• Analysis of circulating tumor cells in patients with non-small cell lung cancer using epithelial marker-dependent and -independent approaches.

      Krebs, Matthew G; Hou, Jian-Mei; Sloane, Robert; Lancashire, Lee J; Priest, Lynsey; Nonaka, Daisuke; Ward, Timothy H; Backen, Alison C; Clack, Glen; Hughes, Andrew; et al. (2012-02)
      Epithelial circulating tumor cells (CTCs) are detectable in patients with non-small cell lung cancer (NSCLC). However, epithelial to mesenchymal transition, a widely reported prerequisite for metastasis, may lead to an underestimation of CTC number. We compared directly an epithelial marker-dependent (CellSearch) and a marker-independent (isolation by size of epithelial tumor cells [ISET]) technology platform for the ability to identify CTCs. Molecular characteristics of CTCs were also explored.
    • Biomarkers of apoptosis.

      Ward, Timothy H; Cummings, Jeffrey; Dean, Emma J; Greystoke, Alastair; Hou, Jian-Mei; Backen, Alison C; Ranson, Malcolm R; Dive, Caroline; Clinical and Experimental Pharmacology Group, Paterson Institute for Cancer Research, University of Manchester, Manchester, UK. (2008-08-26)
      Within the era of molecularly targeted anticancer agents, it has become increasingly important to provide proof of mechanism as early on as possible in the drug development cycle, especially in the clinic. Selective activation of apoptosis is often cited as one of the major goals of cancer chemotherapy. Thus, the present minireview focuses on a discussion of the pros and cons of a variety of methodological approaches to detect different components of the apoptotic cascade as potential biomarkers of programmed cell death. The bulk of the discussion centres on serological assays utilising the technique of ELISA, since here there is an obvious advantage of sampling multiple time points. Potential biomarkers of apoptosis including circulating tumour cells, cytokeratins and DNA nucleosomes are discussed at length. However, accepting that a single biomarker may not have the power to predict proof of concept and patient outcome, it is clear that in the future more emphasis will be placed on technologies that can analyse panels of biomarkers in small volumes of samples. To this end the increased throughput afforded by multiplex ELISA technologies is discussed.British Journal of Cancer advance online publication, 26 August 2008; doi:10.1038/sj.bjc.6604519 www.bjcancer.com.
    • 'Fit-for-purpose' validation of SearchLight multiplex ELISAs of angiogenesis for clinical trial use.

      Backen, Alison C; Cummings, Jeffrey; Mitchell, Claire L; Jayson, Gordon C; Ward, Timothy H; Dive, Caroline; CR-UK Translational Angiogenesis Group, Paterson Institute for Cancer Research, University of Manchester, Wilmslow Road, Manchester, M20 4BX, UK. (2009-03-15)
      Validated assays of circulating biomarkers of angiogenesis to predict and determine the efficacy of vascular-targeted anticancer drugs would facilitate successful drug development. Multiple biomarker candidates exist and a multiplex approach was sought to minimise the requisite patient blood volume and to aid selection of those biomarkers with greatest potential clinical utility. Validation of the SearchLight multiplex ELISA platform comprising two multiplex assays of nine potential angiogenesis biomarkers was conducted (plex 1; VEGF R1 and R2, IL-8, KGF, PlGF; plex 2; PDGFbb, HGF, FGFb and VEGF). The study focused on instrument qualification, analyte specificity within the multiplex format, assay precision and reproducibility. No evidence was found within the multiplex that signals output from one analyte impinged on another or that antibody cross-reactivity occurred. Spike recovery for 5 between-experiment repeats was within +/-15% of input values for 7 of the 9 multiplexed analytes, with a coefficient of variation (CV) of <20% for 6 of the 9 analytes. Plasma samples from 8 ovarian cancer patients (who were not receiving therapy) were assessed using the two multiplexes on this platform to explore the likely baseline variability in this disease context. This study suggests that the platform and the multiplex approach will be useful to evaluate pharmacodynamic responses to vascular targeted therapy in early clinical trials.
    • Heparan sulphate synthetic and editing enzymes in ovarian cancer.

      Backen, Alison C; Cole, Claire L; Lau, Sin C; Clamp, Andrew R; McVey, Rhona J; Gallagher, John T; Jayson, Gordon C; Department of Medical Oncology, Paterson Institute for Cancer Research, Christie Hospital, Cancer Research UK and University of Manchester, Manchester M20 4BX, UK. Alison.Backen@Manchester.ac.uk (2007-05-21)
      Several angiogenic growth factors including fibroblast growth factors 1 and 2 (FGF1 and FGF2) depend on heparan sulphate (HS) for biological activity. We previously showed that all cellular elements in ovarian tumour tissue synthesised HS but biologically active HS (i.e. HS capable of binding FGF2 and its receptor) was confined to ovarian tumour endothelium. In this study, we have sought to explain this observation. Heparan sulphate sulphotransferases 1 and 2 (HS6ST1 and HS6ST2) attach sulphate groups to C-6 of glucosamine residues in HS that are critical for FGF2 activation. These enzymes were strongly expressed by tumour cells, but only HS6ST1 was found in endothelial cells. Immunostaining with the 3G10 antibody of tissue sections pretreated with heparinases indicated that HS proteoglycans were produced by tumour and endothelial cells. These results indicated that, in contrast to the endothelium, HS produced by tumour cells may be modified by cell-surface heparanase (HPA1) or endosulphatase (SULF). Protein and RNA analysis revealed that HPA1 was strongly expressed by ovarian tumour cells in eight of ten specimens examined. HSULF-1, which removes specific 6-O-sulphate groups from HS, was abundant in tumour cells but weakly expressed in the endothelium. If this enzyme was responsible for the lack of biologically active HS on the tumour cell surface, we would expect exogenous FGF2 binding to be preserved; we showed previously that this was indeed the case although FGF2 binding was reduced compared to the endothelium and stroma. Thus, the combined effects of heparanase and HSULF could account for the lack of biologically active HS in tumour cells rather than deficiencies in the biosynthetic enzymes.
    • Identification of early predictive imaging biomarkers and their relationship to serological angiogenic markers in patients with ovarian cancer with residual disease following cytotoxic therapy.

      Mitchell, Claire L; O'Connor, James P B; Jackson, A; Parker, G J M; Roberts, C; Watson, Y; Cheung, S; Davies, K; Buonaccorsi, G A; Clamp, Andrew R; et al. (2010-03-29)
      BACKGROUND: Patients with recurrent ovarian cancer often achieve partial response following chemotherapy, resulting in persistent small volume disease. After completion of treatment, the dilemma of when to initiate subsequent chemotherapy arises. Identification of biomarkers that could be used to predict when subsequent treatment is needed would be of significant benefit. Design: Twenty-three patients with advanced ovarian cancer and residual asymptomatic disease following chemotherapy underwent dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) at study entry, 4, 8, 12, 18 and 26 weeks or disease progression. A subgroup of patients provided plasma samples within which a panel of angiogenic biomarkers was quantified. RESULTS: By 4 weeks, significant differences in whole tumour volume, enhancing fraction and Ca125 were observed between patients whose disease progressed by 26 weeks and those who remained stable. Significant correlations between plasma soluble vascular endothelial growth factor recptor-1 (sVEGFR-1) and sVEGFR-2 concentrations, and blood volume and tumour endothelial permeability surface area product measured by DCE-MRI were observed. CONCLUSIONS: Imaging markers have a potential role in early prediction of disease progression in patients with residual ovarian cancer and may supplement current measures of progression. The correlation of DCE-MRI and serological biomarkers suggests that tumour angiogenesis affects these markers through common biological means and warrants further investigation.
    • Inhibition of FGFR2 and FGFR1 increases cisplatin sensitivity in ovarian cancer.

      Cole, Claire L; Lau, Sin; Backen, Alison C; Clamp, Andrew R; Rushton, Graham; Dive, Caroline; Hodgkinson, Cassandra L; McVey, Rhona J; Kitchener, Henry C; Jayson, Gordon C; et al. (2010-09-04)
      Fibroblast Growth Factors (FGFs) have been implicated in malignant transformation, tumor mitogenesis, angiogenesis and chemoresistance. The aim of this study was to determine which FGFs and FGFRs play functional roles in epithelial ovarian cancer. Restriction enzyme analysis of mRNA revealed that transformation was associated with a switch in FGFR2 and FGFR3, from the IIIc to the IIIb isoform. There was widespread expression of FGFs, including FGF7, in all tissues but, FGF3 and FGF19 were expressed by malignant cell lines and cancer tissue but were not present in normal tissue. Using FGFR-specific shRNAi we demonstrated that reductions in FGFR2 inhibited proliferation of ovarian cancer cell lines in vitro (>50%, p < 0.006) and reduced cisplatin IC(50) (>60%, p < 0.0001). Cell cycle analysis revealed increased cisplatin sensitivity was associated with increased G(2)/M arrest and increased apoptosis. FGFR2 shRNAi reduced growth rates of ovarian tumor xenografts by 20% (p > 0.006) and when combined with cisplatin caused a 40% reduction in proliferation rates (p < 0.007). In contrast, RNAi-induced reductions in FGFR1 increased SKOV3 cell numbers, with associated changes in cell cycle but had no effect on ES2 cells. However, the cisplatin IC(50) was reduced (>50%, p < 0.0001) by FGFR1 shRNAi in both cell lines and there was increased apoptosis (46-50%) compared with control cells (35%) (p > 0.004). Together our data suggest that combining FGFR2 inhibitors with platinum-containing cytotoxic agents for the treatment of epithelial ovarian cancer may yield increased anti-tumor activity. However, data on the inhibition of FGFR1 suggest that broad spectrum FGFR inhibitors may have unexpected effects on proliferation.
    • Issues on fit-for-purpose validation of a panel of ELISAs for application as biomarkers in clinical trials of anti-Angiogenic drugs.

      Brookes, K E; Cummings, Jeffrey; Backen, Alison C; Greystoke, Alastair; Ward, Timothy H; Jayson, Gordon C; Dive, Caroline; Clinical and Experimental Pharmacology Group, Paterson Institute for Cancer Research, University of Manchester, Manchester M20 4BX, UK. (2010-05-11)
      BACKGROUND: Successful introduction of new anticancer agents into the clinic is often hampered by a lack of qualified biomarkers. Studies have been conducted of 17 ELISAs representing a potential panel of pharmacodynamic/predictive biomarkers for drugs targeted to tumour vasculature. METHODS: The fit-for-purpose approach to method validation was used. Stability studies were performed using recombinant proteins in surrogate matrices, endogenous analytes in healthy volunteer and cancer patient plasma. The impact of platelet depletion was investigated. RESULTS: Method validation focused on measuring precision and showed that 15 of the 17 assays were within acceptable limits. Stability at -80 degrees C was shown for 3 months with all recombinant proteins in surrogate matrices, whereas under the same conditions instability was observed with KGF in platelet-rich and platelet-depleted plasma, and with PDGF-BB in platelet-depleted plasma from cancer patients. For measurement of extracellular circulating analytes, platelet depletion should be conducted before freezing of plasma to prevent release of PDGF-BB, FGFb and VEGF-A. A protocol was developed to remove >90% platelets from plasma requiring centrifugation at 2000 g for 25 min. CONCLUSIONS: These studies highlight the need for assay validation and crucial assessment of sample handling issues before commencement of biomarker analysis in clinical trials.
    • The molecular phenotype of heparan sulfate in the Hs2st-/- mutant mouse.

      Merry, Catherine L R; Bullock, Simon L; Swan, Daniel C; Backen, Alison C; Lyon, Malcolm; Beddington, Rosa S; Wilson, Valerie A; Gallagher, John T; Cancer Research Campaign Department of Medical Oncology, Christie Hospital NHS Trust, Manchester M20 4BX, United Kingdom. cmerry@picr.man.ac.uk (2001-09-21)
      Heparan sulfate (HS) is a co-receptor for a number of growth factors, morphogens, and adhesion proteins. HS biosynthetic modifications may determine the strength and outcome of HS-ligand interactions. We previously described the phenotype of mice with a gene-trap mutation in Hs2st, encoding the key HS 2-O-sulfotransferase enzyme in HS polymer modification. In contrast to the early developmental failure of embryos lacking HS, the onset of abnormalities in the Hs2st(-/-) mice occurs only after midgestation, the most dramatic being the complete failure of kidney development. Uronate 2-O-sulfates were not detected in the mutant HS, indicating a complete loss of function of Hs2st. However, the domain structure of the mutant HS is conserved, and compensatory increases in N- and 6-O-sulfation maintain the overall charge density. The apparent affinities of the mutant HS for hepatocyte growth factor/scatter factor and fibronectin were unchanged but were reduced for fibroblast growth factor-1 and -2. Surprisingly, the Hs2st(-/-) cells were able to mount an apparently normal signaling response to fibroblast growth factor-1 and -2 as well as to hepatocyte growth factor/scatter factor.
    • A pilot study to explore circulating tumour cells in pancreatic cancer as a novel biomarker.

      Khoja, Leila; Backen, Alison C; Sloane, Robert; Menasce, Lia P; Ryder, W David J; Krebs, Matthew G; Board, Ruth E; Clack, G; Hughes, A; Blackhall, Fiona H; et al. (2012-01-31)
      Obtaining tissue for pancreatic carcinoma diagnosis and biomarker assessment to aid drug development is challenging. Circulating tumour cells (CTCs) may represent a potential biomarker to address these unmet needs. We compared prospectively the utility of two platforms for CTC enumeration and characterisation in pancreatic cancer patients in a pilot exploratory study.
    • Regulation of fibroblast growth factor-2 activity by human ovarian cancer tumor endothelium.

      Whitworth, Melissa K; Backen, Alison C; Clamp, Andrew R; Wilson, Godfrey E; McVey, Rhona J; Friedl, Andreas; Rapraeger, Alan C; David, Guido; McGown, Alan T; Slade, Richard J; et al. (2005-06-15)
      Fibroblast growth factor-2 (FGF-2) is a potent angiogenic cytokine that is dependent on heparan sulfate for its biological activity. We have investigated the relationship among heparan sulfate, FGF-2, and the signal-transducing receptors in human, advanced-stage, serous ovarian adenocarcinoma. Using a unique molecular probe, FR1c-Ap, which consisted of a soluble FGF receptor 1 isoform IIIc covalently linked to an alkaline phosphatase moiety, the distribution of heparan sulfate that had the ability to support the formation of a heparan sulfate/FGF-2/FGFR1 isoform IIIc alkaline phosphatase heparan sulfate construct complex was determined. This may be taken as a surrogate marker for the distribution of biologically active heparan sulfate and was distributed predominantly in endothelial cells and stroma but was absent from adenocarcinoma cells. In situ hybridization revealed the expression of FGFR1 mRNA in the endothelium and reverse transcription-PCR confirmed the presence of FGFR1 isoform IIIc but not isoform IIIb. The presence of FGF-2 around tumor endothelium was detected through immunohistochemistry. Double-staining techniques showed that heparan sulfate was found predominantly at the basal aspect of the endothelium and suggested that syndecan-3 might function as one of the proteoglycans involved in FGF-2 signaling in the endothelium. The data suggest that the entire extracellular signaling apparatus, consisting of FGF-2, biologically active heparan sulfate, and FGFRs capable of responding to FGF-2, is present in ovarian cancer endothelium, thereby highlighting the cytokine and its cognate receptor as potential targets for the antiangiogenic treatment of this disease.