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Biomedical subjects

J Shipley

Publications and source records attributed to J Shipley.

At least 19 recordsLinked to original sources

Increased level of chromosomal damage after irradiation of lymphocytes from BRCA1 mutation carriers.

Deleterious mutations in the BRCA1 gene predispose women to an increased risk of breast and ovarian cancer. Many functional studies have suggested that BRCA1 has a role in DNA damage repair and failure in the DNA damage response pathway often leads to the accumulation of chromosomal aberrations. Here, we have compared normal lymphocytes with those heterozygous for a BRCA1 mutation. Short-term cultures were irradiated (8Gy) using a high dose rate and subsequently metaphases were analysed by 24-colour chromosome painting (M-FISH). We scored the chromosomal rearrangements in the metaphases from five BRCA1 mutation carriers and from five noncarrier control samples 6 days after irradiation. A significantly higher level of chromosomal damage was detected in the lymphocytes heterozygous for BRCA1 mutations compared with normal controls; the average number of aberrations per mitosis was 3.48 compared with 1.62 in controls (P=0.0001). This provides new evidence that heterozygous mutation carriers have a different response to DNA damage compared with noncarriers and that BRCA1 has a role in DNA damage surveillance. Our finding has implications for treatment and screening of BRCA1 mutation carriers using modalities that involve irradiation.

Chromosome Aberrations↗

Putting the colours into chromogenic in situ hybridization (CISH).

Recurrent genomic alterations are the hallmarks of particular cancers. Application of molecular cytogenetic technologies to tumour material in order to detect these alterations has become important for molecular diagnostics and research. A dual-colour chromogenic in situ hybridization (dc-CISH) method described recently in the Journal of Pathology has the advantage of visualizing two probes simultaneously with the ability to discern morphological features. In addition, the bright field microscopy required is readily accessible to many laboratories. The approach has been validated by comparison of results with standard analyses for HER-2 amplification status in formalin-fixed, paraffin-embedded breast cancers and is applicable to the analysis of other clinically relevant genomic aberrations as well as of use in research investigations.

Color↗

Gain of 1q25-32, 12q23-24.3, and 17q12-22 facilitates tumorigenesis and progression of human squamous cell lung cancer.

To explore the genetic changes involved in the stepwise development of lung cancer, we have determined the genetic events associated with the histological progression from normal bronchial epithelium to squamous cell carcinoma. Comparative genomic hybridization was used to identify chromosomal imbalances in 54 microdissected samples, including squamous metaplasia, dysplasia, carcinoma in situ, and invasive tumour derived from 23 patients with squamous cell carcinoma of the lung. Histopathological progression was accompanied by an increased number of chromosomal abnormalities. Gains of 1q25-32, 12q23-24.3, and 17q12-22, in particular, were detected at high frequencies in both carcinoma in situ and invasive tumours and were found more often in the cases with lymph node metastases than in those without. Our previous expression profiling of squamous cell carcinomas had identified overexpression of laminin5 gamma2, a gene located at 1q25-31. Therefore, this was investigated at the protein level by immunohistochemical analysis in 336 samples of squamous cell carcinoma of the lung. Consistent with the genomic data for this region, the expression level of laminin5 gamma2 was higher in the primary tumours with lymph node metastases than in tumours without metastases (p = 0.012). These data suggest that gains of genes from 1q25-32, 12q23-24.3, and 17q12-22 facilitate tumorigenesis and progression of squamous cell carcinoma of the lung, and may serve as potential predictors for this disease.

Aged↗

Molecular characterisation of the t(1;15)(p22;q22) translocation in the prostate cancer cell line LNCaP.

Although chromosome translocations are well-documented recurrent events in hematological malignancies and soft tissue sarcomas, their significance in carcinomas is less clear. We report here the molecular characterization of the reciprocal translocation t(1;15)(p22;q22) in the prostate carcinoma cell line, LNCaP. The chromosome 1 breakpoint was localized to a single BAC clone, RP11-290M5, by sequential FISH analysis of clones selected from the NCBI chromosome 1 map. This was further refined to a 580-bp region by Southern blot analysis. A 2.85-kb fragment spanning the der(1) breakpoint was amplified by long-range inverse PCR. The breakpoint on chromosome 1 was shown to lie between the CYR61 and the DDAH1 genes with the der(1) junctional sequence linking the CYR61 gene to the TSPAN3 (TM4SF8) gene on chromosome 15. Confirmatory PCR and FISH mapping of the der(15) showed loss of chromosome material proximal to the breakpoint on chromosome 15, containing the PSTPIP1 and RCN2 genes. On the available evidence we conclude that this translocation does not result in an in-frame gene fusion. Comparative expressed sequence hybridization (CESH) and comparative genomic hybridization (CGH) analysis, showed relative down-regulation of gene expression surrounding the breakpoint, but no gross change in genomic copy number. Real-time quantitative RT-PCR for genes around the breakpoint supported the CESH data. Therefore, here we may have revealed a gene down-regulation mechanism associated with a chromosome translocation, either through small deletion at the breakpoint or through another means of chromosome domain related gene regulation.

Base Sequence↗

Predictive power of an in vitro system to assess drug interactions of an antimuscarinic medication: a comparison of in vitro and in vivo drug-drug interaction studies of trospium chloride with digoxin.

The authors studied a potential drug-drug interaction via findings from in vitro and in vivo studies, to assess whether the in vitro system was predictive of in vivo clinical pharmacokinetic outcomes. An in vitro experiment and a clinical study were performed to assess the potential for interaction. The effect of trospium chloride on human P-glycoprotein-mediated transport of [3H]-digoxin was determined in vitro. A randomized, crossover clinical trial in 40 subjects was performed to evaluate the effect of trospium on the pharmacokinetics of digoxin in vivo. The findings from the studies were then compared. The in vitro findings in this study were corroborated by the clinical study via assessment of inhibition and impact on pharmacokinetic parameters. The in vitro system for assessment of a potential interaction of 2 drugs excreted primarily through the kidney was predictive of the pharmacokinetic outcomes obtained from a clinical setting.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Expression analysis onto microarrays of randomly selected cDNA clones highlights HOXB13 as a marker of human prostate cancer.

In a strategy aimed at identifying novel markers of human prostate cancer, we performed expression analysis using microarrays of clones randomly selected from a cDNA library prepared from the LNCaP prostate cancer cell line. Comparisons of expression profiles in primary human prostate cancer, adjacent normal prostate tissue, and a selection of other (nonprostate) normal human tissues, led to the identification of a set of clones that were judged as the best candidate markers of normal and/or malignant prostate tissue. DNA sequencing of the selected clones revealed that they included 10 genes that had previously been established as prostate markers: NKX3.1, KLK2, KLK3 (PSA), FOLH1 (PSMA), STEAP2, PSGR, PRAC, RDH11, Prostein and FASN. Following analysis of the expression patterns of all selected and sequenced genes through interrogation of SAGE databases, a further three genes from our clone set, HOXB13, SPON2 and NCAM2, emerged as additional candidate markers of human prostate cancer. Quantitative RT-PCR demonstrated the specificity of expression of HOXB13 in prostate tissue and revealed its ubiquitous expression in a series of 37 primary prostate cancers and 20 normal prostates. These results demonstrate the utility of this expression-microarray approach in hunting for new markers of individual human cancer types.

Biomarkers, Tumor↗

Dramatic response of malignant craniopharyngioma to cis-platin-based chemotherapy. Should craniopharyngioma be considered as a suprasellar 'germ cell' tumour?

The case is described of a 21-year-old woman, who developed a malignant tumour arising from a craniopharyngioma 14 years after the original diagnosis. The remarkable response of this malignant tumour ex-craniopharyngioma to cis-platin based chemotherapy, together with other midline tumour characteristics of craniopharyngioma, raise the question as to whether craniopharyngioma should any longer be separately considered from suprasellar germ cell tumour. This subject is discussed.

Adolescent↗

PAX7 expression in embryonal rhabdomyosarcoma suggests an origin in muscle satellite cells.

Rhabdomyosarcoma (RMS) is a common paediatric soft tissue sarcoma that resembles developing foetal skeletal muscle. Tumours of the alveolar subtype frequently harbour one of two characteristic translocations that juxtapose PAX3 or PAX7, and the forkhead-related gene FKHR (FOXO1A). The embryonal subtype of RMS is not generally associated with these fusion genes. Here, we have quantified the relative levels of chimaeric and wild-type PAX transcripts in various subtypes of RMS (n=34) in order to assess the relevance of wild-type PAX3 and PAX7 gene expression in these tumours. We found that upregulation of wild-type PAX3 is independent of the presence of either fusion gene and is unlikely to contribute to tumorigenesis. Most strikingly, upregulated PAX7 expression is almost entirely restricted to cases without PAX3-FKHR or PAX7-FKHR fusion genes and may contribute to tumorigenesis in the absence of chimaeric PAX transcription factors. Furthermore, as myogenic satellite cells are known to express PAX7, this pattern of PAX7 expression suggests this cell type as the origin of these tumours. This is corroborated by the detection of MET (c-met) expression, a marker for the myogenic satellite cell lineage, in all RMS samples expressing wild-type PAX7.

Animals↗

Distinct genetic and epigenetic changes in medullary breast cancer.

Genetic instability resulting in chromosome aneuploidy or mismatch repair deficiency characterizes cancer. Medullary carcinoma (MC) of the breast is a specific form of breast cancer with unique clinical, epidemiologic, and prognostic features, suggesting distinctive tumorigenic pathways. To investigate the nature of the genetic changes associated with MC we analyzed a series of 22 tumors. Chromosomal imbalances were assessed by comparative genomic hybridization (CGH) and mismatch repair (MMR) deficiency tested for through assessment of microsatellite instability (MSI) and expression of MLH1 and MSH2 genes. MMR deficiency was detected in only a small proportion of cases. The chromosomal copy number changes showed some similarities to BRCA1-associated tumors. A high level of BRCA1 promoter hypermethylation was detected, suggesting a possible role of this gene in MC development.

Adaptor Proteins, Signal Transducing↗

Low frequency of somatic mutations in the FH/multiple cutaneous leiomyomatosis gene in sporadic leiomyosarcomas and uterine leiomyomas.

Germline mutations in the fumarate hydratase gene at 1q43 predispose to dominantly inherited skin and uterine leiomyomata and leiomyosarcomas. The enzyme, which is a component of the tricarboxylic acid cycle, acts as a tumour suppressor. To evaluate fumarate hydratase in respective sporadic tumours, we analysed a series of 26 leiomyosarcomas and 129 uterine leiomyomas (from 21 patients) for somatic mutations in fumarate hydratase and allelic imbalance around 1q43. None of the 26 leiomyosarcomas harboured somatic mutations in fumarate hydratase. Fifty per cent of leiomysarcomas tested showed evidence of allelic imbalance at 1q, but this was not confined to the vicinity of fumarate hydratase. Only 5% (seven out of 129) of the leiomyomas showed allele imbalance at 1q42-q43 and no somatic mutations in fumarate hydratase were observed. Our findings indicate that mutations in fumarate hydratase do not play a major role in the development of sporadic leiomyosarcomas or uterine leiomyomas

Adult↗

Chromosomal imbalances in familial chronic lymphocytic leukaemia: a comparative genomic hybridisation analysis.

A subset of B cell chronic lymphocytic leukaemia (CLL) is familial. Lack of large families makes it attractive to exploit methods in addition to genetic linkage analysis for the identification of a susceptibility locus. One strategy that can localise regions of the genome that may harbour tumour suppressor genes is to identify regions of chromosomal imbalance using comparative genomic hybridisation (CGH) analysis. We examined 24 familial CLL cases by CGH analysis. Losses that are documented as arising frequently in sporadic CLL were observed at a comparable frequency in familial CLL. However, gains and losses in two regions of the X chromosome - Xp11.2-p21 and Xq21-qter - appear more common in familial CLL than in sporadic CLL. This suggests these regions may harbour a susceptibility locus for CLL. There is also some evidence that chromosome regions 2p12-p14 and 4q11-q21 may harbour predisposition genes.

Chromosome Aberrations↗

Detection of the PAX3-FKHR fusion gene in paediatric rhabdomyosarcoma: a reproducible predictor of outcome?

Rhabdomyosarcoma has 2 major histological subtypes, embryonal and alveolar. Alveolar histology is associated with the fusion genes PAX3-FKHR and PAX7-FKHR. Definition of alveolar has been complicated by changes in terminology and subjectivity. It is currently unclear whether adverse clinical behaviour is better predicted by the presence of these fusion genes or by alveolar histology. We have determined the presence of the PAX3/7-FKHR fusion genes in 91 primary rhabdomyosarcoma tumours using a combination of classical cytogenetics, FISH and RT-PCR, with a view to determining the clinical characteristics of tumours with and without the characteristic translocations. There were 37 patients with t(2;13)/PAX3-FKHR, 8 with t(1;13) PAX7-FKHR and 46 with neither translocation. One or other of the characteristic translocations was found in 31/38 (82%) of alveolar cases. Univariate survival analysis revealed the presence of the translocation t(2;13)/PAX3-FKHR to be an adverse prognostic factor. With the difficulties in morphological diagnosis of alveolar rhabdomyosarcoma on increasingly used small needle biopsy specimens, these data suggest that molecular analysis for PAX3-FKHR will be a clinically useful tool in treatment stratification in the future. This hypothesis requires testing in a prospective study. Variant t(1;13)/PAX7-FKHR appears biologically different, occurring in younger patients with more localised disease.

Adolescent↗

Comparative expressed sequence hybridization to chromosomes for tumor classification and identification of genomic regions of differential gene expression.

Altered expression of genes can have phenotypic consequences in cancer development and treatment, developmental abnormalities, and differentiation processes. Here we describe a rapid approach, termed comparative expressed sequence hybridization (CESH), which gives a genome-wide view of relative expression patterns within tissues according to chromosomal location. No prior knowledge of genes or cloning is required, and minimal amounts of tissue can be used. Expression profiles are achieved in a manner similar to the identification of chromosomal imbalances by comparative genomic hybridization analysis. The approach is demonstrated to indicate a chromosomal region that harbors overexpressed genes that may be associated with a drug-resistant phenotype. In addition, known and new regions of differential gene expression in both normal tissues and tumor samples from the soft tissue sarcoma group of rhabdomyosarcoma (RMS) are indicated. These regions included 2p24; overexpression of MYCN at 2p24 was confirmed by quantitative reverse transcription-PCR for all of the alveolar RMS cases and did not necessarily correspond to genomic amplification. Evidence including region specific microarray analysis indicated that overexpression of several genes from a region may be required for detection by CESH. This evidence is consistent with clusters of functionally related genes and mechanisms that affect the expression of a number of genes at a particular genomic location. The distinctive CESH profiles demonstrated in different subtypes of RMS show potential for tumor classification.

Chromosomes, Artificial, Yeast↗

Chromosomal imbalances associated with carcinoma in situ and associated testicular germ cell tumours of adolescents and adults.

Carcinoma in situ (CIS) or intratubular germ cell neoplasia is generally considered the precursor lesion of adult testicular germ cell tumours (TGCT). The chromosomal imbalances associated with CIS and the corresponding seminoma (SE) or nonseminoma (NS) have been determined by comparative genomic hybridization (CGH) analysis of microdissected material from seven cases. Significantly, the CIS showed no gain of 12p material whereas in the invasive components of all cases gain of 12p was found, in 2 cases associated with amplification of the 12p11.2-12.1 region. Interphase fluorescence in situ analysis was consistent with this and provided evidence for the i(12p) or 12p11.2-12.1 amplification in the SE and NS but not in the corresponding CIS. This suggests a role for these changes in progression of CIS to invasive testicular cancer or progression of the invasive disease. Other imbalances such as gain of material from chromosomes 1, 5, 7, 8, 12q and X and loss of material from chromosome 18 were frequently identified (> 40% of cases) in the CIS associated with both SE and NS as well as in the invasive components. Loss of material from chromosome 4 and 13 and gain of 2p were more frequently found in the invasive components. The results shed light on the genetic relationship between the non-invasive and invasive components of testicular cancer and the stage at which particular chromosomal changes may be important.

Adolescent↗

Definition of chromosome aberrations in testicular germ cell tumor cell lines by 24-color karyotyping and complementary molecular cytogenetic analyses.

Many of the reported karyotypes for adult testicular germ cell tumors (GCTs) are complex and incomplete, although the presence of an isochromosome 12p, i(12p), and gain of 12p material have consistently been found. Here, an accurate definition of the chromosome aberrations associated with four cell lines derived from GCTs (GCT27, H12.1, Tera1, and Tera2) has been produced using 24-color karyotyping by mulifluor in situ hybridization, comparative genomic hybridization analysis, and further fluorescence in situ hybridization analysis to confirm some chromosomal assignments and refine involvement of specific regions of 12p. There was karyotypic heterogeneity. Isochromosomes in addition to i(12p) were found, as were other rearrangements with breakpoints at or near centromeric regions. The most frequent non-centromeric breakpoints were at 1p31 approximately p32, 1p21 approximately p22, 11q13, and Xq22, although consistent partner chromosomes were not involved. One cell line (Tera1) showed a subtle dosage increase in the copy number of a 12p probe known to be within the smallest overlapping region of amplification that has been defined in a number of testicular GCTs with amplicons at 12p11 approximately p12. The chromosome rearrangements and associated imbalances may be significant in GCT progression and the characterized cell lines can be used to investigate these further.

Chromosome Aberrations↗

Disruption of the ATM gene in breast cancer.

Mutations in the ATM gene, which maps to 11q22-23, cause the multisystem recessive syndrome ataxia-telangiectasia (AT). Breast cancer has been reported in AT patients and carriers. Sporadic breast cancer is associated with loss of heterozygosity at or in the region of ATM and chromosomal abnormalities involving 11q23. We have investigated the chromosomes, nuclei and released chromatin fibers from nine primary breast carcinoma and eight cell lines by fluorescence in situ hybridization with four fluorochrome-labeled cosmids spanning the ATM gene. The ATM gene was disrupted in one primary breast carcinoma and in the cell lines MDA-MB-231 and MCF-7. The role of these aberrations in breast carcinomas, which may lead to gene dosage or dominant negative effects on gene function, requires further investigation.

Ataxia Telangiectasia Mutated Proteins↗

Cytogenetic abnormalities in 42 rhabdomyosarcoma: a United Kingdom Cancer Cytogenetics Group Study.

BACKGROUND: Rhabdomyosarcomas are the most common type of pediatric soft tissue sarcoma. The cytogenetic literature on RMS is biased towards the less common alveolar subtype (ARMS), which is frequently associated with specific translocations and the PAX3/7-FKHR fusion genes. Relatively few karyotypes are reported for the embryonal subtype (ERMS). The aim of this study was to further cytogenetic knowledge of RMS subtypes. PROCEDURE: Representative examples of all karyotypes from UKCCG; member laboratories were reexamined and their histopathologies reviewed through the United Kingdom Children's Cancer Study (Group) (UKCCSG). Molecular evidence for the PAX3/7-FKHR fusion genes was available for five ERMS and seven ARMS cases and compiled with the karyotypes. RESULTS: Clonal chro mosome aberrations were characterized for 25 ERMS and 17 ARMS cases. Thirty-six percent of the ERMS cases involved translocation breakpoints in the 1p11-q11 region. Ten of the seventeen cases of ARMS showed cytogenetic evidence for the t(2;13)(q35;q14), consistent with molecular data available from four of these. Two further ARMS cases revealed a PAX3-FKHR and a variant PAX7-FKHR fusion gene product that were not detected cytogenetically. CONCLUSIONS: Many of the karyotypes from both subtypes were complex. The frequent involvement of the 1p11-1q11 region and gain of chromosomes 2, 8, 12, and 13 in ERMS may be functionally significant. There was no evidence for involvement of the PAX3/7-FKHR genes in ERMS, and cryptic involvement was found in some ARMS. There were no consistent chromosomal rearrangements associated with apparently translocation negative ARMS cases.

Adolescent↗

Characterization of chromosome aberrations associated with soft-tissue leiomyosarcomas by twenty-four-color karyotyping and comparative genomic hybridization analysis.

Data on the chromosome aberrations associated with leiomyosarcomas of soft tissues are limited, complex, and incomplete. The aim of this study was to characterize genetic aberrations associated with this tumor group, to identify consistent regions of involvement and to determine correlations with clinical outcome. Chromosomes were prepared from 10 primary soft-tissue leiomyosarcoma samples, and preparations from four of them, plus the cell line SK-LMS-1, were suitable for analysis using 24-color karyotyping by multifluor fluorescence in situ hybridization. This method allowed rearranged chromosomes to be characterized, which would not have been possible by banding analysis alone. The remaining six chromosome preparations were analyzed using standard Giemsa banding. The chromosome imbalances associated with all the samples were determined by comparative genomic hybridization analysis. Taken together, the results show both intra- and intertumor heterogeneity and considerable complexity. Although no highly consistent rearrangements were found, some regions of the genome frequently were involved, including 1q21, 5p14-pter, and 20q13, which likely harbor genes that play a role in the pathogenesis of soft-tissue leiomyosarcomas. There were no obvious correlations between the chromosomal changes identified and available clinical details.

Adult↗