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M Pignatelli

Publications and source records attributed to M Pignatelli.

At least 91 records · Page 5Linked to original sources
PubMed1995

E-cadherin expression in bladder cancer using formalin-fixed, paraffin-embedded tissues: correlation with histopathological grade, tumour stage and survival.

To determine the potential prognostic value of epithelial cadherin (E-cadherin), a Ca(2+)-dependent cell-cell adhesion molecule, we have analysed its immunoreactivity and cellular localisation in 67 transitional cell carcinomas (TCC) using an avidin-biotin immunoperoxidase technique on formalin-fixed, paraffin-embedded tissues. These results were correlated with histopathological grade, tumour stage, presence of metastases and survival. In addition, 10 cystitis and 11 normal bladder biopsies were evaluated as controls. E-cadherin was expressed in a normal membranous pattern in all normal and 7 of 10 cystitis biopsies. Loss of normal surface E-cadherin expression was found in 3 of 15 superficial tumours and in 48 of 52 invasive cancers. Abnormal immunoreactivity was strictly related to tumour differentiation and stage. Fifteen of 20 well-differentiated (grade I) tumours showed preserved membranous E-cadherin immunoreactivity, while 46 of 47 moderate and poorly differentiated tumours (grades II and III) demonstrated abnormal staining patterns. Loss of membranous E-cadherin immunoreactivity was also associated with advanced tumour stage. There was a significantly higher 5-year survival rate for patients with preserved membranous staining compared with patients with abnormal staining.

Cadherins↗
PubMed1995

Organisation and gel contraction by human colonic carcinoma (HCA-7) sublines grown in 3-dimensional collagen gel.

The role of cell-matrix interactions in controlling phenotypic heterogeneity in human colonic carcinoma sublines has been investigated. Four cell lines (colony 1, colony 3, colony 6 and colony 30) previously isolated from a single human colonic carcinoma cell line, HCA-7, were grown in 3-dimensional collagen gels. In collagen, the growth of the 4 sublines ranged from well-organised glandular structures (colony 30) to elongated branching structures (colony 3). The capability of cells to organise into glandular structures in collagen correlated with the degree of differentiation observed in their xenografts. Certain sublines, most notably colony 3, were able to contract the collagen gel. Gel contraction could be partially inhibited by a function-blocking antibody directed to the alpha 2 integrin chain but not by an antibody directed to the alpha 3 integrin chain demonstrating a role for alpha 2 integrin in the contraction process. In addition, colony 3 cultures treated with the function-blocking alpha 2 antibody formed more compact structures with limited outgrowth, suggesting a role for alpha 2 integrin in cell migration. Gel contraction and cell migration in collagen gel was largely restricted to 1 subline, colony 3. The subsequent demonstration that alpha 2 integrin is involved in both of these processes suggests that integrin expression and function has a role in generating the phenotypic heterogeneity exhibited by these cell lines.

Collagen↗
PubMed1995

Altered expression and function of E-cadherin in cervical intraepithelial neoplasia and invasive squamous cell carcinoma.

HECD-1 monoclonal antibody has been used to localize E-cadherin, a calcium-dependent cell-cell adhesion molecule, in microwave-treated, paraffin-embedded sections from 53 cases of cervical intraepithelial neoplasia (CIN) (11 CIN I, 22 CIN II, and 20 CIN III), 16 invasive cervical squamous cell carcinomas, and seven metastases. In normal cervix, E-cadherin was expressed on the cell membrane of basal and parabasal cells. Cytoplasmic staining was present in occasional basal cells only. In CIN, the presence and localization of cytoplasmic E-cadherin were found to be significantly correlated with the grade of the CIN lesion. In squamous cell carcinomas, reduced membranous and increased cytoplasmic staining was seen with worsening differentiation. Loss of membranous E-cadherin expression was also detected in 4/7 metastatic deposits. E-cadherin expression (120 kD form on Western blotting) was seen in human cervical carcinoma cell lines (HT3, ME180, C4I, Caski) that maintained the ability to aggregate in a homotypic adhesion assay and showed a typical epithelial morphology. E-cadherin-negative cell lines (Hela, SiHa, C33A) did not show adhesion. HOG-1 was the only E-cadherin-negative cell line which showed a significant degree of cell-cell aggregation. These data indicate that loss of membranous E-cadherin expression may represent one of the abnormalities underlying loss of cell polarity and differentiation which characterize CIN and invasive cervical cancer.

Blotting, Western↗
PubMed1995

Expression of integrin subunits in the human infant breast correlates with morphogenesis and differentiation.

Integrins are widely expressed on normal tissues and their function is considered critical directly or indirectly with the control of cell growth and differentiation. Also, they are likely to play a crucial role in cell-matrix interactions during development. As the human breast develops after birth, it provides a rare opportunity in which to study human organogenesis. We have examined the distribution of integrins in the human infant breast with the aim of elucidating the possible role of these molecules in morphogenesis and differentiation. Necropsy breast specimens from six male and eight female infants, ranging in age from 1 day to 9 months, were used in this study. Cryostat sections were stained by the avidin-biotin complex technique, using a panel of monoclonal antibodies (MAbs) which recognize beta 1, alpha 2, alpha 6, beta 4, alpha v, and alpha v beta 3 integrin chains, which are candidate molecules for a role in mammory morphogenesis. MAbs to beta 1 (DH12) and alpha 2 (HAS3) showed positive membrane and cytoplasmic staining of basal cells and luminal epithelial cells. In addition, positive staining for the beta 1 integrin chain was found on fibroblasts. A MAb which recognizes the alpha 6 chain (MP4F10) showed positive staining of the basal cells and heterogeneous staining of the luminal epithelial cells, whilst beta 4 chain (439-9B) showed positive staining in the basement membrane domain of the basal cells with no staining of the luminal epithelial cells. There was a positive correlation between the intensity of expression and the structural development of the ductal system, with integrin expression reduced or absent in the end buds and lateral buds.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗
PubMed1995

Human spasmolytic polypeptide is a cytoprotective agent that stimulates cell migration.

BACKGROUND/AIMS: Gastric epithelium is attacked by acid, pepsin, and ingested agents. When a mucosal lesion occurs, the defect is rapidly closed by cell migration. Because spasmolytic polypeptide is rapidly produced at sites of injury, we postulated that human spasmolytic polypeptide (hSP) was important in mucosal repair. Recombinant hSP was used to test this hypothesis. METHODS: The ulcer healing effect of various doses of hSP administered orally and subcutaneously was examined using an indomethacin (20 mg/kg) restraint rat model of gastric damage. Stability of hSP in gastrointestinal juice was determined using size-exclusion chromatography. The effect of hSP on migration of human colonic carcinoma cell lines HT29 and SW480 was determined using collagen gel invasion and wounded monolayer assays. Proliferation was assessed using [3H]thymidine incorporation and toluidine blue staining. RESULTS: Infusions of hSP at 25 and 50 micrograms.kg-1.h-1 subcutaneously decreased gastric damage by about 50% (P < 0.01) without changing acid secretion. Oral hSP was ineffective. hSP was stable in gastrointestinal juice. hSP stimulated migration of HT29 cells but did not affect proliferation and had no effect on SW480 cells. CONCLUSIONS: hSP may play a key role in the early stages of mucosal repair by stimulating the initial re-epithelialization by cell migration.

Animals↗
PubMed1995

Type-1 growth factor receptors in pancreatic and gastrointestinal neoplasia.

Altered expression of type-1 growth factor receptors and their ligands is frequently found in both benign and malignant neoplasms of the gastrointestinal tract and its adnexae, and may contribute to the establishment and progression of these tumours. Upregulated expression of both receptors and ligands to form potential autocrine loops is associated with poor prognosis in some tumour types. Overexpression of the type-1 receptors may be exploited for novel therapies including genetically directed enzyme therapy and receptor-mediated drug delivery.

Cell Line↗
PubMed1995

Integrins in tumour development and spread.

The study of integrin receptor expression and function in carcinomas will undoubtedly increase our understanding of the malignant process and clarify the relative importance of the numerous alterations that are identified. Whether this will lead to direct clinical applications is not clear at present, but it will certainly alter our approach to the evaluation of cancer treatment. The more immediate search for prognostic indicators and metastatic site preference in tumours expressing a particular integrin profile is partly hampered by the small numbers of cases studied in most series, where observed trends in tumour subsets barely achieve significance. Perhaps the next phase should be to evaluate promising approaches in large multicentre studies to establish the relative importance of these trends in tumour prognosis and response to treatment, preferably by developing reagents that will permit the demonstration of integrins in routinely processed archival material from human tumour specimens. Future developments in therapy may depend on the knowledge that may emerge from such work.

Animals↗
PubMed1995

Proliferating cell nuclear antigen in benign breast diseases.

The expression of PCNA was examined by immunohistochemistry on 95 formalin-fixed breast surgical specimens. Seventy-four were benign breast disease, 3 atypical hyperplasia; 5 in situ carcinoma; 13 invasive carcinoma. Forty-two percent of benign breast disease, 75% of atypical hyperplasia/in situ carcinoma and 92% of invasive breast carcinoma expressed PCNA nuclear staining. Forty percent of cysts, 15.78% of sclerosing adenosis, 22.22% of adenosis, and 17.39% of epitheliosis expressed low cyclin protein levels (PCNA score I, < 18%); 20% of cysts, 31.57% of sclerosing adenosis, 5.55% of adenosis and 43.47% of epitheliosis expressed moderate levels (PCNA score II, 18 to 50%); whereas 50% of atypical hyperplasia/in situ carcinoma and 54% of invasive breast carcinoma contained high levels (PCNA score III, > 50%). This study on PCNA/cyclin localization suggests that PCNA is an early indicator of ongoing cellular proliferation.

Breast↗
PubMed1994

TGF-alpha can act as morphogen and/or mitogen in a colon-cancer cell line.

Transforming growth factor alpha (TGF-alpha) has multifunctional biological effects on a variety of mesenchymal and epithelial cells. It is a potent mitogen for a number of normal and transformed cell types, regulates extracellular matrix (ECM) production and promotes breast, kidney and lung morphogenesis. To clarify the role of ECM proteins in the morphogenetic and mitogenic effects of TGF-alpha, we have used a human colon carcinoma cell line (SW1222) which expresses EGF receptor. Here we show that TGF-alpha at 1 ng/ml increases the proliferation of SW1222 cells, but only when they are cultured on plastic rather than collagen-coated plates. Higher concentrations of TGF-alpha (10 ng/ml) did not increase cell proliferation but significantly enhanced the crypt-like glandular differentiation when cells were grown in 3-dimensional collagen gel (p = 0.027). These effects were accompanied by increased expression of alpha 2 beta 1 and alpha 3 beta 1 integrin molecules, which are receptors for extracellular matrix proteins, and by a statistically significant increase in binding of SW1222 cells to type-1 collagen. The effects of TGF-alpha both on binding to type-1 collagen and on morphological differentiation in 3-dimensional collagen gel were inhibited by monoclonal antibodies recognizing the alpha 2 beta 1 integrin. These data indicate that the morphogenetic or mitogenic activities of TGF-alpha are critically dependent on cellular interactions with extracellular matrix proteins and are primarily mediated by the alpha 2 beta 1 integrin receptor. Inappropriate expression of this growth factor, seen in tumours whose cell-matrix interactions are greatly impaired, could have deleterious effects on the maintenance of normal tissue architecture and growth control.

Antibodies, Monoclonal↗
PubMed1994

Loss of membranous E-cadherin expression in pancreatic cancer: correlation with lymph node metastasis, high grade, and advanced stage.

Epithelial cadherin (E-cadherin) is a Ca(2+)-dependent cell-cell adhesion molecule that connects cells via homotypic interactions. Its function is critical in the induction and maintenance of cell polarity and differentiation, and its loss of downregulation is associated with an invasive and poorly differentiated phenotype in colon and other tumors. We have used an avidin-biotin immunoperoxidase technique to localize E-cadherin in microwave-treated, paraffin-embedded sections from 36 patients with pancreatic adenocarcinomas. E-cadherin was expressed by normal ductal and acinar cells with typical membranous staining at the intercellular junctions. Loss of normal surface E-cadherin expression was found in 19/36 (53 per cent) tumours compared to the adjacent normal ductal cells. Abnormal E-cadherin expression was found more frequently in poorly differentiated (grade III) (6/7, 86 per cent) than in well-differentiated tumors (grade I) (4/14, 28 per cent) (P = 0.012). Membranous E-cadherin expression was also lost more frequently in primary tumours with lymph node (stage III) (14/23, 61 per cent) and distant metastasis (stage IV) (2/2, 100 per cent) compared with 3/11 (27 per cent) lymph node-negative tumours (stage I) (P = 0.043). In conclusions, our data indicate that loss of membranous E-cadherin expression is associated with high grade and advanced stage in pancreatic cancer.

Adenocarcinoma↗
PubMed1994

Adhesion molecules: novel molecular tools in tumor pathology.

Cell adhesion is a key process, elementary in the establishment of tissue architecture and differentiation. In neoplasia, in which there is a disruption of tissue architecture and a derangement in differentiation, it has been postulated that changes in cell-cell and cell-matrix interactions account for the ability of cancer cells to transgress normal tissue boundaries and disperse to distant sites. Complex and coordinated reductions and increases in adhesion have been proposed to be necessary for tumor invasion and metastasis. This hypothesis has fueled the interest of cancer research teams to evaluate the expression of various adhesion molecules in a wide range of human malignancies in the hope of pinpointing some of the cell adhesion alterations underlying tumor behavior. To date, a multitude of transmembrane glycoproteins, including cell-cell adhesion molecules (CAMs) and cell-matrix or substratum adhesion molecules (SAMs), have been identified; their structure, molecular genetics, and biochemistry have been elucidated, and we are beginning to understand their normal function. A few of these, on the basis of current evidence, seem to be promising candidate molecules for a role in neoplasia. This article aims to summarize recent developments in this field of adhesion research as well as the clinical applications in diagnostic pathology arising from it. First, by way of introduction, a summary of the biochemical and functional characterization of each family of adhesion receptors will be presented, followed by a presentation of the experimental data implicating them in the control of invasion, metastasis, and differentiation.

Biomarkers, Tumor↗
PubMed1994

Cell adhesion molecules in oesophageal epithelium.

The distribution of a range of integrins, E-cadherin, and carcino-embryonic antigen (CEA) like molecules in normal human oesophageal epithelium was investigated immunohistochemically on frozen sections of endoscopic biopsy specimens. The integrin subunits alpha 2, alpha 3, alpha 6, alpha v, beta 1, and beta 5 were expressed throughout the epithelium. There was strong expression of alpha 2, alpha 3, and beta 1 subunits in the basal cell layer and for all the subunits studied the intensity of the staining decreased as cells moved towards the lumen. The heterodimer alpha v beta 3 was expressed weakly in the basal aspect of the basal cell layer only. The CEA molecules were not present in the basal cells layer but there was weak expression in the prickle cell layer and strong positivity in the mature functional layer. E-cadherin was found throughout the epithelium but was weakly expressed at the basal aspect of the basal cells layer and showed strong positivity in the prickle cell and squamous cell layers. These results indicate that cell-cell (E-cadherin, CEA) and cell-matrix (integrins) adhesion molecules show a well defined spatial pattern of immunoreactivity in the oesophageal mucosa and may play a part in the maintenance of normal tissue architecture and physiological homeostasis.

Cadherins↗
PubMed1993

Beta 1 and beta 4 integrin expression in methacarn and formalin-fixed material from in situ ductal carcinoma of the breast.

The integrins are alpha beta heterodimeric transmembrane proteins mediating cell-substratum as well as cell-cell interactions. Previous distribution studies on integrin expression have been limited by the requirement of cryostat sectioned tissues, and consequent poor resolution. We have examined 40 examples of ductal carcinoma in situ (DCIS) for the expression of both beta 1 and beta 4 integrin chains. These showed strong polarized membrane staining of residual myoepithelial cells (correlating with expression of smooth muscle specific actin) and of the basement membrane region with beta 1 and beta 4 antibodies respectively. In 12 out of 40 cases, the DCIS was negative for the beta 1 chain and a variable pattern of reactivity was seen in the remaining cases. The beta 4 chain was detected focally and weakly in the tumour cells of 7/40 DCIS and strongly in one; all of these cases were also positive for the beta 1 chain. Of the 22 cases where co-existent invasion was present, the infiltrating component showed either a similar degree or a diminution of the extent of immunostaining when compared with the in situ component; only one showed enhanced staining (beta 1 only). This study demonstrates that two of the main beta chains, beta 1 and beta 4, can be effectively demonstrated on methacarn and cold (4 degrees C) formalin-fixed tissues by avidin-biotin indirect immunoperoxidase staining and that the results are similar to those achieved using frozen tissue.

Acetates↗
PubMed1993

Loss of cell-cell and cell-matrix adhesion molecules in colorectal cancer.

Adhesion molecules are thought to play a vital role in the induction and maintenance of tissue differentiation and their loss or down-regulation has been implicated in the neoplastic process. Recent studies have shown that the morphoregulatory activities are a consequence of interactive processes between several cell adhesion molecules rather than the function of a single molecule. Therefore, we have investigated a panel of adhesion molecules including members of the integrin, cadherin and immunoglobin superfamily in colorectal cancer. Twenty-eight consecutive colorectal adenocarcinomas were stained using an avidin-biotin indirect immunoperoxidase technique. Our results showed a consistent loss of the alpha 2 and beta 1 integrin subunits (21/28 = 75% and 22/28 = 78.6% respectively) and a decrease in expression of E-cadherin in 5/5 poorly differentiated adenocarcinomas. Carcinoembryonic antigen expression was preserved but with basolateral accentuation seen in tumours. There was no statistical correlation with Dukes' stage. These results provide further evidence that in colorectal cancer there is a widespread deregulated expression of cell-cell and cell-matrix adhesion molecules. Changes in the expression and function of adhesion molecules which regulate growth and differentiation may play a role in the behaviour of colorectal cancer.

Adenocarcinoma↗
PubMed1993

Transforming growth factor-beta distribution in basal cell carcinomas: relationship to proliferation index.

Transforming growth factor-beta (TGF-beta) distribution in basal cell carcinomas (BCCs) was studied using polyclonal antibodies recognizing intra- (precursor) and extracellular (activated) forms (LC 1-30 and CC 1-30), and compared with an index of cell proliferation (PCNA immunoreactivity). Intracellular TGF-beta is found in suprabasal keratinocytes and the outer root sheath. Extracellular TGF-beta is largely absent from normal skin, but is abundant in the intracellular spaces of hyperplastic epidermis overlying BCCs. Twenty-five of 29 BCCs showed increased extracellular TGF-beta in the desmoplastic stroma, with intercellular staining in nine of these. Intracellular TGF-beta was present in fibroblasts and endothelial cells, although only 17 of 29 BCCs were positive, predominantly in central cells showing apparent maturation. Little correlation was seen between the degree of staining of tumour cells and the distribution of extracellular TGF-beta. PCNA immunoreactivity was greater in BCCs compared with normal epidermis in 24 of 37 cases (P = 0.005), and was concentrated on the periphery of nodular BCCs. Strongest stromal reactivity for TGF-beta and maximal PCNA index also showed a significant correlation (P = 0.023). This study demonstrated abundant TGF-beta in the active stroma around BCCs, which may account for many of the morphological and functional characteristics of this tumour, but which may be a product of stromal rather than tumour cells.

Antigens, Neoplasm↗