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L Leoncini

Publications and source records attributed to L Leoncini.

At least 19 recordsLinked to original sources
PubMed2006

Hereditary diffuse gastric cancer and E-cadherin: description of the first germline mutation in an Italian family.

AIMS: Germline mutation of the E-cadherin gene (CDH1) accounts for the Hereditary Diffuse Gastric Cancer (HDGC) syndrome. Fourteen pedigrees with Diffuse Gastric Cancer that fulfilled the International Gastric Cancer Linkage Consortium (IGCLC) criteria were selected and screened for CDH1 germline mutations. METHODS: The entire coding region of the CDH1 gene and all intron-exon boundaries were analyzed by direct sequencing in the 14 families fulfilling the IGCLC criteria. E-cadherin immunohistochemical expression was evaluated on tumour as well as normal formalin-fixed paraffin embedded tissues. RESULTS: A novel germline missense mutation was found. It was a single C-->T substitution in exon 8, resulting in a transition of CCG-->CTG (C1118T; Pro373Leu) demonstrated in the proband and her brother. At immunohistochemical analysis, the staining intensity was reduced and considered weakly positive (15%). CONCLUSIONS: The first CDH1 germline mutation of an Italian family is herein reported. The present missense mutation has never been described so far.

Cadherins↗
PubMed2006

Retinoblastoma gene family expression in lymphoid tissues.

It appears more and more clear that retinoblastoma (RB) family of proteins represents key molecules in tumour suppression. This family consists of pRb/p105, p107 and pRb2/p130, which participate in a gene regulatory network that governs the cellular response to antimitogenic signals, and whose deregulation constitutes one of the hallmarks of cancer. Irrespective of their structural and biochemical similarities, RB proteins carry out different functional tasks. The expression of RB gene family in the reactive lymphoid tissues again confirms the different role of each member in cell cycle control and differentiation of normal cells. These different functional properties appear to be maintained in tumours lymphoid tissues, where alterations of the RB/p105 gene appear to be relatively rare. In this review, we will summarize the current knowledge about the role of the RB proteins in reactive and neoplastic lymphoid tissue.

Cell Cycle↗
PubMed2006

Secretory endometrium highly expresses urocortin messenger RNA and peptide: possible role in the decidualization process.

BACKGROUND: Urocortin (UCN) gene expression and synthesis have been reported in epithelial and stromal cells of the human endometrium. In this study we evaluated (i) UCN messenger RNA (mRNA) expression and peptide production in uterine specimens collected throughout the endometrial cycle, (ii) UCN secretion after decidualization of cultured human endometrial stromal cells (HESCs) and (iii) the effect of UCN on endometrial decidualization. METHODS: HESCs were isolated from samples of human endometrium collected from healthy patients with normal menstrual cycle and cultured in presence of cAMP, 17-beta-estradiol (E(2)) + medroxyprogesterone acetate (MPA) and UCN. UCN levels were measured in endometrial extracts by an enzyme immunoassay, and changes of endometrial UCN mRNA expression were measured by RT-PCR analysis. RESULTS: UCN peptide concentrations and mRNA expression were highest in the secretory phase of the menstrual cycle (P < 0.001, late secretory versus early and late proliferative phase) and higher in the late than the early secretory phase (P < 0.01). After decidualization of HESC with cAMP or E(2) + MPA, UCN levels rose in parallel with prolactin concentrations by days 6 (P < 0.01, for all). Finally, the addition of UCN to HESCs, with or without E(2) + MPA, induced the release of prolactin. CONCLUSIONS: The evidence that (i) UCN is highly expressed in the secretory phase of the endometrial cycle; (ii) cAMP and E(2) + MPA modulate secretion of UCN and (iii) UCN induces HESCs decidualization together suggest a possible role for UCN in endometrial physiology.

Adult↗
PubMed2006

The effects of HIV-1 Tat protein on cell cycle during cervical carcinogenesis.

The role of HPV in the carcinogenesis of intraepithelial and invasive anogenital lesions is currently well established. E6 and E7 oncoproteins of high-risk HPV genotypes are known to inactivate p53 and pRb pathways. Several studies have described an increased prevalence and recurrence of both cervical HPV infection and invasive cervical cancer among HIV-1 positive women compared to HIV-1 negative cases. For these reasons, cervical cancer is considered an AIDS-defining neoplasm. Unlike other AIDS-associated neoplasms, the occurrence of cervical cancer is independent of immune suppression. HIV-1 infection in patients with high grade precancerous lesions and invasive cervical cancers results in a therapy refractory and more aggressive disease phenotype, which is not yet well understood at the molecular level. An upregulation of HPV E6 and E7 gene expressions by HIV-1 proteins such as Tat has been documented by some authors. However, the role of HIV-1 in cervical carcinomas is still unclear. It is already known that HIV-1 Tat protein is able to influence cell cycle progression. Altogether, these facts led us to investigate the effects of Tat on the expression of cell cycle regulator genes. After transfection of HeLa cells with Tat, we analyzed the expression of cell cycle regulators from these cells by IHC and Real-time PCR. A significant reduction in the expression of cell cycle inhibitors of transcription and an increase in the levels of proliferation markers were observed. These results suggest that HIV-1 may enhance cervical carcinogenesis by promoting cell cycle progression. We also found that this HIV-1 Tat-induced cell proliferation was not dependent on the E2F family of transcription factors, and therefore postulate that Sp factors may be involved.

Cell Cycle↗
PubMed2006

IRTA1+ monocytoid B cells in reactive lymphadenitis show a unique topographic distribution and immunophenotype and a peculiar usage and mutational pattern of IgVH genes.

The origin and function of monocytoid B cells (MBCs) are poorly understood. Taking advantage of their strong expression of IRTA1 (a receptor that is also associated with MALT marginal zone B cells), we have comprehensively analysed MBCs in 25 cases of lymphadenitis of different aetiologies, shedding new light on the topographical distribution, immunophenotype and IgV(H) gene usage and mutational profile of this B cell subset. IRTA1(+) MBCs, although predominantly located in the subcapsular and intermediary sinuses, were also observed scattered within germinal centres (GCs) in all lymphadenitis cases examined. The molecular characterization of IgV(H) genes revealed that IRTA1(+) MBCs residing in different areas of the lymph node (subcapsular sinus, intermediary sinuses and GCs) can be clonally related (with intraclonal variation), and that those located in GCs are consistently more mutated and selected for expression of a functional antigen receptor than those located in the sinuses. Moreover, by contrast, IRTA1(+) MBCs in GCs express the memory B cell marker CD27. Finally, in toxoplasmic lymphadenitis, the IRTA1(+) MBC population shows a highly preferential usage of the V(H) genes 3-7 and 3-30 (without any obvious peculiarity in their CDR3s), possibly suggesting that a superantigen expressed by Toxoplasma gondii may be involved in the early activation of this B cell subset.

B-Lymphocyte Subsets↗
PubMed2006

Update on extranodal lymphomas. Conclusions of the Workshop held by the EAHP and the SH in Thessaloniki, Greece.

Classification and proper treatment of extranodal lymphoma is hindered by the diversity of lymphoma types and the relative rarity of many of these tumour types. In order to review controversial issues in extranodal lymphoma diagnosis, a joint Workshop of the European Haematopathology Association (EAHP) and the Society for Hematopathology (SH) was held, where 99 selected cases were reviewed and discussed. This Workshop summary is focused on the most controversial aspect of cutaneous B-cell lymphoma, other extranodal B-cell lymphomas, plasmablastic lymphoma and anaplastic large-cell lymphoma in extranodal sites, and makes practical recommendations about diagnosis and therapeutic approaches.

Diagnosis, Differential↗
PubMed2006

[The Haemolymphopathology Italian Group (H.I.G.): an essential resource for the new technical and organization problems troubling modern haemolymphopathology diagnostics].

Recently, many progresses have been recorded in the molecular and histogenetic characterization of the haematopoietic and lymphoid tumours, resulting in important classifying changes. As a consequence, the exact definition of lymphoma subtype requires an integration between traditional morphologic "expertise" and several bio-functional data obtained from advanced and complex ancillary techniques (immunohistochemistry, molecular biology and cytogenetics). At the same time, the data provided by gene expression profiling studies are going to deeply modify the therapies in haematological cancers. These studies are expected to allow the achievement of single-patient-tailored genic therapy; for this reason it is necessary to get biological samples of good quality. Indeed, while these progresses contribute to highlight the pathologist's diagnostic role, they should make us reflect on the state of the art of the Italian haemolymphopathology diagnostics and on its ability to cope up with the new challanges. The aim of this article is to outline a realistic picture of the present condition, and to explain the reasons for setting up, inside SIAPEC-IAP, the Haemolymphopathology Italian Group (H.I.G.). The purpose of H.I.G. will be twofold: first of all, scheduling of a series of projects so as to the haemolymphopathological diagnostic standardization; secondly, building a national network among all the pathologists involved in this exciting and complex field of the anatomic pathology.

Europe↗
PubMed2005

Aggressive B-cell lymphomas: a review based on the workshop of the XI Meeting of the European Association for Haematopathology.

The generic term aggressive B-cell lymphoma includes a variety of entities, each with particular diagnostic and therapeutic issues. To define these entities better and to help confront such issues, a workshop was organized by the European Association of Haematopathology (EAHP) and the Society of Haematology during the XI Meeting of the EAHP, held in Italy in May 2002. Participants were asked to submit cases under various categories and all cases submitted were examined and reviewed by the panel members. The panel's diagnoses formed the basis for discussion at the workshop and a limited number of cases were selected to be presented in more detail and discussed during the workshop. After the workshop the panel met again to discuss the outcome, summarized in this report, which describes the panel's proposals regarding diagnostic criteria, terminology, the definition of new entities and evaluation of biological differential and new prognostic parameters.

Biomarkers, Tumor↗
PubMed2003

Pathologic aspects of AIDS malignancies.

Since the emergence of the HIV pandemic, a close association between HIV infection and the development of a selected group of cancers has been acknowledged. The introduction of highly active antiretroviral therapy, however, has had a dramatic impact on the incidences of several AIDS-defining malignancies. This suggests the possibility of a direct and indirect role of HIV in HIV-related tumor genesis. The aim of this paper is to review the pathology of AIDS-related malignancies, taking into account the pathogenetic mechanisms and their potential for improving the treatment of these tumors.

Acquired Immunodeficiency Syndrome↗
PubMed2003

Cytokeratin-positive interstitial cell neoplasm: a case report and classification issues.

AIMS: Tumours of dendritic/accessory cell origin are rare neoplasms arising in lymph nodes. Among these, tumours derived from cytokeratin-positive interstitial reticulum cells (CIRCs), a subset of fibroblastic reticulum cells, are reported even less frequently. The International Lymphoma Study Group (ILSG) has recently proposed a classification for tumours of histiocytes and accessory dendritic cells in which CIRC tumours are not included. We report a case of a CIRC tumour arising in a submandibular lymph node of a 66-year-old male. METHODS AND RESULTS: The neoplasm was composed of spindle cells with elongated or round nuclei, prominent nucleoli and abundant cytoplasm. These cells were arranged in a diffuse fascicular and vaguely whorled pattern. The tumour cells stained diffusely for S100, vimentin, desmin, lysozyme, and focally for CD68 and cytokeratins 7, 8, 18, CK-AE1 and CK-pool. Electron microscopy was performed for further evaluation on samples taken from the paraffin block; this revealed cytoplasmic projections and rudimentary cell junctions. CONCLUSIONS: Histopathologist should be aware of the existence of tumours deriving from CIRCs, as these cases may be misdiagnosed as metastatic carcinoma. Careful clinical and pathological evaluation is necessary to exclude this possibility.

Aged↗
PubMed2003

Burkitt's lymphoma: new insights into molecular pathogenesis.

The World Health Organisation classification reports three subcategories of Burkitt's lymphoma (BL)--endemic, non-endemic, and immunodeficiency associated--proposed to reflect the major clinical and genetic subtypes of this disease. These different types of BL have been reviewed and studied by immunohistochemistry and molecular methods. The results point out the heterogeneity of BL and suggest that AIDS related BL may have a different pathogenesis from that of classic BL.

Adolescent↗
PubMed2003

Factors predicting the persistence of genital human papillomavirus infections and PAP smear abnormality in HIV-positive and HIV-negative women during prospective follow-up.

As part of an extensive multi-institutional DIANAIDS study focused on assessing the risk factors, natural history, diagnosis and follow-up of genital human papillomavirus (HPV) infections in HIV-infected women, the present communication reports a sub-cohort of 142 women (89 HIV+ and 48 HIV-), followed-up for a mean of 14.07 (+/-10.84) months to analyse the factors predicting the persistence and clearance of HPV infections (polymerase chain reaction [PCR] and sequencing) and cervical Papanicolaou (PAP) smear abnormalities, using both univariate (Kaplan-Meier) and multivariate (Cox) survival analysis. The appearance of new HPV infections during the follow-up was significantly more frequent in HIV-positive than in HIV-negative women, odds ratio (OR) 8.800 (95% confidence interval [CI]: 1.199-64.611), and also the clearance rate was significantly less frequent in HIV-positive than in HIV-negative women, 69.2% vs 22.8%, respectively (OR 0.330; 95% CI: 0.163-0.670). These two groups were also markedly different with respect to the clinical course of the cervical lesions, in the frequency of progressive disease (determined by PAP smear) was higher in HIV-positive group (12/89) than in HIV-negative women (2/52) (OR 3.506; 95% CI 0.816-15.055) (P = 0.055), in whom the disease regressed more frequently than in HIV-positive women (13.5% vs 7.9%) (OR 0.584; 95% CI 0.217-1.573). Using (1) HPV-positivity, (2) oncogenic HPV-type and (3) significant PAP smear abnormality at the end of follow-up as outcome measures, (1) was significantly (P < 0.001) predicted by the following variables in univariate analysis: age, mode of contraception, CD4 count, and HIV-positivity. The significant predictors of (2) were age and mode of contraception. The outcome measure (3) was significantly predicted by CD4 count, PAP smear abnormality and PCR status at entry. In the multivariate analysis, the significant independent predictive factors for HPV-positivity proved to be only the HIV status (P < 0.001), and PCR status at entry, p53 polymorphism at aa-72, oncogenic HPV type and significant PAP smear at entry remained independent predictors, with the significance level of P < 0.05. None of the significant predictors of oncogenic HPV type in univariate analysis retained their independent value in multivariate analysis. Oncogenic HPV type at entry proved to be an independent predictor of significant PAP smear (P < 0.05). The present results indicate that HIV-infected women, even on highly active antiretroviral therapy, demonstrate a more aggressive clinical course of cervical HPV infections, and fail to eradicate the disease more frequently than HIV-negative women. This persistence of HPV-positivity, oncogenic HPV type and significant PAP smear abnormality can be predicted by the results of PAP test and HPV typing in univariate analyses, and partly retain their independent predictive value also in multivariate analysis. Clearly, in addition to regular monitoring by PAP smear, HPV testing for the oncogenic HPV types seems to provide additional prognostic information in the management of cervical lesions in HIV-infected women.

AIDS-Related Opportunistic Infections↗
PubMed2002

Diffuse large B-cell lymphoma: one or more entities? Present controversies and possible tools for its subclassification.

Diffuse large B-cell lymphoma (DLBCL) is the commonest type of lymphoid tumour world-wide. This category was included both in the REAL and WHO Classification aiming to lump together all malignant lymphomas characterized by the large size of the neoplastic cells, B-cell derivation, aggressive clinical presentation, and the need for highly effective chemotherapy regimens. These tumours are detected as primary or secondary forms both at the nodal and extranodal levels, in immunocompetent hosts as well as in patients with different types of immunosuppression. They display a significant variability in terms of cell morphology and clinical findings, which justifies the identification of variants and subtypes. Among the latter, the primary mediastinal one does actually correspond to a distinct clinicopathological entity. Immunophenotypic, tissue microarray and molecular studies underline the extreme heterogeneity of DLBCLs and suggest a subclassification of the tumour, based on the identification of different pathogenic pathways, which might have much greater relevance than pure morphology for precise prognostic previsions and adoption of ad hoc therapies. The more recent acquisitions on the pathobiology of DLBCLs are reviewed in the light of the authors' experience, aiming to contribute to the existing debate on the topic.

Animals↗
PubMed2002

Hodgkin's lymphoma: the pathologist's viewpoint.

Despite its well known histological and clinical features, Hodgkin's lymphoma (HL) has recently been the object of intense research activity, leading to a better understanding of its phenotype, molecular characteristics, histogenesis, and possible mechanisms of lymphomagenesis. There is complete consensus on the B cell derivation of the tumour in most cases, and on the relevance of Epstein-Barr virus infection and defective cytokinesis in at least a proportion of patients. The REAL/WHO classification recognises a basic distinction between lymphocyte predominance HL (LP-HL) and classic HL (CHL), reflecting the differences in clinical presentation and behaviour, morphology, phenotype, and molecular features. CHL has been classified into four subtypes: lymphocyte rich, nodular sclerosing, with mixed cellularity, and lymphocyte depleted. The borders between CHL and anaplastic large cell lymphoma have become sharper, whereas those between LP-HL and T cell rich B cell lymphoma remain ill defined. Treatments adjusted to the pathobiological characteristics of the tumour in at risk patients have been proposed and are on the way to being applied.

Diagnosis, Differential↗
PubMed2002

p53 mutation in breast cancer. Correlation with cell kinetics and cell of origin.

AIM: Several studies have investigated the expression of the cytokeratins (CKs), vimentin, the epithelial growth factor receptor (EGFR), the oestrogen receptor (ER), and the progesterone receptor (PgR), in breast cancer, but no study has directly compared p53 mutations with these phenotypic and differentiation markers in the same case. The present study was designed to provide some of this information. METHODS: The expression of the p53 and bcl-2 proteins was evaluated by immunohistochemistry in relation to phenotypic characteristics and cellular kinetic parameters (mitotic index and apoptotic index) in 37 cases of ductal carcinoma in situ (DCIS) and 27 cases of infiltrating ductal carcinoma (IDC) of the breast. In addition, p53 gene mutation was examined by polymerase chain reaction single strand conformation polymorphism analysis (SSCP). RESULTS: Thirteen cases (eight DCIS and five IDC) showed expression of CK8, CK14, CK18, vimentin, and EGFR, consistent with a stem cell phenotype, whereas 44 cases (27 DCIS and 17 IDC) showed expression of CK8 and CK1, weak or negative expression of CK18, but were negative for vimentin and EGFR, consistent with a luminal cell phenotype. DCIS and IDC cases with a stem cell phenotype were ER/PgR negative and intermediately or poorly differentiated. In contrast, the cases with luminal cell phenotype were ER/PgR positive and well or intermediately differentiated. In addition, intermediately or poorly differentiated cases with a stem cell phenotype showed higher proliferative activity (per cent of MIB-l positive cells) than did intermediately or well differentiated cases with a luminal cell phenotype. Both DCIS and IDC cases with a stem cell phenotype were p53 positive and bcl-2 negative by immunohistochemistry. In IDC, p53 expression was associated with a reduction of both mitotic index and apoptotic index compared with DCIS. Most of the tumours showing a more differentiated phenotype (luminal) were p53 negative and bcl-2 positive. In these cases, cell kinetic parameters increased from DCIS to IDC. These data suggest the existence of subsets of DCIS and IDC that, because of their phenotypic characteristics, could be derived from subpopulations of normal breast cells having different control mechanisms of cell proliferation and neoplastic progression. CONCLUSIONS: These results are compatible with the hypothesis that the phenotype of the cell of origin constrains both tumour phenotype and the choice of genetic events; however, the occurrence of p53 mutants by chance during neoplastic transformation cannot be excluded.

Adult↗
PubMed2002

Cell kinetics and cell cycle regulation in lymphomas.

The proliferative indices of non-Hodgkin's lymphomas are useful prognostic indicators and provide information independent of other histological and clinical variables. However, proliferative indices alone do not suffice to characterise cell growth. A high cell production rate may be compensated, almost or fully, by a high cell deletion rate. A re-evaluation of parameters of cell kinetics in view of our increasing knowledge of the molecular pathways of cell cycle control may provide more prognostic information for the management of patients with malignant lymphomas.

Apoptosis↗
PubMed2001

RB2/p130 gene-enhanced expression down-regulates vascular endothelial growth factor expression and inhibits angiogenesis in vivo.

Angiogenesis is an essential step in the progression of tumor formation and development. The switch to an angiogenetic phenotype can occur as a distinct step before progression to a neoplastic phenotype and is linked to genetic changes such as mutations in key cell cycle regulatory genes. The pathogenesis of the angiogenetic phenotype may involve the inactivation of tumor suppressor genes such as the "guardian of the genome," p53, and the cyclin-dependent kinase inhibitor p16. Retinoblastoma family member RB2/p130 encodes a cell cycle regulatory protein and has been found mutated in different tumor types. Overexpression of RB2/p130 not only suppresses tumor formation in nude mice but also causes regression of established tumor grafts, suggesting that RB2/p130 may modulate the angiogenetic balance. We found that induction of RB2/p130 expression using a tetracycline-regulated gene expression system as well as retroviral and adenoviral-mediated gene delivery inhibited angiogenesis in vivo. This correlated with pRb2/p130-mediated down-regulation of vascular endothelial growth factor protein expression both in vitro and in vivo.

Animals↗