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Biomedical subjects

J A Royds

Publications and source records attributed to J A Royds.

At least 19 recordsLinked to original sources
PubMed2000

Macrophage infiltration is associated with VEGF and EGFR expression in breast cancer.

Angiogenesis is esential for tumour growth and metastasis. Vascular endothelial growth factor (VEGF) is a potent endothelial cell mitogen and is an important component of the angiogenic stimulus in a range of human neoplasias. In addition to its mitogenic activities, VEGF has also been found to stimulate migration in macrophages via the flt-1 VEGF receptor. It has previously been shown that increased focal tumour macrophage infiltration is associated with increased angiogenesis and worsened relapse-free and overall survival in breast cancer. Macrophages are able to stimulate angiogenesis by their production of a range of factors including VEGF, tumour necrosis factor-alpha (TNF-alpha), and thymidine phosphorylase (TP). Thus, in breast cancer, VEGF could have a dual role in the regulation of angiogenesis, by direct mitogenic stimulation of endothelial cells, and also indirectly by attracting macrophages into avascular tumours. The purpose of this study was to localize VEGF protein in a series of 96 consecutive primary breast carcinomas and to determine its relationship to focal macrophage infiltration (macrophage index). These two variables were also compared with the pathological features of the tumours, as well as oestrogen receptor (ER), epidermal growth factor receptor (EGFR), microvessel density, macrophage index, and survival. An inverse relationship (p=0.0006) was noted between VEGF and EGFR, with high VEGF expression correlating with low EGFR levels. In the EGFR-negative group of cases (n=56), positive associations were observed between VEGF expression and macrophage index (p=0.005), ER (p=0.05), p53 (p=0. 006), tumour grade (p=0.02), and tumour necrosis (p=0.03). Macrophage counts were higher in EGFR-positive tumours (p=0.0006) and no associations were found between VEGF expression and increased microvessel density. These results show that in breast cancers there are two types of macrophage infiltrates, one associated with the presence of EGFR and low VEGF expression in tumours and the other with high VEGF expression in EGFR-negative tumours. VEGF expression may be an important factor in the recruitment of tumour-associated macrophages into breast carcinomas and may thus have an additional, indirect, pathway of angiogenic stimulation in this type of tumour.

Adult↗
PubMed2000

Effect of mutation and conformation on the function of p53 in colorectal cancer.

In vitro studies have shown that immunoprecipitation with conformation-specific antibodies allows discrimination between different forms of p53; however, the significance of this has not been determined for human tumours. This study therefore examined p53 conformation in colorectal tumours and correlated this with mutational status and evidence of in vivo p53 downstream activity. Moreover, it was shown that for in vitro cell lines, DNA-damaging agents induce wild-type p53 to form a mutant conformation (PAb240+), with a concomitant rise in p21(WAF-1) expression. Induction of p53-mediated apoptosis, on the other hand, is associated with a wild-type conformation (PAb1620+). These results were confirmed for wild-type p53 in colorectal tumours. A range of p53 point mutations were found in exons 5-8 in colorectal tumours. Mutants with a wild-type conformation gave weak immunohistochemical staining, whereas mutations with flexible conformation (240+/1620+) gave intense positivity. Interestingly, this latter group of flexible mutants was also associated with features of poor prognosis. These studies show that not all p53 mutants are equal; thus, knowledge of the p53 status of a tumour may be required for a more precise prediction of prognosis and response to treatment for cancer patients.

Adult↗
PubMed1999

p53 expression, p21 expression and the apoptotic index in endometrioid endometrial adenocarcinoma.

AIMS: Although several genetic abnormalities are known to occur in endometrial cancer, including tp53 gene mutation, the pathogenesis of this common malignancy remains poorly defined. We investigated the relationship between overexpression of p53 protein, p21 protein expression and apoptosis in endometrial carcinoma. METHODS AND RESULTS: Sixteen cases of endometrial carcinoma in which polymerase chain reaction analysis had demonstrated the absence of a tp53 gene mutation were selected on the basis of p53 protein expression; p21 protein expression and the apoptotic index were then determined for each case. The proportion of cells in each case expressing p53 and p21 protein immunoreactivity was compared with the apoptotic index. Overall, no significant correlation was demonstrated between p53 and p21 immunoreactivity, or between either p53 or p21 and the apoptotic index. CONCLUSIONS: Factors other than p53 are involved in the regulation of p21 expression and apoptosis in endometrioid endometrial adenocarcinomas without p53 mutations. Despite the small numbers used in this study, the data suggest a correlation between low levels of p53 immunoreactivity and apoptosis. We postulate that high levels of p53 immunoreactivity may be due to abnormal stabilization of the p53 protein. Follow-up studies are needed with a larger data set.

Aged↗
PubMed1999

A simple method for PCR based analyses of immunohistochemically stained, microdissected, formalin fixed, paraffin wax embedded material.

Microdissection was performed on sections cut from formalin fixed, paraffin wax embedded archival material, which had been subjected to conventional immunohistochemistry. Crude DNA extracts, which were obtained from these microdissected samples by a simple microwave step, were then added directly to amplification reactions. Analyses using a range of polymerase chain reaction (PCR) based techniques, including microsatellite repeat polymorphism analysis at the NM23-H1 locus and sequencing of exons 5, 7, and 8 of the p53 gene, were performed successfully. Universal PCR amplification was also carried out on the microdissected material and probes suitable for use in comparative genomic hybridisation (CGH) were obtained in all cases. This technique will enable a range of effective genetic analyses to be carried out on specific subsets of cells that have been characterised previously by immunohistochemistry.

Colorectal Neoplasms↗
PubMed1999

IL-8 mRNA expression by in situ hybridisation in human pituitary adenomas.

Several cytokines have been shown to be expressed in normal and adenomatous pituitary tissue. Recently, interleukin-8 (IL-8) mRNA was identified by reverse transcription (RT)-PCR in each of a series of 17 pituitary tumours examined. We have investigated further the presence of IL-8 mRNA, using in situ hybridisation in two normal human anterior pituitary specimens and 25 human pituitary adenomas. IL-8 mRNA was not identified in either of the two normal pituitary specimens. Only three of the 25 adenomas were positive for IL-8 mRNA. In these three tumours, which included two null cell adenomas and one gonadotrophinoma, the majority of tumour cells (>90%) were positive for IL-8 mRNA. The remaining 22 adenomas were completely negative. There was no difference in tumour size or type between the IL-8 positive and the IL-8 negative tumours, and immunocytochemistry for von Willebrandt factor showed that the two groups were also similar in their degree of vascularisation. In conclusion, IL-8 mRNA was found in 12% of pituitary adenomas studied and was histologically identified within the tumour cells. In situ hybridisation is a more appropriate technique for assessing cytokine mRNA production by human pituitary tumours because RT-PCR may be too sensitive, identifying very small, possibly pathologically insignificant, quantities of mRNA that could be produced by supporting cells such as fibroblasts, endothelial cells or macrophages.

Adenoma↗
PubMed1998

Direct sequencing of the p53 gene shows absence of mutations in endometrioid endometrial adenocarcinomas expressing p53 protein.

AIMS: To investigate the mutational status of the p53 gene (Tp53) in endometrial carcinomas expressing p53 protein by direct gene sequencing. METHODS AND RESULTS: Eighteen cases of endometrial carcinoma, selected on the basis of p53 protein expression as detected immunohistochemically by the monoclonal antibody DO7, were microdissected in the p53 positive areas. DNA was extracted and subjected to polymerase chain reaction (PCR) for exons 5-8 which code for conserved areas containing mutational hot-spots. The PCR amplified material was then sequenced using an ABI automated sequencer and analysed using BLAST software at the NCBI web site. All sequences analysed were wild-type. CONCLUSION: The results confirm that expression of p53 protein may occur in endometrial adenocarcinoma without mutation and may be due to stabilization of the protein during its normal function, possibly by an mdm2 mediated process.

Adenocarcinoma↗
PubMed1998

Response of tumour cells to hypoxia: role of p53 and NFkB.

Hypoxia is present in several areas of malignant tumours and is thought to result from an inadequate rate of tumour angiogenesis, vascular collapse, or both. The presence and extent of these hypoxic tumour microenvironments have recently been shown to influence tumour progression by regulating both tumour cell survival and the expression of key angiogenic molecules. Recent studies have suggested that mutations in the tumour suppressor gene, p53, may play an important role in regulating the adaptive response of tumour cells to hypoxia by enhancing their survival and release of proangiogenic factors such as vascular endothelial growth factor. It has even been suggested that hypoxia may select for the survival of the more malignant clones harbouring such genetic defects as mutations in p53. Recently, the transcription factor, NFkB, has also been implicated as a novel mediator of the effects of hypoxia and reoxygenation in tumour cells. This article reviews some of the molecular mechanisms subserving the responses of tumour cells to hypoxic stress, particularly the role and relation of NFkB and p53 in regulating this phenomenon.

Genes, p53↗
PubMed1997

High level expression of p27(kip1) and cyclin D1 in some human breast cancer cells: inverse correlation between the expression of p27(kip1) and degree of malignancy in human breast and colorectal cancers.

The expression of cyclin-dependent kinase inhibitor p27(kip1) in human tumors and normal tissues was investigated using a panel of novel anti-p27(kip1) mAbs. An inverse correlation between expression of p27(kip1) and cell proliferation was generally observed after analyzing its expression in 25 different normal human tissues. In some highly proliferative human breast cancer cells, however, high level p27(kip1) expression was seen, indicating the existence of a mechanism by which some growing tumor cells may tolerate this inhibitor of cell cycle progression. Detailed studies demonstrated a correlation between the high level expression of p27(kip1) and cyclin D1 in human breast cancer cells. There was also an inverse correlation between the expression of p27(kip1) and the degree of tumor malignancy in human breast and colorectal cancers, indicating that p27(kip1) may be a useful prognostic marker in these cancers.

Biomarkers, Tumor↗
PubMed1997

Effect of interleukin-1 and dexamethasone on interleukin-6 production and growth in human meningiomas.

Interleukin-6 (IL-6) has been shown to be released by cultured human meningioma cells and may be a positive or negative regulator of tumour growth. IL-6 protein and mRNA levels have been examined in a series of meningiomas. In 14 cases, the results are compared with the effects of IL-6 and dexamethasone on growth and IL-6 secretion in vitro. Tumours with the highest in vivo IL-6 mRNA expression also showed maximum induction of IL-6 and increased cellular proliferation on IL-1 stimulation in vitro. Dexamethasone decreased the IL-1-stimulated IL-6 release in all cases. Meningiomas which had little or no IL-6 message were refractory to IL-1 control of IL-6. Remarkably, these formed the group of meningiomas that increased their growth rate in response to dexamethasone.

Adult↗
PubMed1997

The association between nm23 gene expression and survival in patients with sarcomas.

The relationship between the expression of nm23, a putative metastasis-suppressor gene and prognosis was determined for 88 patients with sarcomas. Immunohistochemistry using immunopurified anti-nm23 peptide antibodies was performed and the results of each case graded according to the degree of staining. Univariate and multivariate analyses were carried out to determine the prognostic significance of nm23 staining for sarcoma patients. Expression of nm23 was found to increase in line with metastatic potential in many cases but this did not reach significance for the study as a whole. However, the possibility of nm23 loss occurring in association with metastasis cannot be ruled out in some more aggressive sarcomas, as was demonstrated for six patients with low-scoring, unclassified and synovial sarcomas that had metastasized. The time to metastasis was longer for patients with grade 3 sarcomas (50-75% of tumour cells staining) than similar patients in other staining groups. These results suggest that expression of nm23 genes in sarcomas is variable and has no value as a prognostic indicator for these mesenchymal tumours.

Adolescent↗
PubMed1996

The nature of the cardiac myxoma.

Ten archive cases of cardiac myxoma were evaluated for proliferative activity, metastatic potential and expression of oncogene/tumor suppressor gene products by means of PCNA, MIB1, nm23, p53, Bcl-2 and Rb-1 immunohistochemistry. The myxomas showed variable proliferative activity (PCNA 0-41%, average 12.6%, MIB1 0-13%, average 3.2%) contrasting with the absence of mitotic activity histologically. All the myxomas showed nm23 staining. None showed p53 reactivity. Eight cases were negative for Bcl-2 expression, with two cases giving weak cytoplasmic staining. Rb-1 reactivity showed a variable pattern (staining indices 0-86%) paralleling the cases' proliferative activity. The cardiac myxoma is interpreted as a weakly proliferative lesion with little metastatic potential and no modulation of oncogene/oncogene suppressor products. Whilst not excluding a neoplastic aetiology, the results are considered more in keeping with a reactive/hamartomatous process.

Adult↗
PubMed1996

Absence of Epstein-Barr viral encoded RNA (EBER) in primary cutaneous t-cell lymphoma.

Epstein-Barr virus (EBV) has been associated with various extracutaneous lymphoproliferative diseases and it has been suggested that EBV may have a similar aetiological role in cutaneous T-cell lymphoma. In this study, in situ hybridization was used to investigate the presence of EBV encoded RNAs (EBER-1 and EBER-2) in 37 biopsies from 28 cases of primary cutaneous T-cell lymphoma originating from the U.K. The results showed that EBV had no demonstrable pathogenic role in the lymphomas studied, as EBER was not detected in any case.

Adult↗
PubMed1996

bcl-2 overexpression combined with p53 protein accumulation correlates with hormone-refractory prostate cancer.

Seventy-seven men with histologically proven and newly diagnosed prostate cancer we investigated for the presence of bcl-2 protein overexpression and p53 protein accumulation 1 immunohistochemistry. Forty-five men had evidence of locally advanced and metastatic disease and we treated by means of hormone manipulation. Twenty-eight patients either failed to respond to initial hormone manipulation or relapsed within 37 months from diagnosis (median 20 months). Of the 77 cancers, 37 (48% showed bcl-2 overexpression at diagnosis. Twenty-seven of those were treated with androgen ablation and 2 (74%) had hormone-refractory disease (P = 0.0128). Twenty-three of 77 men (29.8%) had nuclear staining for p53 protein. Twenty-one of those were treated with hormone manipulation and 14 (66.6%) showed hormone resistance (P = 0.0012). Seventeen patients had both bcl-2 overexpression and p53 protein accumulation, 16 of whom were hormonally treated, with 13 (81.2%) having hormone-refractory disease (P < 0.0001). These findings suggest that the combined detection of p53 protein accumulation and bcl-2 overexpression may be useful in predicting hormone resistance in prostate cancer. By deregulating programmed cell death, alteration in these genes may prevent patients from responding to androgen ablation, or allow them to escape hormonal control of the disease.

Adenocarcinoma↗
PubMed1994

Nm23 'anti-metastatic' gene product expression in colorectal carcinoma.

Nm23 is a putative metastasis suppressor gene and alterations in this gene have been reported in colorectal carcinomas suggestive of a role for nm23 in the dissemination of these tumours. In this study we used an affinity purified polyclonal antibody, ab-11, on formalin-fixed, paraffin-embedded sections of colorectal carcinomas from 46 patients in a three-stage avidin-biotin complex immunoperoxidase technique. Follow-up of these patients was until time of death or for 5 years, with a mean time of 31.2 months. Two observers scored the staining results from 1 to 3 according to the proportion of tumour cells positive. The association of nm23 staining with survival, sex, age, vascular invasion, and Dukes' stage was determined using Cox's regression model. The association of death from colorectal cancer and nm23 status reached marginal significance in this study (P = 0.0417). Moreover, there is some suggestion of a protective effect from nm23 as the relative risk of dying from colorectal cancer for each increment of nm23 positivity is 0.573 (95 per cent confidence limits 0.34-0.98).

Adenocarcinoma↗
PubMed1994

Diagnostic associations of p53 immunostaining in fine needle aspiration cytology of the breast.

Duplicate cytospin preparations were made from 46 symptomatic breast fine needle aspirates. One of each pair was assigned to benign or malignant categories by one experienced observer as part of the "triple approach" patient assessment. The other was immunostained with DO7, a monoclonal antibody to recombinant p53 protein, and rated by another observer as positive or negative for nuclear staining, unaware of the cytodiagnosis. Positive controls included carcinomas known to have mutant p53, while negative controls were of the reagent substitution type. Of the 26 aspirates with a benign cytodiagnosis (verified by the triple approach), 23 were p53 protein-negative and three positive. Of the 20 with a malignant cytodiagnosis (histologically confirmed), six were p53 protein-negative and 14 positive (exact P < 0.0001). As a diagnostic test this would give 70% sensitivity and 88% specificity.

Antibodies, Monoclonal↗
PubMed1994

Epstein-Barr virus in cutaneous lymphomatoid granulomatosis.

Epstein-Barr virus (EBV) has been associated with various extra-cutaneous lymphoproliferative diseases and it has been suggested that EBV may have a similar aetiological role in the skin. In this study, 10 biopsies from 7 cases of primary cutaneous lymphomatoid granulomatosis have been analyzed, using in situ hybridisation, for the presence of EBV encoded RNAs (EBER-1 and EBER-2). Only one case showed positive staining with the EBER probes and it is concluded that, in the skin, the relationship between EBV and lymphomatoid granulomatosis is variable. The role of EBV as an etiological agent in primary cutaneous lymphomatoid granulomatosis appears less important than in primary respiratory disease.

Adolescent↗
PubMed1994

Proliferating cell nuclear antigen immunostaining in keratoacanthoma and squamous cell carcinoma of the skin.

Proliferating cell nuclear antigen expression was used to seek differences between keratoacanthoma and squamous cell carcinoma of the skin. These lesions of the skin continue to provoke interest due to their different biological behaviour in spite of histologically similar appearances. The primary antibody, PC10 was used in a three stage avidin biotin peroxidase complex technique on section from 27 cases of KA, 15 of well, 16 of moderately- and 15 of poorly differentiated SCC. The distribution of positive cells was determined and then one thousand randomly chosen lesional epithelial nuclei were categorised for PCNA immunoreactivity and the results expressed as percentage of epithelial nuclei stained. Statistical analysis revealed a highly significant trend in increasing %PCNA with histological grade of skin lesion (P < 0.0001). Poorly differentiated, although not other grades of squamous cell carcinoma have a significantly higher proportion of PCNA labelled nuclei than keratoacanthoma. In addition, the distribution of PCNA positive nuclei in keratoacanthoma are usually peripheral contrasting with the more diffuse pattern seen in most cases of SCC. %PCNA alone was a more powerful predictor of histological subtype than distribution alone. PCNA immunohistochemistry not only provides additional information facilitating the differential diagnosis between keratoacanthoma and moderate or poorly differentiated squamous cell carcinoma but also underlines the perplexing similarity between keratoacanthoma and well differentiated squamous cell carcinoma.

Carcinoma, Squamous Cell↗