Biomedical subjects

G W Stamp

Publications and source records attributed to G W Stamp.

At least 37 records · Page 2Linked to original sources

PubMed1997

Expression of bcl-2 in bladder neoplasms is a cell lineage associated and p53-independent event.

AIMS: To investigate bcl-2 and p53 protein expression in hyperplastic, metaplastic and neoplastic epithelia of the urinary bladder in relation to cell lineages (transitional versus glandular epithelia). METHODS: Formalin fixed, paraffin wax embedded archival tissue blocks of 29 transitional cell carcinomas (TCC), 11 adenocarcinomas, five specimens of cystitis glandularis, four papillomas, and seven samples of morphologically normal bladder mucosa were examined immunohistochemically with antibodies specific to bcl-2 and p53. Consecutive sections were used to assess co-expression of the two proteins. RESULTS: bcl-2 protein was expressed heterogeneously in basal cells of the normal transitional epithelium, whereas p53 was rarely detectable in either normal or hyperplastic epithelium. Of the 29 TCCs, 20 (69%) expressed immunodetectable p53 which was positively associated with grade. In contrast, bcl-2 was detected in four (14%) TCCs and its expression was not associated with grade. bcl-2 was expressed constitutively in all five specimens of cystitis glandularis and in all adenocarcinomas; p53 was co-expressed in most of the latter. There was no association between bcl-2 and p53 protein expression in the TCCs. Expression of bcl-2 protein correlated negatively with grade of adenocarcinoma. CONCLUSION: In bladder adenocarcinomas, bcl-2 expression correlated negatively with tumour grade whereas p53 was associated positively with tumour grade. The association of bcl-2 with cystitis glandularis and adenocarcinoma but not TCC suggests that it may be involved in triggering a lineage switch converting transitional epithelium to a glandular phenotype.

Adenocarcinoma↗

PubMed1997

Quantitative assessment of the leukocyte infiltrate in ovarian cancer and its relationship to the expression of C-C chemokines.

We have defined the host leukocyte infiltrate in epithelial ovarian tumors and related this to the expression of C-C chemokines. Immunohistochemical analysis of 20 paraffin-embedded biopsies showed that the infiltrate was primarily composed of CD68+ macrophages and CD8+/CD45RO+ T cells (median values, 3700 cells/mm3 and 2200 cells/mm3, respectively). Natural killer cells, B cells, and mast cells occurred in lower numbers (median values, 0 to 200 cells/mm3). Eosinophils were rarely seen and neutrophils were mainly confined to blood vessels. More infiltrating cells were found in stromal than in tumor areas. Only macrophages occurred in significant numbers in areas of necrosis (P < 0.0005). Using in situ hybridization to mRNA, we examined expression of the chemokines MCP-1, MIP-1 alpha, MIP-1 beta, and RANTES. MCP-1 and MIP-1 alpha were expressed by significantly more cells than MIP-1 beta and RANTES (P < 0.005). In tumor epithelial areas, the predominant chemokine was MCP-1. MCP-1 and MIP-1 alpha were the predominant stromal chemokines. A significant correlation was found between the total number of CD8+ T cells and the number of cells expressing MCP-1 (rs = 0.63 and P < 0.003, respectively) and between the CD8+ population and RANTES-expressing cells (rs = 0.6 and P < 0.003). A correlation was also found between CD68+ macrophages and the number of cells expressing MCP-1 (rs = 0.50 and P = 0.026). We suggest that MCP-1 may be responsible for the leukocyte infiltrate in ovarian carcinomas, but the expression of other chemokines may determine its exact nature.

Carcinoma↗

PubMed1996

Second messenger up-regulation of androgen receptor gene transcription is absent in androgen insensitive human prostatic carcinoma cell lines, PC-3 and DU-145.

A theoretical pathway of transcriptional regulation of the androgen receptor (AR) gene is via a cAMP response element (CRE) present in its promoter region (-508 to -501). After 20 h of stimulation with 8-bromo-cAMP, AR mRNA was upregulated in LNCaP but not in either PC-3 or DU-145 cell lines. We have demonstrated that the level of CRE binding protein (CREB) was the same in all cell lines and that the putative AR-CRE forms specific and compatible protein interactions with CREB. The ability to regulate AR gene transcription via the second messenger pathway is lost in the PC-3 and DU-145 cell lines. This may be an important primary mechanism of androgen insensitivity in prostate cancer.

Animals↗

PubMed1996

Expression of the type 1 tyrosine kinase growth factor receptors EGF receptor, c-erbB2 and c-erbB3 in bladder cancer.

Expression of the c-erbB3 protein was determined in transitional cell carcinoma of the bladder by immunohistochemistry. Strong membrane staining was observed in 10 per cent of cases (7/70) and cytoplasmic and membrane overexpression in 20 per cent (14/70). Overexpression of the epidermal growth factor (EGF) receptor (36 per cent, 25/70) and c-erbB2 proteins (9 per cent 6/70) was determined in the same series of cases. c-erbB3 overexpression was positively correlated with EGF receptor expression (P < 0.025) but appeared to be inversely associated with c-erbB2 overexpression.

Biomarkers, Tumor↗

PubMed1996

Characterization of monoclonal antibodies raised to C-terminal peptides of pS2: a major trefoil peptide and motility factor expressed in adenocarcinomas and regions of mucosal injury.

Two novel monoclonal antibodies, GE1 and GE2 raised against the C-terminal 31 and 28 amino acids of the estrogen-inducible trefoil peptide pS2, are described. Both antibodies are able to detect pS2 in formalin-fixed, paraffin-embedded tissues. Conditions are presented under which pS2 can be shown in cell lines by immunohistochemistry that has previously been problematic. The antibodies can specifically show the presence of pS2 in cell lysates by Western blotting and immunoprecipitation. In the form of an affinity column, the GE1 monoclonal antibody can be used to purify pS2 from MCF-7 supernatants. The eluted peptide from the GE1 affinity column shows a single band at 6,600 Da (predicted size for pS2) on Western blotting. These antibodies are valuable reagents in the analysis of the role of trefoil peptides in the maintenance of mucosal integrity, and may have applications in the assessment of pS2 expression in chronic gastrointestinal ulceration and adenocarcinomas that secrete pS2, where it may serve as a prognostic marker.

Adenocarcinoma↗

PubMed1996

Expression of collagenase (MMP2), stromelysin (MMP3) and tissue inhibitor of the metalloproteinases (TIMP1) in pancreatic and ampullary disease.

It is now recognised that epithelial-stromal interactions are important in a wide range of disease processes including neoplasia and inflammation. Metalloproteinases are central to matrix degradation and remodelling, which are key events in tumour invasion and metastasis and may also be involved in tissue changes occurring in chronic inflammation. Immunohistochemistry was performed on sections from 50 patients with pancreatic cancer (n = 27), ampullary cancer (n = 12), low bile duct cancer (n = 3), neuroendocrine tumours (n = 3) and chronic pancreatitis (n = 5), using antibodies raised against collagenase (MMP2), stromelysin (MMP3) and tissue inhibitor of metalloproteinase (TIMP1) and developed using the avidin-biotin complex method. Abundance of MMP2, MMP3 and TIMP1 was greater in pancreatic and ampullary cancer than any other pathology and immunoreactivity in the malignant epithelial cells in pancreatic and ampullary cancer was greater than in the stromal tissues (in pancreatic cancer: MMP2 100% vs 37%, MMP3 93% vs 15%, TIMP1 93% vs 4%, P < 0.0001). There were strong correlations between the immunoreactivity of the two antibodies for MMP2 (P < 0.0001), between MMP2 and TIMP1 (P < 0.0001) and between MMP3 and TIMP1 (P < 0.0001). The immunoreactivity for TIMP1 in pancreatic and ampullary cancers with lymph node metastases was significantly less compared with those cases without lymph node metastases (P < 0.02) and there was an association between increased immunoreactivity for MMP2 and the degree of tumour differentiation (P < 0.01). The results implicate MMP2, MMP3 and TIMP1 in the invasive phenotype of pancreatic and ampullary cancer.

Ampulla of Vater↗

PubMed1996

Morphological interactions of human first trimester placental villi co-cultured with decidual explants.

Abnormalities of pregnancy such as pre-eclampsia and intrauterine growth retardation are characterized by shallow trophoblastic invasion of the placental bed, the precise molecular pathophysiology of which remains to be fully elucidated. An in-vitro model involving a co-culture of first trimester placental villi and decidua parietalis explants (of 8-12 weeks gestation) was developed and used to characterize the migration and local invasion of trophoblast cells. Trophoblast proliferation (confirmed by Ki-67 immunostaining), differentiation and loose attachment of placental villi to the underlying decidual epithelium or stroma occurred within the first 24 h of co-culture. This was followed by erosion of the syncytial layer of the placental villi and commencement of a progressive cytotrophoblast invasion after 48 h of co-culture, which continued until 120 h, when the experiments were terminated. E-cadherin was expressed at the interfaces between trophoblast cells within the villi, but expression of this adhesion molecule seemed to be down-regulated in the invasive trophoblast cells. Our results suggest that the model could be useful in investigating the factors that control early human placentation and the feto-maternal interface.

Antibodies, Monoclonal↗

PubMed1996

Establishment and characterisation of two cell lines derived from a primary adenocarcinoma of the duodenum.

Aims-To establish two cell lines from a primary duodenal adenocarcinoma; to describe the morphological, growth, ploidy, and immunophenotypic characteristics of these cell lines.Methods-The cell lines, designated DAC/S and DAC/E, were characterised using both in vitro and in vivo cell culture techniques, light and electron microscopy, immunocytochemistry, and FACS analyses.Results-Both cell lines have an epithelial origin, are aneuploid and display characteristics of transformed cells. The cell lines differ from each other in morphology, doubling time and serum requirements. These cell lines are anchorage dependent and do not grow in nude mice.Conclusions-DAC/S and DAC/E cell lines are derived from neoplastic epithelium and could provide in vitro model systems for future investigations of the cell and molecular biology of duodenal neoplasia.

Journal Article↗

PubMed1996

c-erbB3 protein expression in ovarian cancer.

Aims-To study the prevalence of overexpression of c-erbB3 growth factor receptor in ovarian carcinomas and to analyse its relation to histological subtype, stage and grade of the tumours.Methods-Ninety eight ovarian carcinomas were evaluated immunohistochemically using the RTJ1 monoclonal antibody raised against a synthetic peptide, the sequence of which was derived from the cytoplasmic domain of the c-erbB3 protein.Results-Of the tumours, 16% (16/98) overexpressed c-erbB3 protein relative to normal ovarian epithelium, whereas 22% (22/98) were completely negative. There was a statistically significant association between overexpression and well differentiated grade.Conclusions-These findings suggest that c-erbB3 protein overexpression occurs in a significant proportion of ovarian cancers and is correlated with differentiation. Overexpression may merit further investigation as a potential prognostic indicator and as a target for new treatment.

Journal Article↗

PubMed1996

pS2 transfection of murine adenocarcinoma cell line 410.4 enhances dispersed growth pattern in a 3-D collagen gel.

We describe the first model system employing human pS2 gene transfer and expression in a non-pS2-expressing cell line, mouse mammary adenocarcinoma 410.4, in order to analyse the potential effect of human trefoil peptide pS2 in glandular epithelium. Two selected clones, AA4 and AD4, were established and shown to have incorporated the pS2 cDNA sequence into the genome, express pS2 containing transcript and produce the pS2 peptide. When grown in 3-D collagen gels both transfectants show striking morphological changes compared to the vector control clone (VA5). VA5 forms large cohesive spherical aggregates with rare coarse spicular outgrowths, accompanied by prominent hyalinised extracellular matrix deposition. pS2 transfectants form poorly cohesive, stellate colonies with very little or no matrix deposition, radiating long cords composed of single elongated cells, an effect previously observed in other cell lines with hepatocyte growth factor. pS2 transfection had no demonstrable effect on proliferation and this is not a morphogenetic phenomenon, as tubulogenesis is not seen. Motility assays suggest that the pS2 'dispersant' effect in collagen gels is due to an increase in cell motility. There were no measurable alterations in either E-cadherin expression or E-cadherin-dependent cell-cell aggregation. pS2 may play a role in maintenance and restitution of mucosal integrity by accelerating migration/dispersion.

Adenocarcinoma↗

PubMed1996

MUC1 expressed in PanC1 cells decreases adhesion to type 1 collagen but increases contraction in collagen lattices.

A subline of human pancreatic cells (PanC1) that expresses low levels of cytokeratins 8 and 18 but not MUC1 mucin was transfected with both 3.5-kb and 3.9-kb full-length MUC1 cDNA. The MUC1-positive clone expressing the larger mucin was shown to express increased levels of cytokeratins 8 and 18 compared with the parental line or vector controls. Growth of these MUC1-transfected cells in type I collagen gels produced marked gel contraction that could be significantly reduced by the synthetic peptide SRGDTG or by growth in serum and fibronectin-depleted media. Cellular binding to type I collagen was found to be reduced by two- to four-fold in cells expressing the MUC1 mucin, for which the greatest inhibition was observed in cells expressing the larger form. No difference in cellular binding to fibronectin was observed. From these data we conclude that the human MUC1 mucin modifies the differentiated state of human pancreatic cells by altering cytokeratin expression and reducing adhesion to type I collagen but paradoxically enhancing the cellular contractile phenotype, effects that appear to be mediated by integrin expression and/or function.

Adenocarcinoma↗

PubMed1996

Matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-2 expression and synthetic matrix metalloproteinase-2 inhibitor binding in ovarian carcinomas and tumor cell lines.

Enhanced matrix metalloproteinase-2 (MMP-2/72-kd type IV collagenase) action correlates with invasion in neoplasia. MMP-2 is inhibited in vivo by tissue inhibitors of metalloproteinases (TIMPs)-TIMP-1 and, especially, TIMP-2. A synthetic, biotinylated inhibitor specific for activated MMP-2 in solution phase, and immunohistochemistry were used to detect MMP-2 and TIMP-2 expression in cell lines and ovarian tumors and to analyze the surface-binding capacity of the inhibitors, which are potential therapeutic agents. Characterization of novel monoclonal antibodies to MMP-2 and TIMP-2 is described together with immunocytochemical staining of 83 paraffin-embedded ovarian tumors (67 malignant, 7 borderline, 9 benign) and 9 cell lines. Synthetic MMP-2 inhibitor binding under controlled conditions was visualized by immunofluorescence and avidin-biotin complex immunoperoxidase methods in cell lines and cryostat sections of ovarian tumors. MMP-2 and TIMP-2 showed heterogenous immunoreactivity, with enhanced staining on high-grade tumors, specifically at the invasive front and in vascular invasion. TIMP-2 immunoreactivity was maximal in malignant cell cytoplasm and less intense in desmoplastic fibroblasts. One monoclonal antibody to MMP-2 showed membrane immunoreactivity, apically polarized in benign and low-grade tumors but depolarized and strong in 37 of 44 cases of high-grade invasive tumors. Eleven of eighteen ovarian carcinomas and six of nine cell lines showed membrane localization of the synthetic inhibitor. Maximal binding occurred in the ovarian cell line OVCA 432 and the breast cell lines MCF 7 and MDA MB 435, all of which were immunoreactive for MMP-2. Cell lines propagated on type I collagen showed no enhancement in inhibitor binding. This study demonstrates cell surface binding of a synthetic MMP-2 inhibitor and provides new evidence of MMP-2 and TIMP-2 immunoreactivity in ovarian carcinomas and cell lines.

Amides↗

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

Changes in E-cadherin immunoreactivity in the adenoma-carcinoma sequence of the large bowel.

We have used an avidin-biotin immunoperoxidase technique to localise epithelial cadherin (E-cadherin), a calcium-dependent cell-cell adhesion molecule, in 107 paraffin-embedded sections from 93 patients consisting of 24 with colorectal adenoma, 55 with rectal carcinoma and 14 with liver metastases. The corresponding primary colorectal tumours were also studied in these cases. E-cadherin was expressed by normal colorectal epithelial cells with typical membranous staining at the intercellular junctions. Loss of normal membranous E-cadherin expression and presence of cytoplasmic staining were found frequently in adenomas larger than 1 cm (P < 0.01), with high grade dysplasia and villous histology (P < 0.01). In primary rectal cancers, loss of membranous expression correlated with high tumour grade. No correlation was seen with Dukes and Jass stage, local extramural spread and 5-year recurrence rate. Complete loss of membranous E-cadherin immunoreactivity was seen in 7/14 (50%) liver metastases in which 6/7 (86%) showed intense membranous E-cadherin immunoreactivity in the corresponding primary tumour. Our data indicate that changes in E-cadherin immunoreactivity and cellular localisation correlate with size, severe dysplasia in adenomas and tumour grade in carcinomas. However, there seems to be no correlation between loss of membranous E-cadherin immunoreactivity and the invasive and metastatic potential of the carcinomas.

Adenoma↗

PubMed1995

MDM2 overexpression is rare in ovarian carcinoma irrespective of TP53 mutation status.

Somatic mutations in TP53 are seen in many human cancers. In addition, the protein product of the wild-type TP53 can be sequestered by the protein MDM2 (murine double minute 2). This protein is commonly overexpressed in human sarcomas and gliomas, usually as a result of gene amplification. In this study, 43 ovarian carcinomas (OCs) were analysed for aberrations in the TP53 gene by immunohistochemistry (IHC), loss of heterozygosity (LOH) or mutation analysis. The MDM2 gene and its product was studied by Southern blotting and IHC. Over 50% of the OCs studied showed mutations in TP53 by either direct sequencing (19/36, 53%), positive IHC (23,43, 53%) or both, whereas 0/32 had amplification of MDM2 and only 1/37 tumours had positive IHC using the anti-MDM2 antibody IF-2. The solitary example of positive IHC in this series was seen in a mixed müllerian tumour with sarcomatous differentiation and was not accompanied by MDM2 DNA amplification. These results support previous data showing that around 50% of OCs have mutations in TP53 and in addition, suggest that MDM2 is not amplified in OC, but the presence of sarcomatous features in mixed müllerian tumours may result in positive immunohistochemistry with IF-2.

Chromosome Deletion↗

PubMed1995

The detection and localization of monocyte chemoattractant protein-1 (MCP-1) in human ovarian cancer.

Chemokines may control the macrophage infiltrate found in many solid tumors. In human ovarian cancer, in situ hybridization detected mRNA for the macrophage chemokine monocyte chemoattractant protein-1 (MCP-1) in 16/17 serous carcinomas, 4/4 mucinous carcinomas, 2/2 endometrioid carcinomas, and 1/3 borderline tumors. In serous tumors, mRNA expression mainly localized to the epithelial areas, as did immunoreactive MCP-1 protein. In the other tumors, both stromal and epithelial expression were seen. All tumors contained variable numbers of cells positive for the macrophage marker CD68. MCP-1 mRNA was also detected in the stroma of 5/5 normal ovaries. RT-PCR demonstrated mRNA for MCP-1 in 7/7 serous carcinomas and 6/6 ovarian cancer cell lines. MCP-1 protein was detected by ELISA in ascites from patients with ovarian cancer (mean 4.28 ng/ml) and was produced primarily by the cancer cells. Human MCP-1 protein was also detected in culture supernatants from cell lines and in ascites from human ovarian tumor xenografts which induce a peritoneal monocytosis in nude mice. We conclude that the macrophage chemoattractant MCP-1 is produced by epithelial ovarian cancer and that the tumor cells themselves are probably a major source. MCP-1 may contribute to the accumulation of tumor-associated macrophages, which may subsequently influence tumor behavior.

Adenocarcinoma↗

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

Expression and activity of MMPS and their regulators in ovarian cancer.

In order to understand the ability of human ovarian cancers to degrade the basement membrane, we have studied the localization and activity of matrix metalloproteases (MMPs) 2 and 9, using in situ hybridization and quantificative zymography on sequential sections of tumor biopsies. We have related these data to expression of some of the controlling elements of the enzymes, namely tissue inhibitors of metastasis (TIMPs) and tumor necrosis factor (TNF). mRNA for MMP-2 was found in the majority of cases and localized to stromal areas with maximal expression adjacent to neoplastic areas. MMP-9 expression was associated with cells in epithelial and stromal areas, consistent with distribution of macrophages. Zymography revealed higher levels of MMP-9 activity in the ovarian cancer biopsy samples than in other cancers studied, but in contrast to our previous observations in breast and bladder cancer, there was no correlation between MMP levels and tumor grade. Nor was there any association between amount of TNF mRNA and levels of MMP enzymes. TIMP-I expression was localized to stromal areas adjacent to tumor epithelial cells as well as, in some cases, to epithelial cells. The pattern of TIMP-2 expression was similar to that of MMP-2. We conclude that the stromal elements of ovarian tumors express MMP-2 and 9 and their specific inhibitors, but these do not seem to be controlled by endogenous TNF in the tumor microenvironment.

Biopsy↗