Reovirus exerts potent oncolytic effects in head and neck cancer cell lines that are independent of signalling in the EGFR pathway

Background: reovirus exploits aberrant signalling downstream of Ras to mediate tumor-specific oncolysis. Since ~90% squamous cell carcinomas of the head and neck (SCCHN) over-express EGFR and SCCHN cell lines are sensitive to oncolytic reovirus, we conducted a detailed analysis of the effects of reovirus in 15 head and neck cancer cell lines. Both pre- and post-entry events were studied in an attempt to define biomarkers predictive of sensitivity/resistance to reovirus. In particular, we analysed the role of EGFR/Ras signalling in determining virus-mediated cytotoxicity in SCCHN. Methods: to test whether EGFR pathway activity was predictive of increased sensitivity to reovirus, correlative analyses between reoviral IC50 by MTT assay and EGFR levels by western blot and FACS were conducted. Inhibition or stimulation of EGFR signalling were analysed for their effect on reoviral oncolysis by MTT assay, and viral growth by TCID50 assay. We next analysed the effects of inhibiting signalling downstream of Ras, by specific inhibitors of p38MAPK, PI3-K or MEK, on reoviral killing examined by MTT assay. The role of PKR in reoviral killing was also determined by blockade of PKR using 2-aminopurine and assaying for cell survival by MTT assay. The apoptotic response of SCCHN to reovirus was examined by western blot analysis of caspase 3 cleavage. Results: correlative analyses between reoviral sensitivity and EGFR levels revealed no association. Intermediate sub-viral and core particles showed the same infectivity/cytotoxicity as intact reovirus. Therefore, sensitivity was not determined by cell entry. In 4 cell lines, oncolysis and viral growth were both unaffected by inhibition or stimulation of EGFR signalling. Inhibition of signalling downstream of Ras did not abrogate reoviral oncolysis and, in addition, modulation of PKR using 2-aminopurine did not alter reovirus sensitivity in resistant cell lines. Caspase 3 cleavage was not detected in infected cells and oncolysis was observed in pan-caspase inhibited cells. Conclusions: in summary, reovirus is potently oncolytic in a broad panel of SCCHN cell lines. Attempts to define sensitivity/resistance by analysis of the EGFR/Ras/MAPK pathway have failed to provide a clear predictive biomarker of response. Further analysis of material from in vitro and clinical studies is ongoing in an attempt to shed further light on this issue

Genetic Analysis of von Hippel-Lindau Disease

Mutations in the von Hippel-Lindau (VHL) gene are responsible for VHL disease, congenital polycythemia, and are found in many sporadic tumor types as well. Reports of VHL mutations are dispersed throughout original articles and databases that have not been recently updated. We compiled a comprehensive mutation table of 1,548 germline and somatic VHL mutations, derived from this protein of only 213 amino acids. We describe detailed phenotype and gene mutation information for 945 VHL families, including 30 previously unpublished kindreds from The Netherlands (six novel mutations). These data represent the most extensive catalog of germline VHL mutations to date. We also review VHL disease, known and theorized pathogenesis of common VHL manifestations, and genotype phenotype correlations. Analysis of all VHL families, excluding germline mutations resulting in congenital polycythemias, describes the spectrum of mutation types: 52% missense, 13% frameshift, 11% nonsense, 6% in-frame deletions/insertions, 11% large/complete deletions, and 7% splice mutations. This easy-to-use compilation of VHL mutations is intended to facilitate research and function as a necessary adjunct for physicians when providing patient information. Hum Mutat 31:521-537, 2010. (C) 2010 Wiley-Liss, Inc

ESMO Clinical Research Observatory (ECRO): improving the efficiency of clinical research through rationalisation of bureaucracy

During the last years, there has been a dramatic increase in the administrative and bureaucratic burden associated with clinical research, which has clearly had an impact on its overall efficiency and on the activity of clinical investigators and research teams. Indeed, the supervision of the adherence of clinical research to Good Clinical Practice (GCP) guidelines and legal regulations is of the utmost importance. Yet, while such regulations have remained largely unchanged during recent years, the number of administrative tasks and their complexity have grown markedly, as supported by the results of a survey performed among 940 clinical investigators that we report in this manuscript. Therefore, many investigators believe that it has become necessary to undertake a rigorous analysis of the causes and consequences of this issue, and to create a conduit to channel the advice from experienced investigators regarding clinical research procedures, in order to improve them. Based on these premises, ESMO has launched the ESMO Clinical Research Observatory (ECRO), a task force that will analyse different aspects of clinical research. ECRO will aim to provide the views of ESMO on clinical research procedures based on the feedback from clinical investigators, under complete adherence to the Declaration of Helsinki, the GCP guidelines and any other applicable legal regulations, while at the same time showing profound respect for all the stakeholders involved in clinical research. This manuscript provides the background and rationale for the creation of ECRO, its planned activity and an analysis of the current administrative burden in clinical research with recommendations to rationalise it. Indeed, we expect that this effort shall lead to a relevant improvement in the care of patients and in the development of clinical research

Preferences for genetic testing for colorectal cancer within a population-based screening program: a discrete choice experiment

This study explored individuals' preferences for genetic testing for colorectal cancer (CRC) in a screening situation and their willingness to participate in genetic testing for Lynch syndrome, familial adenomatous polyposis (FAP), and familial colorectal cancer (FCC). For that purpose, 532 respondents aged 55-65 years completed a Discrete Choice Experiment. Using panel latent class models, the preferences for two screening situation characteristics (the probability of being genetically predisposed and the probability of developing CRC) and screening test characteristics (the frequency of preventive colonoscopies and CRC survival) were estimated. Based on these preferences, respondents' willingness to participate in the three screening initiatives was estimated. Lower-educated respondents and respondents who express serious anxiety and worries found colonoscopy frequency and the probability of developing CRC relatively more important and survival relatively less important compared with higher-educated respondents and respondents who express no anxiety and worries. These differences in preferences resulted in opposite preferences for participation in FCC and FAP screening. In conclusion, the general population is willing to participate in genetic screening for CRC. If individuals are suspected of genetic or familial CRC, they should at least be informed about their increased risk of being genetically predisposed and about the importance of participating in all preventive follow-up colonoscopies in order to maximize survival

VHL loss causes spindle misorientation and chromosome instability

Error-free mitosis depends on fidelity-monitoring checkpoint systems that ensure correct temporal and spatial coordination of chromosome segregation by the microtubule spindle apparatus. Defects in these checkpoint systems can lead to genomic instability, an important aspect of tumorigenesis. Here we show that the von Hippel-Lindau (VHL) tumour suppressor protein, pVHL, which is inactivated in hereditary and sporadic forms of renal cell carcinoma, localizes to the mitotic spindle in mammalian cells and its functional inactivation provokes spindle misorientation, spindle checkpoint weakening and chromosomal instability. Spindle misorientation is linked to unstable astral microtubules and is supressed by the restoration of wild-type pVHL in pVHL-deficient cells, but not in naturally-occurring VHL disease mutants that are defective in microtubule stabilization. Impaired spindle checkpoint function and chromosomal instability are the result of reduced Mad2 (mitotic arrest deficient 2) levels actuated by pVHL-inactivation and are rescued by re-expression of either Mad2 or pVHL in VHL-defective cells. An association between VHL inactivation, reduced Mad2 levels and increased aneuploidy was also found in human renal cancer, implying that the newly identified functions of pVHL in promoting proper spindle orientation and chromosomal stability probably contribute to tumour suppression

pVHL and GSK3beta are components of a primary cilium-maintenance signalling network

Defects in the structure or function of the primary cilium, an antennae-like structure whose functional integrity has been linked to the suppression of uncontrolled kidney epithelial cell proliferation, are a common feature of genetic disorders characterized by kidney cysts. However, the mechanisms by which primary cilia are maintained remain poorly defined. von Hippel-Lindau (VHL) disease is characterized by the development of premalignant renal cysts and arises because of functional inactivation of the VHL tumour suppressor gene product, pVHL. Here, we show that pVHL and glycogen synthase kinase (GSK)3beta are key components of an interlinked signalling pathway that maintains the primary cilium. Although inactivation of either pVHL or GSK3beta alone did not affect cilia maintenance, their combined inactivation leads to loss of cilia. In VHL patients, GSK3beta is subjected to inhibitory phosphorylation in renal cysts, but not in early VHL mutant lesions, and these cysts exhibit reduced frequencies of primary cilia. We propose that pVHL and GSK3beta function together in a ciliary-maintenance signalling network, disruption of which enhances the vulnerability of cells to lose their cilia, thereby promoting cyst formation