistence of E2A/PBX1 transcripts in t(1;19) childhood acute lymphoblastic leukemia: correlation with chemotherapy intensity and clinical outcome.

The occurrence of t(1;19) translocation was investigated by reverse transcriptase-polymerase chain reaction (RT-PCR) for the E2A/PBX1 hybrid message in a panel of 37 consecutive childhood acute lymphoblastic leukemias (ALLs). Three patients with B-precursor ALL were found to be positive at diagnosis and were re-tested during follow-up to assess the presence of minimal residual disease (MRD). Two of them became PCR-negative during treatment, whereas one remains positive 3 years after diagnosis. Since all three patients are presently in clinical and hematological complete remission, PCR detection of persistent E2A/ PBX1 transcript does not seem to affect significantly the DFS at 3 years. However, the predictivity for an eventual late relapse still remains to be assessed.

Adolescent↗
PubMed1996

Tubulointerstitial responses in the progression of glomerular diseases: albuminuria modulates alpha v beta 5 integrin.

Proteinuria represents one of the most unfavorable prognostic factors in the progression of nephropathies. Several lines of evidence support a role for proteinuria per se in the development of interstitial fibrosis, albeit the molecular mechanisms are still unknown. We investigated the potential role of integrins expressed on tubular cells in regulating the synthesis and organization of interstitial matrix or as mediators of tubulointerstitial damage in conditions mimicking the nephrotic milieu. Under basal conditions, cultured tubular cells highly expressed alpha 3 beta 1 and, at focal contacts, alpha v beta 3. In contrast, alpha v beta 5 was weakly and diffusely distributed all over the plasma membrane. Cultures on a variety of matrix substrates (fibronectin, laminin, collagen types I and IV, vitronectin, von Willebrand factor, fibrinogen) did not induce any phenotypic change in integrin expression by tubular cells. Conversely, the addition of albumin resulted in a highly increased membrane expression of beta 5, which was organized in typical focal contacts and was related to the dose of albumin added. Immunofluorescence, flow cytometry, immunoprecipitation and RT-PCR experiments argue for a complex mechanism that includes increased post-transcriptionally regulated protein synthesis, accelerated conversion of precursors to mature forms, and increased surface delivery to discrete adhesive structures. Up-regulation of the beta 5 chain in tubular cells was confirmed in 9 out of 11 kidney biopsies from proteinuric glomerulonephritides including membranous and focal sclerosing glomerulonephritis, while it was not expressed in nonproteinuric kidneys including five biopsy specimens. This is the first report indicating that proteinuria up-regulates the surface expression and distribution of a specific integrin chain on tubular cells. These observations suggest the participation of integrins in a hitherto unexplored mechanism of tubulo-interstitial responses to glomerular injury.

Albuminuria↗
PubMed1996

P16INK4A gene homozygous deletions in human acute leukaemias with alterations of chromosome 9.

Acute leukaemias are characterized by nonrandom chromosomal aberrations which are often strictly related to the inactivation of tumour suppressor genes (TSGs). Alterations at the short arm of chromosome 9 have been reported in a remarkable percentage of acute lymphoblastic leukaemias (ALL) and have been suggested to cause the loss of activity of the putative TSG, p16INK4A (MTS1/CDKN2) gene. In order to evaluate the correlation between this gene inactivation and visible cytogenetic abnormalities, we have investigated p16INK4A homozygous gene deletions in 10 paediatric acute leukaemias of different cell lineages which demonstrated karyotype aberrations involving chromosome 9. Moreover, the dimension of the genetic alteration was evaluated by studying the loss of heterozygosity of two highly polymorphic markers of chromosome 9p, namely alpha-interferon (IFNA) and D9S104, and the deletion of 5'-methylthioadenosine phosphorylase (MTAPase) gene. Finally, the deletion of a gene belonging to p16INK4A family, the p18 gene, was analysed in these acute leukaemias. Our results demonstrated that: (1) the biallelic loss of p16INK4A gene is strictly related to a specific immunophenotype, namely ALL of T-cell lineage; (ii) no significant correlation exists between alterations at chromosome 9p level and the homozygous deletions of p16INK4A gene; and (iii) p18 gene was not deleted in the examined cases. These findings suggest a possible correlation between the T-lymphocyte phenotype and the expression of p16INK4A gene. Moreover, the absence of MTAPase activity seems to be a valuable marker of p16INK4A gene inactivation, thus indicating that the deleted chromosomal area on 9p21 very frequently involves the MTAPase gene.

Base Sequence↗
PubMed1996

Interleukin-2 before and/or after autologous bone marrow transplantation for pediatric acute leukemia patients.

The role of ABMT in the treatment of acute leukemia patients with poor prognosis is controversial because of the high risk of relapse. We attempted to obtain an anti-tumor effect by administering rIL-2 pre- and/or post-ABMT. We report our experience in 10 consecutive pediatric patients: two AML late responders and eight ALL in 2nd or subsequent CR who received ABMT and rIL-2. Five patients (group A) received rIL-2 only post-ABMT. A 120 h/week rIL-2 'induction' cycle at 6 x 10(6) IU/m2/24 h was administered by continuous intravenous infusion for 2 weeks. A further six maintenance rIL-2 cycles at 18 x 10(6) IU/m2/24 h were given 72 h/week on a monthly basis. Five patients (group B) received a single 120 h cycle of rIL-2 at 6 x 10(6)/m2/24 h before BM harvesting. Three of the five group B patients entered the same protocol described above after ABMT. Increased NK and LAK activity were documented. The cycles were well tolerated; no delayed engraftment in group B was observed. One patient in group A and two patients in group B are still in CCR, respectively 47, 42 and 15 months after ABMT. Our rIL-2 regimen; pre- and/or post-ABMT, was safely tolerated and induced significant immunomodulatory effects in pediatric patients

Adolescent↗
PubMed1995

Good steroid response in vivo predicts a favorable outcome in children with T-cell acute lymphoblastic leukemia. The Associazione Italiana Ematologia Oncologia Pediatrica (AIEOP).

BACKGROUND: Improved outcome of children with acute lymphoblastic leukemia (ALL) who received intensive chemotherapy was observed by the Italian Association for Pediatric Hematology Oncology (AIEOP). To verify if this improved outcome was also extended to T-cell acute lymphoblastic leukemia (T-ALL) patients after introduction of intensive chemotherapy, treatment responses of 2011 patients, including 184 with T-ALL treated over the decade 1982-1991, were analyzed. Further, the potential use of the association of presenting clinical and biologic features with treatment outcome to determine risk factors that might be useful for planning risk-directed therapeutic studies was analyzed. METHODS: Of the 2011 children consecutively entered on the three sequential AIEOP trials ('82, '87, and '88), 1528 (76%) had successful immunologic studies of the bone marrow blasts. One hundred eighty-four (12%) had T-ALL. During these studies, four consecutive high-risk ALL treatment protocols (i.e., 8303, 8503, 8703, and 8803) were used. Because the treatment schedule in protocols 8503 and 8703 were almost identical, those patients were grouped together for the purpose of survival analysis. The 137 boys and 47 girls ranged in age from 16 months to 15.5 years (median, 7.8 years) at diagnosis, and 38% had a mediastinal mass. The rates of treatment response [i.e. complete remission (CR) and event free survival (EFS) rates] were compared for patients with T-ALL or B-cell progenitor ALL, overall and by individual study. Presenting features and early response to steroid monotherapy were also tested as possible prognostic factors. RESULTS: Overall, the CR rate was 94%, and the 7-year survival (SE) was 51.9% (4.2). T-ALL patients had a significantly worse outcome than B-lineage ALL patients [7-year EFS 40.4% (5.2) vs. 61.7% (1.7), P < 0.001]. Progressive improvement in EFS for T-ALL patients treated during 1 decade was observed, with 7-year EFS (SE) of 23.2% (8.3) for protocol 8303, 5-year EFS of 39.5% (7.1) for combined protocols 8503-8703, and 54.6% (7.1) for study '88, respectively. The analysis of prognostic factors for T-ALL patients showed that poor in vivo steroid response was the most unfavorable prognostic factor, followed by leukocyte level count > 50 x 10(9)/l (P = 0.04). The EFS for patients with T-ALL and good steroid response [63% (3.0)] was comparable with that of the unselected B-lineage ALL patients. CONCLUSIONS: EFS for patient with T-ALL has steadily increased in consecutive AIEOP ALL trials. However T-ALL patients still have a significantly worse EFS compared with patients with B-lineage ALL. Patients with T-ALL and a poor in vivo response to steroid monotherapy represent a particularly high risk treatment group.

Adolescent↗
PubMed1995

Prognostic value of rhodamine-efflux and MDR-1/P-170 expression in childhood acute leukemia.

The evidence that mechanisms other than P-170 expression may influence its "pump" and the retention/efflux of chemotherapeutic agents, prompted us to investigate the value of a functional multidrug resistance (MDR) assay in a series of childhood acute leukemia samples. Forty acute leukemia cases, mainly of lymphoid origin (ALL), were evaluated for MDR expression using a functional test based on rhodamine-123 efflux (Rhd-E). This was correlated with the quantification of P-170 external epitopes based on the positivity with the 4E3.16 and MRK16 monoclonal antibodies (MAbs). When compared with the status of the disease and response to treatment, the mean (m) Rhd-E value was significantly lower in patients at diagnosis (m = 7.1% versus m = 22.4% at relapse) and in patients who achieved a complete remission (m = 8.81% versus 31.5% in resistant cases). In the 22 samples analyzed, an overall correlation was found between the functional assay and the P-170 expression (r = 0.6), despite the much lower level of MDR positivity recognized by the immunocytometric method (m = 0.78% and 0.9% in cases at diagnosis versus m = 3.7% and 4.1% at relapse, with the 4E3.16 and MRK16 MoAbs). These data suggest that the assessment of the clinical impact of MDR expression in pediatric ALL should be based on methodological approaches capable of providing information extended to the P-170 pump function, rather then only on its gene and protein expression.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1995

Coordinate frames for naming misoriented chimerics: a case study of visuo-spatial neglect.

A persistent line of inquiry for the students of visuo-spatial neglect has involved the perceptual frame of reference respect to which the neglected region of space is defined. On standard testing conditions viewer-centered and object-centered systems of coordinates are confounded. In order to disambiguate these two reference frames FB, a patient with severe left visual neglect consequent upon a right parieto-temporal haemorrhage, was asked to identify chimeric figures presented at different orientations. FB continued to recognize poorly the left side of chimeric figures even when the display was rotated 90 degrees clockwise or anticlockwise so that the 'left' of the chimeric fell on the patient's egocentric up or down, respectively. The result suggests that, at least under the present testing conditions, unilateral neglect is tied to the principal (top-bottom) axis of the object. Object-centered vs. (viewer-centered) representational accounts of this finding are discussed.

Aged↗
PubMed1995

Extended intrathecal methotrexate may replace cranial irradiation for prevention of CNS relapse in children with intermediate-risk acute lymphoblastic leukemia treated with Berlin-Frankfurt-Münster-based intensive chemotherapy. The Associazione Italiana di Ematologia ed Oncologia Pediatrica.

PURPOSE: To assess the effect of treatment intensification and that of extended intrathecal methotrexate substitution for cranial irradiation in intermediate-risk acute lymphoblastic leukemia (ALL) children treated with a Berlin-Frankfurt-Münster (BFM)-based intensive chemotherapy. PATIENTS: Three hundred ninety-six children with non-B-ALL were enrolled onto the Associazione Italiana di Ematologia ed Oncologic Pediatrica (AIEOP) ALL 88 study. Standard risk (SR) included patients with low tumor burden (BFM risk index [RI], < 0.8); intermediate risk (IR) were patients with an RI > or = 0.8 but less than 1.2; and high risk (HR) were those with an RI > or = 1.2 or CNS involvement at diagnosis. The treatment schedule was a modified version of the ALL-BFM 86 study. CNS-directed treatment consisted of high-dose methotrexate (HD-MTX; 5 g/m2 for four courses) plus intrathecal methotrexate (IT-MTX; nine doses); IR patients additionally received extended IT-MTX (nine doses during continuation therapy); cranial irradiation was given only to HR patients. RESULTS: Of the 375 (94.7%) children who achieved remission, 1.3% had an adverse event other than relapse. The estimated event-free survival (EFS) at 6 years was 66.6% (SE 2.4) overall; 80.7% (4.5) in the SR patients, 77.5% (3.9) in the IR patients, and 54.5% (3.7) in the HR patients. Relapse occurred in 107 children (27.0%). Isolated CNS relapse occurred in 20 children (5.0%): 5 (6.3%) in the SR group, 1 (0.8%) in the IR group, and 14 (7.1%) in the HR group. The estimated 6-year CNS leukemia-free survival was 94.6% (1.2) overall: 93.5% (2.8) in the SR group, 99.1% (0.9) in the IR group, and 92.3% (2.0) in the HR group. CONCLUSION: Cranial irradiation may be omitted safely in IR ALL patients treated with BFM-based intensive chemotherapy when extended intrathecal chemotherapy is given. Because the CNS disease control was less complete in the SR group, these data challenge the effectiveness of HD-MTX for protection from CNS disease and support the protective role of extended intrathecal chemotherapy.

Adolescent↗
PubMed1995

Relations between attentional and intentional neural systems.

This study explored whether preparing an arm movement influences detection of a visual stimulus. We cued subjects to respond with either a rightward or a leftward movement to the appearance of a stimulus located either in the centre, in the left, or in the right visual field. Programming a movement toward a lateral direction enhanced visual attention at that side. Rightward movements were associated with an attentional cost only for responses to a central location, while leftward movements slowed response latencies to both central and right-sided stimuli. We hypothesized that programming a rightward movement depends on the activation of intentional centers in either cerebral hemisphere. On the contrary, leftward movements might be only driven by the contralateral hemisphere.

Adult↗
PubMed1995

p53 gene inactivation in acute lymphoblastic leukemia of B cell lineage associates with chromosomal breakpoints at 11q23 and 8q24.

The clinical heterogeneity of acute lymphoblastic leukemia (ALL) of B cell lineage reflects the presence of distinct molecular pathways leading to well-defined ALL molecular subtypes. These molecular pathways include the formation of the fusion transcripts BCR/ABL and E2A/PBX1, due to t(9;22) and t(1;19), respectively, as well as rearrangements of the MLL gene at 11q23 and of c-MYC at 8q24. Hyperdiploid ALL in the absence of chromosomal structural abnormalities is an additional ALL molecular subtype. Mutations of the RAS family genes and of the p53 tumor suppressor gene represent additional genetic lesions detected in a fraction (10-20%) of ALL cases. RAS activation in ALL may be detected in all molecular subtypes of ALL and denotes poor prognosis. Conversely, little is known regarding the clinical and biological features of ALL cases carrying p53 mutations. In order to help clarify the role of p53 inactivation in ALL development, we have determined the frequency of p53 mutations throughout the molecular spectrum of B cell lineage ALL. We report that p53 inactivation in ALL of B cell lineage is restricted to cases carrying a rearrangement of MLL or c-MYC, whereas it is consistently negative in other molecular subgroups. These data underline the molecular heterogeneity of ALL of B cell lineage and indicate that at least some of the molecular pathways involved in ALL pathogenesis require more than one genetic lesion.

Base Sequence↗
PubMed1995

Prognostic relevance of ALL-1 gene rearrangement in infant acute leukemias.

We and others have recently reported a high frequency (70-80%) of ALL-1 (MLL, HRX, HTRX) gene rearrangements in infants with acute leukemias (AL) aged less than 1 year. Preliminary observations in limited series also suggested that ALL-1 gene configuration is an important prognostic factor in this leukemic subset. We have now extended our study to a series of 45 AL patients aged between 0 and 18 months. The genomic configuration of ALL-1 in leukemic DNAs was determined by Southern blot hybridization and correlated with biological and clinical features at presentation, as well as with treatment outcome. Twenty-nine out of 45 (64%) patients showed ALL-1 rearrangements, including 4/11 (36%) infants aged between 13 and 18 months. Considering morphological types, 24/38 cases with acute lymphoblastic leukemia and 5/7 patients with acute myeloid leukemia showed ALL-1 rearrangements. The features more frequently found in association with ALL-1 rearrangements were hyperleukocytosis (P < 0.007) and CD19+/CD10- blast immunophenotype (P < 0.02). ALL-1 status was an independent prognostic marker of event-free survival (EFS) in a multivariate model including age, sex and WBC count, and maintained its statistical significance when FAB morphology was considered in the analysis by including AML patients. Considering the ALL cases the actuarial EFS was 57 and 9% for infants with germline and rearranged ALL-1 configuration, respectively (P = 0.008). A high frequency of ALL-1 gene alterations in infant AL is confirmed by this study. In addition, our results emphasize the need for extending the analysis of ALL-1 gene status to infants with AL aged > 12 months. We show that this genetic lesion is the most important variable negatively affecting prognosis in a multivariate model including other known risk factors. This latter observation should influence the choice of risk-adapted treatment strategies in this AL subset.

Chromosomes, Human, Pair 11↗
PubMed1994

Prognostic relevance of pretreatment proliferative rapidity of marrow blast cells in childhood acute lymphoblastic leukaemia.

Cell proliferation rate is a well-established prognostic factor in cancer, but it has not been considered to identify the risk group of childhood acute lymphoblastic leukaemia (ALL) at presentation. We carried out a study to demonstrate the prognostic importance of the rapidity of cell proliferation in patients with ALL. To measure the rapidity of cell proliferation we used the parameter relative to the area of silver-stained nucleolar organiser regions (AgNORs) as evaluated by morphometric analysis on smeared marrow blast cells. The mean AgNOR area of leukaemic marrow cells was measured in 119 children. By using a cut-off value of 3 microns2, we identified a group of 91 children with low proliferating blast activity (mean AgNOR value 2.11 microns2) and a group of 28 children with high proliferating activity (mean AgNOR value 3.29 microns2). The group of patients with a mean AgNOR value > 3 microns2 was characterised by a higher number of deaths, more frequent relapse and shorter time interval to relapse than the group of patients with mean AgNOR value < 3 microns2 (P < 0.01). Multivariate analysis performed to include T-cell immunophenotype, FAB morphology, leucocyte count and presence of mediastinal mass showed that the mean AgNOR value was the only independent predictor of unfavourable event-free survival probability (P > 0.01). Our results indicate that the rapidity of marrow blast cell proliferation is an important prognostic parameter in childhood ALL and should be routinely introduced in the group risk definition.

Bone Marrow↗