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Biomedical subjects

P Englefield

Publications and source records attributed to P Englefield.

9 recordsLinked to original sources
PubMed1998

BRCA1 mutations in southern England.

If genetic testing for breast and ovarian cancer predisposition is to become available within a public health care system there needs to be a rational and cost-effective approach to mutation analysis. We have screened for BRCA1 mutations in 230 women with breast cancer, all from the Wessex region of southern England, in order to establish the parameters on which to base a cost-effective regional mutation analysis strategy. Truncating mutations were detected in 10/155 (6.5%) consecutive cases selected only for diagnosis under the age of 40 (nine of these ten women had a strong family history of breast or ovarian cancer), 3/61 (4.9%) bilateral-breast cancer cases (all three mutations occurring among women for whom the first cancer was diagnosed under 40 years) and 8/30 (26.6%) breast cancer cases presenting to the genetics clinic (for whom a strong family history of breast and/or ovarian cancer was present). Ten different mutations were detected in 17 families, but three of these accounted for 10/17 (59%) of the families. The cost of screening the population for mutations in the entire BRCA1 gene is unacceptably high. However, the cost of screening a carefully selected patient cohort is low, the risk of misinterpretation much less and the potential clinical benefits clearer.

Adult↗
PubMed1996

Microsatellite analysis of endometriosis reveals loss of heterozygosity at candidate ovarian tumor suppressor gene loci.

Endometriosis is a very common gynecological condition in which tissue similar to endometrium proliferates at sites outside the uterine cavity, most commonly the ovary. Although it generally remains a benign condition, malignant transformation has been documented. and it is commonly found in association with endometrioid subtype ovarian cancer. Tumor suppressor genes are commonly altered in ovarian cancers, and the development of endometriosis may involve mutations in the same class of genes. We have investigated this possibility by examining DNA from 40 cases of endometriosis for clonal status, alterations in TP53 and RASK, and allelic losses at candidate ovarian tumor suppressor loci on chromosome arms 6q, 9p, l1q, 17p, l7q, and 22q. The majority of endometriotic cysts were monoclonal, but interestingly, 8 of 10 normal endometrial glands were also monoclonal, demonstrating that both are able to develop from a single progenitor cell. No mutations were detected in TP53 or RASK. Loss of heterozygosity (LOH) was detected on chromosomes 9p (18%), 1lq (18%), and 22q (15%). In total, 11 of 40 (28%) cases demonstrated LOH at one or more of these loci. This study, which is the first to report LOH in endometriosis, supports the notion that tumor suppressor gene inactivation may play a role in the development of at least a subset of cases.

Base Sequence↗
PubMed1995

LOH and mutation analysis of CDKN2 in primary human ovarian cancers.

The CDKN2 gene encodes a cell cycle regulatory protein and is located on chromosome 9p21, a region deleted in a wide variety of primary tumours. While mutations in the CDKN2 gene itself are frequently observed in tumour cell lines, they are less common in primary tumours. We have investigated the role of the CDKN2 gene in ovarian cancer by analysis for allelic loss of 9p21 and single-strand conformational polymorphism analysis of exons 1 and 2 of CDKN2 in 67 primary ovarian tumours. Loss of heterozygosity on 9p21 was frequently observed (24/50 informative tumours) and was common in early-stage tumours, suggesting that it is an early event in ovarian tumorigenesis. Homozygous deletion of the CDKN2 gene was detected in only 1 tumour. No somatic or germline mutations were observed in CDKN2, though a codon 140 polymorphism was detected in 2 cases. This suggests that CDKN2 is not involved in ovarian tumorigenesis and that another gene(s) may be the target of the frequent 9p allelic losses observed.

Base Sequence↗
PubMed1994

Mutation analysis of RASK and the 'FLR exon' of NF1 in sporadic ovarian carcinoma.

Frequent loss of heterozygosity has been described on several chromosomes in ovarian carcinoma (OC), but few tumour suppressor genes (TSGs) have been analysed. Mutations in the GTPase-related domain (GRD) of the TSG NF1 have been described in tumours not usually associated with neurofibromatosis type 1 (NF1). We analysed 36 OCs for mutations in this domain using single-strand conformation polymorphism. The NF1-GRD can downregulate the active form of p21RAS and, therefore, we analysed the same tumours for mutations in RASK. No cases of mutations in NF1-GRD were seen, and only two cases of RASK mutations were found. Thus, activation of the RAS signalling pathway by RASK or NF1 mutations does not appear to be common in OC.

Adenocarcinoma, Mucinous↗
PubMed1994

Loss of heterozygosity on chromosome 22 in ovarian carcinoma is distal to and is not accompanied by mutations in NF2 at 22q12.

Frequent loss of heterozygosity (LOH) has been reported on 22q in ovarian carcinoma, implying the presence of a tumour-suppressor gene. The neurofibromatosis type 2 gene (NF2) at 22q12 is a plausible candidate. Analysis of 9 of the 17 exons of NF2 by single-strand conformational polymorphism (SSCP) in 67 ovarian carcinomas did not detect any somatic mutations, suggesting that NF2 is not involved in the pathogenesis of ovarian carcinoma. LOH data support this conclusion and that the putative tumour-suppressor gene lies distal to NF2, beyond D22S283.

Alleles↗
PubMed1994

Expression of integrin adhesion molecules in endometrium and endometriosis.

OBJECTIVE: To compare the expression of cell adhesion molecules by endometrium and endometriosis. DESIGN: A comparative study of integrin expression, determined immunohistochemically, in eutopic and ectopic endometrium biopsied synchronously from patients with endometriosis diagnosed at laparoscopy or laparotomy. SETTING: University Departments of Obstetrics and Gynaecology, and Pathology, Southampton; Department of Obstetrics and Gynaecology, Newcastle upon Tyne. SAMPLES: Eighteen paired samples of endometria and endometriosis. RESULTS: A wide distribution of collagen-laminin receptor proteins was demonstrated. alpha 1 integrin expression was limited to secretory endometrium. beta 3 expression was only demonstrated on proliferative endometrium. CONCLUSIONS: Expressions of the integrin proteins differed between the various elements of the endometrium. Cyclical changes in integrin expression also were demonstrated. No difference in cell adhesion molecule expression was seen when comparing endometrial and endometriosis samples.

Cell Adhesion Molecules↗
PubMed1989

An enzyme-linked immunosorbent assay (ELISA) for the measurement of serum antibodies to growth hormone. The Wessex Growth Study.

A solid-phase enzyme-linked immunosorbent assay for measuring antibodies to growth hormone (GH) was developed, with occasional use and long shelf-life in mind. With coating protein concentration optimised, the standard curve was linear over a 25-fold range of concentration. The interassay coefficient of variation ranged from 14.4% to 9.3%. The specificity of the assay was confirmed by the substitution of insulin for GH as coating protein and by preabsorption of sera with GH coupled covalently to Sepharose beads. There was no binding signal with insulin and absorption was dose dependent, maximum (greater than 80% complete) with 2 x 10(4) micrograms GH/ml undiluted serum. The assay was simple to perform, cheap and reliable.

Antibodies↗