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Biomedical subjects

P G Murray

Publications and source records attributed to P G Murray.

At least 19 recordsLinked to original sources
PubMed2007

Hypoxia-regulated carbonic anhydrase IX expression is associated with poor survival in patients with invasive breast cancer.

Tumour hypoxia is a microenvironmental factor related to poor response to radiation, chemotherapy, genetic instability, selection for resistance to apoptosis, and increased risk of invasion and metastasis. Hypoxia-regulated carbonic anhydrase IX (CA IX) has been studied in various tumour sites and its expression has been correlated with the clinical outcome. The purpose of this study was to investigate the correlation of CA IX expression with outcome in patients with invasive breast cancer. We conducted a retrospective study examining the effects of carbonic anhydrase IX (CA IX) on survival in patients with breast cancer. To facilitate the screening of multiple tissue blocks from each patient, tissue microarrays were prepared containing between two and five representative samples of tumour per patient. Immunohistochemistry was used to examine expression of CA IX in patients with breast cancer. The study includes a cohort of 144 unselected patients with early invasive breast cancer who underwent surgery, and had CA IX expression and follow-up data available for analysis. At the time of analysis, there were 28 deaths and median follow-up of 48 months with 96% of patients having at least 2 years of follow-up. CA IX was negative for 107 patients (17 deaths) and positive for 37 patients (11 deaths). Kaplan-Meier survival curves show that survival was superior in the CA IX-negative group with a 2-year survival of 97% for negatives and 83% for positives (log-rank test P=0.01). Allowing for potential prognostic variables in a Cox regression analysis, CA IX remained a significant independent predictor of survival (P=0.035). This study showed in both univariate and multivariate analysis that survival is significantly inferior in patients with tumour expressing CA IX. Prospective studies are underway to investigate this correlation in clinical trial setting.

Adult↗
PubMed2006

Epstein-Barr virus in breast cancer: artefact or aetiological agent?

The Epstein-Barr virus (EBV) has been reported to be associated with a variety of different tumours; for some of these malignancies, including breast cancer, the association remains controversial. This might be due in part to differences in the methodologies used to detect EBV in tissue samples. One approach favoured by many groups is to use immunohistochemistry to detect an EBV protein, EBNA1, which is essential for the maintenance of viral latency in infected cells and therefore should be a good marker for the presence of the virus. However, in this issue of the Journal of Pathology, Hennard and colleagues report that one of the antibodies frequently employed to detect EBNA1 in tissue samples cross-reacts with the MAGE4 protein, a cancer testis antigen expressed in many cancer types. Their observation suggests that reports documenting an EBV association on the basis of reactivity with this antibody must be considered unreliable. It also re-opens the debate about whether breast cancer is an EBV-associated disease.

Antibodies, Viral↗
PubMed2004

A novel multiplex RT-PCR system detects human endogenous retrovirus-K in breast cancer.

Human endogenous retrovirus HERV-K like-sequences have been implicated in certain cancers. We developed a novel multiplex RT-PCR system for HERV-K that yielded a 533 bp product together with a smaller sized product (319 bp) of the house keeping gene, histidyl tRNA synthetase (HtRNAS). The latter spanned an intron that also served to validate target cDNA. PCR amplicons of HERV-K and HtRNAS were visualised using a gel documentation system and the pixel intensity used to derive semi-quantitative levels of viral expression. Our data showed that HERV-K10 was significantly elevated in MCF-7 cells treated with estrogen. Interestingly, HERV-K expression was higher in MCF-7 cells selected with adriamycin. RT-PCR combined with Southern blotting also detected HERV-K from breast cancer tissue using laser capture microscopy. This study highlights the presence of HERV-K in the breast cancer cell lines MCF-7 and MCF-7 ADR and confirms HERV-K10 transcripts in the cell line T47D. We believe this study to be a novel approach in determining levels of HERV-K expression and for detecting this virus in cancer cell lines and tissues.

Breast Neoplasms↗
PubMed2004

Expression of the cellular FLICE-inhibitory protein (c-FLIP) protects Hodgkin's lymphoma cells from autonomous Fas-mediated death.

Hodgkin's lymphoma (HL) is characterized by the presence of malignant so-called Hodgkin's/Reed-Sternberg (HRS) cells, which display resistance to certain apoptotic stimuli, including a lack of sensitivity to Fas-mediated cell death. However, the mechanisms responsible for their resistance to apoptosis inducers have not been elucidated. Here we confirm that both HL-derived cell lines and the HRS cells of primary HL tissues express Fas ligand (FasL) along with the inhibitory c-FLIP protein. Down-regulation of cellular FLICE (FADD-like IL-1beta-converting enzyme)-inhibitory protein (c-FLIP) through the use of specific small inhibitory RNAs (siRNAs) leads to reduced viability of the L428 and L591 HL-derived cell lines. To determine whether endogenous FasL was responsible for the reduction in cell viability observed after down-regulation of c-FLIP, L428 and L591 cells were treated with c-FLIP-specific siRNAs with and without siRNAs directed to FasL. Treatment of these cells with both c-FLIP- and FasL-specific siRNAs in combination restored cell viability to near control levels. Our results provide a mechanism whereby HRS cells are protected from autonomous FasL-mediated cell death while preserving their ability to evade immunosurveillance. Targeting c-FLIP could provide a novel approach to the treatment of HL.

Apoptosis↗
PubMed2004

Human endogenous retroviruses: transposable elements with potential?

Human endogenous retroviruses (HERVs) are a significant component of a wider family of retroelements that constitute part of the human genome. These viruses, perhaps representative of previous exogenous retroviral infection, have been integrated and passed through successive generations within the germ line. The retention of HERVs and isolated elements, such as long-terminal repeats, could have the potential to harm. In this review we describe HERVs within the context of the family of known transposable elements and survey these viruses in terms of superantigens and molecular mimics. It is entirely possible that these mechanisms provide the potential for undesired immune responses.

DNA Transposable Elements↗
PubMed2004

Demystified...recombinant antibodies.

Recombinant antibodies are important tools for biomedical research and are increasingly being used as clinical diagnostic/therapeutic reagents. In this article, a background to humanized antibodies is given, together with details of the generation of antibody fragments--for example, single chain Fv fragments. Phage antibody fragments are fast becoming popular and can be generated by simple established methods of affinity enrichment from libraries derived from immune cells. Phage display methodology can also be used for the affinity enrichment of existing antibody fragments to provide a reagent with a higher affinity. Here, phage antibodies are demystified to provide a greater understanding of the potential of these reagents and to engage clinicians and biomedical scientists alike to think about potential applications in pathology and clinical settings.

Animals↗
PubMed2003

Molecular characterisation and expression analysis of the first hemicellulase gene (bxl1) encoding beta-xylosidase from the thermophilic fungus Talaromyces emersonii.

The gene coding for beta-xylosidase, bxl1, has been cloned from the thermophilic filamentous fungus, Talaromyces emersonii. This is the first report of a hemicellulase gene from this novel source. At the genomic level, bxl1 consists of an open reading frame of 2388 nucleotides with no introns that encodes a putative protein of 796 amino acids. The bxl1 translation product contains a signal peptide of 21 amino acids that yields a mature protein of 775 amino acids, with a predicted molecular mass of 86.8 kDa. The deduced amino acid sequence of bxl1 exhibits considerable homology with the primary structures of the Aspergillus niger, Aspergillus nidulans, Aspergillus oryzae, and Trichoderma reesei beta-xylosidase gene products, and with some beta-glucosidases, all of which have been classified as Family 3 glycosyl hydrolases. Northern blot analysis of the bxl1 gene indicates that it is induced by xylan and methyl-beta-D-xylopyranoside. D-Xylose induced expression of bxl1 but was shown to repress induction of the gene at high concentrations. The presence of six CreA binding sites in the upstream regulatory sequence (URS) of the bxl1 gene indicates that the observed repression by D-glucose may be mediated, at least partly, by this catabolite repressor.

5' Untranslated Regions↗
PubMed2003

Proapoptotic genes BAX and CD40L are predictors of survival in transitional cell carcinoma of the bladder.

The purpose of the study was to investigate the effects of expression of a range of genes involved in apoptosis on outcome in bladder cancer. Immunohistochemistry was used to examine expression of BCL2, BAX, P53, CD40 and CD40L in archival tissues of patients included in various treatment trials for transitional cell carcinoma (TCC) of the bladder. Data were collected on 94 patients who first presented with either invasive or superficial bladder cancer. Median follow-up for alive patients was 83 months (m) (range 12-195 m). Median survival was 80 m (95% CI=56-128 m). Median survivals for the various markers were as follows: BAX-positive patients 110 m vs BAX-negative patients 18 m (P=0.0002); CD40L-positive patients 95 m vs CD40L-negative patients 45 m (P=0.04); BCL2-positive patients 44 m and BCL2-negative patients 74 m, (P=0.64); CD40-positive patients 110 m and CD40 negative patients 45 m (P=0.12); and P53 positive patients 80 m and P53 negative patients 45 m (P=0.58). In conclusion, it was seen that overexpressions of BAX and CD40L are prognostic of better survival in TCC of the bladder. Our results also raise the possibility of the future development of CD40- and CD40 ligand-based immunotherapy for bladder cancer. This study links proapoptotic and antiapoptotic markers to overall survival.

Adult↗
PubMed2003

Molecular cloning, transcriptional, and expression analysis of the first cellulase gene (cbh2), encoding cellobiohydrolase II, from the moderately thermophilic fungus Talaromyces emersonii and structure prediction of the gene product.

A gene (cbh2) encoding cellobiohydrolase II was isolated from the fungus Talaromyces emersonii by rapid amplification of cDNA ends techniques and the equivalent genomic sequence was subsequently cloned. This represents the first report of a key component of the cellulase regulon from this organism. DNA sequencing revealed that cbh2 has an open reading frame of 1377 bp, which encodes a putative polypeptide of 459 amino acids, and is interrupted by seven introns. The deduced amino acid sequence revealed that cbh2 has a modular structure with a predicted molecular mass of 47 kDa and consisting of a fungal type carbohydrate binding module separated from a catalytic domain by a proline/serine/threonine rich linker region. The deduced protein is homologous to fungal cellobiohydrolases in Family 6A of the glycosyl hydrolases. Profiles of cbh2 expression in T. emersonii investigated by Northern blot analysis revealed that expression is regulated at the transcriptional level. Expression of the T. emersonii cbh2 gene is induced by cellulose, xylan, xylose, and gentiobiose and clearly repressed by glucose. Putative regulatory element consensus sequences have been identified in the upstream regulatory sequence of the cbh2 gene including the catabolite repressor element and the activator of cellulase expression (Ace) binding sites. High sequence identity (67%) between the catalytic domain of Cel 6A from Trichoderma reesei and the T. emersonii cbh2 gene product allowed structure prediction for the 3D model of the T. emersonii catalytic domain to be a variant of the classical TIM alpha/beta fold.

Amino Acid Sequence↗
PubMed2003

The effect of Epstein-Barr virus status on outcome in age- and sex-defined subgroups of patients with advanced Hodgkin's disease.

BACKGROUND: Conflicting data on the effect of the Epstein-Barr virus (EBV) on outcome in Hodgkin's disease (HD) might be due to the heterogeneous nature of this disease. In this study we have investigated whether the effect of EBV status on outcome is different between aetiologically defined age groups (15-34, 35-44, 45+ years) and also between males and females. PATIENTS AND METHODS: Paraffin-embedded sections from 273 patients with advanced HD from two related clinical trials were analysed for the presence of EBV using in situ hybridisation. RESULTS: EBV was detected in 78 (29%) of cases. For all patients, after a median follow-up of 5 years, there were no significant differences in survival by EBV status although there was a trend towards longer failure-free survival times for EBV-positive patients. Multivariate analyses suggested that EBV and sex, when in combination, were prognostic factors for failure-free survival (P = 0.06 for both). For subgroups, the effect of EBV on failure-free survival was significant for males and 15-34 years age group (P = 0.05 and P = 0.03, respectively). CONCLUSION: This study suggests that with a median follow-up of 5 years, EBV status does not affect survival but being EBV-positive may be beneficial in terms of failure-free survival, particularly for males and younger adults.

Adolescent↗
PubMed2003

Demystified. Human endogenous retroviruses.

Human endogenous retroviruses (HERVs) are a family of viruses within our genome with similarities to present day exogenous retroviruses. HERVs have been inherited by successive generations and it is possible that some have conferred biological benefits. However, several HERVs have been implicated in certain cancers and autoimmune diseases. This article demystifies these retroviruses by providing an insight into HERVs, their means of classification, and a synopsis of HERVs implicated in cancer and autoimmunity. Furthermore, the biological roles of HERVs are explored.

Antibodies, Viral↗
PubMed2002

The Role of the Epstein-Barr virus in human disease.

EBV is a B lymphotropic virus that is associated with a range of human malignancies. Although for many of these tumours the association has long been established, unraveling the precise role of EBV in disease pathogenesis has been more difficult. This review summarizes current knowledge concerning the association between EBV and human cancers and illustrates how an increasing appreciation of patterns of latent gene expression and latent gene function in different cell environments is already helping towards a better understanding of both the natural history of infection in normal individuals and how EBV contributes to malignant transformation. Finally, therapeutic strategies that target EBV in tumours are discussed.

Carcinoma↗
PubMed2002

Acid phosphatases.

Acid phosphatases (APs) are a family of enzymes that are widespread in nature, and can be found in many animal and plant species. Mystery surrounds the precise functional role of these molecular facilitators, despite much research. Yet, paradoxically, human APs have had considerable impact as tools of clinical investigation and intervention. One particular example is tartrate resistant acid phosphatase, which is detected in the serum in raised amounts accompanying pathological bone resorption. This article seeks to explore the identity and diversity of APs, and to demonstrate the relation between APs, human disease, and clinical diagnosis.

Acid Phosphatase↗
PubMed2002

Synthetic inhibitors of CDKs induce different responses in androgen sensitive and androgen insensitive prostatic cancer cell lines.

AIMS: Because of the high prevalence of prostatic cancer and the limitations of its treatment, enormous effort has been put into the development of new therapeutic modalities. One potential tool is the use of cyclin dependent kinase (CDK) inhibitors, which are based on the trisubstituted derivatives of purine. The aim of this study was to analyse alterations of the regulatory pathways in both androgen sensitive and androgen insensitive prostatic cancer cell lines (LNCaP and DU-145, respectively) after blockage of the cell cycle by the synthetic CDK inhibitors, olomoucine and bohemine. METHODS: The effects of olomoucine and bohemine were studied on the following parameters: (1) cell proliferation, by measurement of DNA content; (2) viability, by the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) and/or XTT (2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide) test; and (3) the expression of p53, pRB, Bcl-2, Bax, p16, p21, p27, cyclins A, B, D1, E, p34(cdc2), and the androgen receptor (AR), by western blot analysis. RESULTS: Both olomoucine and bohemine were potent inhibitors of growth and viability; however, bohemine was two to three times more effective than olomoucine. The sensitivity of LNCaP cells to both agents was significantly higher. After treatment, both cell lines revealed quite different spectra of protein expression. CONCLUSIONS: These results indicate the existence of specific cell cycle regulating pathways in both cell lines, which may be associated with both p53 and AR status. CDK inhibitors exhibited valuable secondary effects on the expression of numerous regulators and thus may modulate the responsiveness of tumour cells to treatment, including treatment with hormone antagonists.

Cell Division↗
PubMed2002

Expression of c-erbB-2 in node negative breast cancer does not correlate with estrogen receptor status, predictors of hormone responsiveness, or PCNA expression.

The aim of this study was to analyse the relationships between the expression of c-erbB-2, estrogen receptor (ER), progesterone receptor (PR), Bcl-2 and PCNA in node negative breast cancer. Expression of these markers was determined by HercepTest, by immunohistochemistry and quantified by morphometry in the group of 125 selected breast carcinoma patients with broad spectrum of histological types and grades. Multivariate statistical analysis revealed only relationships between ER/PR, ER/Bcl-2, ER/grade and ER/age. There was not found any significant relationship between c-erbB-2 expression and any other immunohistochemical marker, apocrine metaplasia, histological type or patient characteristics. The same result was found in complete group of tumors as well as in individual groups divided according to histological type. These results indicate that in node negative breast tumors, c-erbB-2 expression does not correlate inversely with hormone receptor status and hormone responsiveness like previously reported metastasising breast cancer and that the prognostic significance of c-erbB-2 expression in these tumors is not clear.

Adult↗