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Biomedical subjects

S Pilotti

Publications and source records attributed to S Pilotti.

At least 73 records · Page 4Linked to original sources
PubMed1999

PCR-based clonality analysis: a reliable method for the diagnosis and follow-up monitoring of conservatively treated gastric B-cell MALT lymphomas?

AIMS: We evaluated polymerase chain reaction (PCR) amplification of specific immunoglobulin heavy chain (IgH) gene rearrangements as a means of demonstrating monoclonality during follow-up of conservatively treated gastric MALT lymphoma, and compared the reproducibility of PCR on sequential frozen and paraffin-embedded endoscopic biopsies. We established an association between clonality detected by PCR and the histological observations. METHODS AND RESULTS: Sixty-nine pairs of sequential frozen and paraffin-embedded endoscopic biopsies from 21 conservatively treated patients were graded according to the Wotherspoon-Isaacson histological scoring system, which provides a measure of diagnostic confidence on a scale 0-5. PCR amplification of the IgH gene was performed using FR3/JH and FR2/JH primers. 68/69 paired samples (98.5%) showed identical mono- or polyclonal PCR amplification patterns. Forty-seven out of 48 pairs of samples sharing similar histological features produced identical amplification patterns in both fresh and paraffin-embedded tissues. In comparison with the histological grading, monoclonality was detected in 64.2% and 41.6% of samples scored 5 and 4, respectively. Conversely, among 64 samples scored 0-3, a monoclonal pattern was observed only in two samples, one of which was from a patient who relapsed 9 months later. CONCLUSIONS: PCR-based clonality analysis by demonstration of specific IgH gene rearrangement can be easily and reliably performed on both frozen and paraffin-embedded endoscopic biopsies. In conjunction with histological observation, this method can be used as a complementary tool to monitor MALT lymphoma regression during conservative treatment.

Clone Cells↗
PubMed1999

Biochemical uncovering of mdm2/p53 complexes in liposarcomas parallels their immunohistochemical detection.

Recent observations indicate the existence of pathogenetically distinct groups of well-differentiated (WD) dedifferentiated (DD) liposarcomas. In the retroperitoneal WD-DD liposarcomas, the predominant phenotype is represented by the aberrant (overexpressed) mdm2+/p53+ wild-type profile. At the nonretroperitoneal site, the WD liposarcomas present a wider association of MDM2/P53 gene expression; i.e., mdm2+/p53+, mdm2+/p53-, mdm2-/p53+ and mdm2-/p53-, and TP53 mutations seem to correlate with the dedifferentiation process. A biochemical study of mdm2-p53 association in 11 tumor samples characterized by the presence of different mdm2 and p53 immunophenotypes was performed. Immunoprecipitation assays using a p53-specific antibody were performed on tumor tissue and surrounding normal tissue; the immunoprecipitated material was then investigated for the presence of p53 (control) and of coimmunoprecipitated mdm2. This biochemical analysis showed that, in mdm2+/p53+/wild-type retroperitoneal liposarcomas, a band corresponded to mdm2 protein in the cellular lysates immunoprecipitated with a p53-directed antibody. In contrast, the mdm2+/p53- liposarcoma did not evidence the presence of mdm2 protein nor was p53 protein available to direct immunoprecipitation, as in the p53 mutant tumor samples with mdm2-/p53+ and mdm2-/p53- phenotypes. From the normal counterpart of retroperitoneal liposarcoma lysates, no p53 protein was immunoprecipitated. The findings in this study agree with the molecular data and they show the physical association of mdm2 and p53 in fresh liposarcoma surgical specimens.

Gene Amplification↗
PubMed1999

Dose intensification of platinum compounds with glutathione protection as induction chemotherapy for advanced ovarian carcinoma.

Based on previous clinical experience indicating the tolerability and efficacy of high-dose cisplatin with glutathione protection in the treatment of advanced ovarian cancer, this study was undertaken to explore the efficacy and feasibility of an alternative high-dose, platinum-based approach including a combination of high-dose cisplatin plus carboplatin as induction chemotherapy of advanced ovarian carcinoma and intervention surgery. Fifty consecutive eligible patients with untreated stage III or IV epithelial ovarian cancer received 40 mg/m(2) cisplatin daily on days 1-4 and 160 mg/m(2) carboplatin on day 5. The cycle was repeated after 28 days. Patients received glutathione (2,500 mg) before each cisplatin or carboplatin administration and standard intravenous hydration. After 2 courses of induction chemotherapy, the patients underwent surgical reevaluation with debulking, when possible, followed by a further 3 cycles of 120 mg/m(2) cisplatin (i.e. 40 mg/m(2) daily for 3 consecutive days plus 600 mg/m(2) cyclophosphamide on day 3) except in instances of lack of response. All eligible patients were assessed for response and toxicity. The toxicity was moderate with lack of significant nephrotoxicity. Neurotoxicity and ototoxicity were acceptable and in no patient was treatment discontinued for those toxic effects. Myelotoxicity was somewhat more severe than that observed with our previous study with high-dose cisplatin and probably related to the addition of carboplatin. Of the 40 responsive patients, 23 (46%) had a pathological complete response and 4 (8%) had a clinical complete response (without second-look laparotomy). The efficacy of the present protocol was also documented by overall survival (median survival >48 months), which appeared to be better than expected with the current therapy in this group with advanced/bulky disease. The impressive efficacy suggests a possible contribution of reduced glutathione itself in improving the outcome, as supported by preclinical studies. The results of this study should be placed in context with current platinum-based therapy including paclitaxel.

Adult↗
PubMed1999

Sequences homologous to the mouse mammary tumor virus env gene in human breast carcinoma correlate with overexpression of laminin receptor.

We previously reported that a 660-bp sequence that is homologous to the env gene of the mouse mammary tumor virus (MMTV) but not to endogenous retroviruses or to other known genes was present in 38% of human breast cancers and in some breast cancer cell lines studied (Y. Wang et al., Cancer Res., 55: 5173-5179, 1995). Here, we have investigated whether the MMTV-like sequences were associated with the clinical, pathological, and molecular parameters that have been reported to define two subsets of human breast cancers. Archival breast carcinoma samples were analyzed for four clinical parameters, obtained from patients' records, and for six pathological characteristics. Expression of c-erbB-2, p53, bcl-2, progesterone receptor, laminin receptor, and cathepsin D was detected by immunochemistry using monoclonal antibodies. PCRs were used to amplify 250 bp of the MMTV env gene-like sequence. The chi2, log-rank, and generalized Wilcoxon tests were used to analyze the data. The MMTV env gene-like sequence was detected in 37.7% of the samples. The presence of this sequence was not significantly associated with any of the pathological clinical or biological parameters studied. It did correlate, however, with expression of the laminin receptor, a marker for invasiveness and poor prognosis. This is the first phenotypic characterization of human breast cancers containing retroviral sequences.

Breast Neoplasms↗
PubMed1998

Loss of FHIT function in lung cancer and preinvasive bronchial lesions.

We previously cloned and characterized the tumor suppressor gene FHIT (fragile histidine triad) at chromosome 3p14.2 and found that this gene is altered by deletions in human tumors, including lung cancer. To assess the frequency and specificity of inactivation and its relevance in a clinical setting, we have produced antibodies against the Fhit protein and studied its expression in a series of non-small cell lung cancers and normal bronchial mucosa and a spectrum of preinvasive lesions by immunohistochemistry. The data indicate that the loss of Fhit protein is the most frequent alteration in non-small cell lung cancer (73%) and precancerous lesions (93%), is significantly higher in the tumors of smokers (75%) than in those of nonsmokers (39%; P < 0.0005), and is an independent and more frequent event than p53 overexpression in tumors and precancerous lesions (73 versus 46%). The percentage of cases lacking Fhit expression was higher in the squamous type compared to adenocarcinoma (87 versus 57%; P < 0.00001), whereas other histotypes (large cell, mucoepidermal) showed an intermediate value (69%). Loss of Fhit expression in a very high percentage of primary lung carcinomas and precancerous lesions supports the notion that FHIT alterations play an important role in the growth control of bronchial cells. FHIT inactivation is particularly important in squamous cell carcinomas that are often associated with precursor dysplastic lesions. The overall high frequency and precocity of Fhit loss in lung carcinogenesis and the development of the presently described immunohistochemical approach suggest a potential use of this gene in the early detection of lung cancer and in chemopreventive studies as an intermediate biomarker.

Acid Anhydride Hydrolases↗
PubMed1998

Prognostic value of loss of heterozygosity and KRAS2 mutations in lung adenocarcinoma.

The prognostic values of loss of heterozygosity (LOH) at loci frequently involved in non-small cell lung cancer and of KRAS2 gene mutations were studied in lung adenocarcinoma patients. LOHs were relatively common, ranging from 24% at chromosome 10p to 55% at chromosome 17p13. KRAS2 mutations at codon 12 were present in 26% of cases, were more common in male than in female patients and were associated with a smoking habit. No association between LOH at any site and clinical stage or survival rate was found. On the other hand, we observed a trend between the presence of any type of KRAS2 mutations and poor survival. Analysis of specific KRAS2 mutations showed a strong effect of Asp (GAT) and Val (GTT) mutations, resulting in a very poor survival compared with wild type group, whereas the most common mutation (Cys, TGT) was not associated with prognosis. Our results indicate the importance of specific activating mutations of the KRAS2 gene as genetic markers of clinical outcome for patients with lung adenocarcinoma.

Adenocarcinoma↗
PubMed1998

Molecular abnormalities in liposarcoma: role of MDM2 and CDK4-containing amplicons at 12q13-22.

It has recently been shown that mdm2 overexpression with stabilization of p53 represents a characteristic of retroperitoneal well-differentiated-dedifferentiated, here renamed evolved (WD-E), liposarcomas at the immunocytochemical, molecular, and cytogenetic level. This make-up appears to be confined to half the cases in non-retroperitoneal well-differentiated liposarcomas. Since in different tumours MDM2 amplification involves amplicons encompassing flanking genes, such as CDK4, the possibility was investigated that in these tumours, CDK4 could act as an alternative or additional gene involved in the transformation mechanism. Forty-one retroperitoneal (R)/non-retroperitoneal (NR) well-differentiated-dedifferentiated (WD-DD) and 33 myxoid/round cell liposarcomas were reanalysed by immunocytochemical, molecular (nine cases) and fluorescence in situ hybridization (FISH) (one case) techniques. The results showed that all but one R WD-E cases carried the mdm2+, p53+, cdk4+ immunophenotype. In NR-WD liposarcomas, this immunophenotype was shared in five cases and the remainder showed mdm2+, p53-, cdk4+ in four and mdm2-, p53-, cdk4+ in one case, showing ring chromosomes by FISH analysis. TP53 mutations are confirmed to be closely correlated with NR-DD liposarcomas and no CDK4 involvement was found in the myxoid/round cell liposarcoma group. As well as confirming the synergistic effect of MDM2 and CDK4, these results are consistent with the concept that amplicon(s) excluding MDM2 may contribute to transformation and support a role of CDK4 in opposing p53 function, particularly in NR WD liposarcoma.

Blotting, Southern↗
PubMed1998

A novel EWS-ERG rearrangement generating two hybrid mRNAs in a peripheral primitive neuroectodermal tumour (pPNET) with a t(15;22) translocation.

The occurrence of a t(15;22) translocation in a peripheral primitive neuroectodermal tumour (pPNET) has been previously reported. Molecular examination revealed the presence in tumour mRNA of two hybrid transcripts containing the 5' portion of the EWS gene fused to the 3' portion of the ERG gene. Sequence analyses indicated that both aberrant mRNAs most likely originated from the same rearrangement, which produced different hybrid isoforms due to the presence of an alternatively spliced exon in the ERG gene. To the authors' knowledge, this is the first report of the detection of two hybrid EWS-ERG mRNAs within the same tumour.

Adult↗
PubMed1998

ALK expression defines a distinct group of T/null lymphomas ("ALK lymphomas") with a wide morphological spectrum.

The t(2;5)(p23;q35) translocation associated with CD30-positive anaplastic large cell lymphoma results in the production of a NPM-ALK chimeric protein, consisting of the N-terminal portion of the NPM protein joined to the entire cytoplasmic domain of the neural receptor tyrosine kinase ALK. The ALK gene products were identified in paraffm sections by using a new anti-ALK (cytoplasmic portion) monoclonal antibody (ALKc) that tends to react more strongly than a previously described ALK1 antibody with the nuclei of ALK-expressing tumor cells after microwave heating in 1 mmol/L ethylenediaminetetraacetic acid buffer, pH 8.0. The ALKc monoclonal antibody reacted selectively with 60% of anaplastic large cell lymphoma cases (60 of 100), which occurred mainly in the first three decades of life and consistently displayed a T/null phenotype. This group of ALK-positive tumors showed a wide morphological spectrum including cases with features of anaplastic large cell lymphoma "common" type (75%), "lymphohistiocytic" (10%), "small cell" (8.3%), "giant cell" (3.3%), and "Hodgkin's like" (3.3%). CD30-positive large anaplastic cells expressing the ALK protein both in the cytoplasm and nucleus represented the dominant tumor population in the common, Hodgkin's-like and giant cell types, but they were present at a smaller percentage (often with a perivascular distribution) also in cases with lymphohistiocytic and small cell features. In this study, the ALKc antibody also allowed us to identify small neoplastic cells (usually CD30 negative) with nucleus-restricted ALK positivity that were, by definition, more evident in the small cell variant but were also found in cases with lymphohistiocytic, common, and "Hodgkin's-like" features. These findings, which have not been previously emphasized, strongly suggest that the neoplastic lesion (the NPM-ALK gene) must be present both in the large anaplastic and small tumor cells, and that ALK-positive lymphomas lie on a spectrum, their position being defined by the ratio of small to large neoplastic cells. Notably, about 15% of all ALK-positive lymphomas (usually of the common or giant cell variant) showed a cytoplasm-restricted ALK positivity, which suggests that the ALK gene may have fused with a partner(s) other than NPM. From a diagnostic point of view, detection of the ALK protein was useful in distinguishing anaplastic large cell lymphoma cases of lymphohistiocytic and small cell variants from reactive conditions and other peripheral T-cell lymphoma subtypes, as well as for detecting a small number of tumor cells in lymphohemopoietic tissues. In conclusion, ALK positivity appears to define a clinicopathological entity with a T/null phenotype ("ALK lymphomas"), but one that shows a wider spectrum of morphological patterns than has been appreciated in the past.

Anaplastic Lymphoma Kinase↗
PubMed1998

Detection of TP53 mutation, loss of heterozygosity and DNA content in fine-needle aspirates of breast carcinoma.

Recent preclinical and clinical data suggest that TP53 status and TP53 mutations may be important in determining tumour aggressiveness and therapy response. In this study we investigate the feasibility of a structural and quantitative analysis of TP53 on fine-needle aspiration (FNA) material obtained from 31 consecutive female patients with breast carcinoma, enrolled in a primary chemotherapy protocol. Tumours were screened for p53 protein overexpression and TP53 mutations (exons 5-8) using immunocytochemistry, polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and DNA sequencing analyses, and finally using fluorescence in situ hybridization (FISH) analysis. Positive nuclear staining was identified in six cases whereas mutations were detected in nine. Although the immunoreactive pattern fitted fully with the characterized TP53 mutation type, the considerable number of null p53 mutations (i.e. four) coupled with the lack of information regarding the localization of TP53 mutations make immunocytochemistry an inadequate indicator of TP53 function deregulation. Combining molecular and FISH analyses, we detected three cases with TP53 deletion and one case with deletion and mutation. Finally, DNA static-image analysis performed on 29 cases showed aneuploidy in 26 cases, which included all TP53-mutated cases. The present results show that FNA may assist clinical decisions by allowing the evaluation of a variety of biological parameters relevant for prognosis and treatment planning.

Adult↗
PubMed1998

Mutations of adenomatous polyposis coli (APC) gene are uncommon in sporadic desmoid tumours.

Desmoids are locally aggressive, non-metastasizing soft-tissue tumours, whose aetiology is still unclear. In patients affected with familial adenomatous polyposis (FAP), the incidence of desmoids is much higher than in the general population. The APC gene, which is responsible for FAP, is involved in the development of desmoids associated with this syndrome. In this study 16 sporadic and four FAP-related desmoids were analysed in order to investigate the possible involvement of APC in non-syndromic cases also. The 5' end (exons 1-11) and the coding portion of exon 15 of APC were screened using the in vitro synthesized-protein assay (IVSP). Exons 5, 6, 8-14, and a region of exon 15 spanning codons 1036-1634 were investigated by single-strand conformation polymorphism (SSCP) analysis. APC germline mutations were identified in all FAP patients, but not in sporadic cases. Somatic mutations were found in three FAP-associated desmoids (75%) and two sporadic tumours (12.5%). In one of the latter cases, both alleles were affected. These findings indicate a limited role of the gene in the development of desmoid tumours outside FAP.

Adenomatous Polyposis Coli↗
PubMed1998

Effects of short-term pre-operative tamoxifen on steroid receptor and Ki-67 expression in primary breast cancer: an immunocytochemical study.

The effects of the short-term pre-operative administration of tamoxifen (TAM, 20 mg once daily) on the tumor levels of steroid receptors and the nuclear proliferation Ki-67 antigen, were investigated in 32 elderly patients with hormone-sensitive, operable primary breast cancer by means of fine-needle aspiration biopsy (FNAB). The FNAB smears before (pre-TAM) and after six weeks of treatment (post-TAM) were stained immunocytochemically in order to obtain an H-score for steroid receptors, and the percentage of cellular nuclei containing Ki-67. The mean oestrogen receptor (ER) score between the pre- and post-TAM specimens fell from 181.2 9.7 ( SEM) to 148.1 7.9 (Wilcoxon's matched-pairs signed-rank test, p=0. 01) and there was also a significant decrease in both the mean progesterone receptor (PgR) score (178.4 10.6 vs 148.5 10.6; p=0.01) and mean Ki-67 index (8.2% 1.2 vs 4.9% 0.9; p=0.0002). The reliability of FNAB as a sampling method was checked by comparing the results of the immunocytochemical assay (ICA) of the post-TAM biopsies with those of the immunohistochemical assay (IHA) of the corresponding excised tumors. There was a positive correlation between the ICA and IHA scores: ER (Spearman's correlation coefficient, rho=0.66, p<0.001), PgR (rho=0.84, p<0.001) and Ki-67 (rho=0.96, p<0.001). We conclude that the sequential use of FNAB is a reliable means of assessing the behaviour of within-tumor biomarkers during endocrine therapy.

Aged↗