Description: Objectives Novel imaging methods based on specific molecular targets to detect both established neoplasms and their precursor lesions are highly desirable in cancer medicine. Previously, we identified claudin-4, an integral constituent of tight junctions, as highly expressed in various gastrointestinal tumours including pancreatic cancer. Here, we investigate the potential of targeting claudin-4 with a naturally occurring ligand to visualise pancreatic cancer and its precursor lesions in vitro and in vivo by near-infrared imaging approaches. Design A non-toxic C-terminal fragment of the claudin-4 ligand Clostridium perfringens enterotoxin (C-CPE) was labelled with a cyanine dye (Cy5.5). Binding of the optical tracer was analysed on claudin-4 positive and negative cells in vitro, and tumour xenografts in vivo. In addition, two genetically engineered mouse models for pancreatic intraepithelial neoplasia (PanIN) and pancreatic cancer were used for in vivo validation. Optical imaging studies were conducted using 2D planar fluorescence reflectance imaging (FRI) technology and 3D fluorescence-mediated tomography (FMT). Results In vitro, the peptide-dye conjugate showed high binding affinity to claudin-4 positive CAPAN1 cells, while claudin-4 negative HT1080 cells revealed little or no fluorescence. In vivo, claudin-4 positive tumour xenografts, endogenous pancreatic tumours, hepatic metastases, as well as preinvasive PanIN lesions, were visualised by FRI and FMT up to 48 h after injection showing a significantly higher average of fluorochrome concentration as compared with claudin-4 negative xenografts and normal pancreatic tissue. Conclusions C-CPE-Cy5.5 combined with novel optical imaging methods enables non-invasive visualisation of claudin-4 positive murine pancreatic tumours and their precursor lesions, representing a promising modality for early diagnostic imaging.

Description: Cancer stem cells (CSC) have been implicated in disease recurrence, metastasis, and therapeutic resistance, but effective targeting strategies for these cells are still wanting. VS-5584 is a potent and selective dual inhibitor of mTORC1/2 and class I PI 3-kinases. Here, we report that VS-5584 is up to 30-fold more potent in inhibiting the proliferation and survival of CSC compared with non-CSC in solid tumor cell populations. VS-5584 preferentially diminished CSC levels in multiple mouse xenograft models of human cancer, as evidenced by marked reduction of tumor-initiating capacity in limiting dilution assays. Likewise, VS-5584 treatment ex vivo preferentially reduced CSC in surgically resected breast and ovarian patient tumors. In contrast, chemotherapeutics such as paclitaxel and cisplatin were less effective in targeting CSC than bulk tumor cells. Mechanistic investigations revealed that preferential targeting of CSC required inhibition of multiple components of the PI3K–mTOR pathway: coordinate RNAi-mediated silencing of PI3Kα, PI3Kβ, and mTOR phenocopied the effect of VS-5584, exhibiting the strongest preferential targeting of CSC, while silencing of individual PI3K isoforms or mTOR failed to replicate the effect of VS-5584. Consistent with CSC ablation, VS-5584 delayed tumor regrowth following chemotherapy in xenograft models of small-cell lung cancer. Taken together, the preferential targeting of CSC prompts a new paradigm for clinical testing of VS-5584: clinical trials designed with CSC-directed endpoints may facilitate demonstration of the therapeutic benefit of VS-5584. We suggest that combining VS-5584 with classic chemotherapy that debulks tumors may engender a more effective strategy to achieve durable remissions in patients with cancer. Cancer Res; 75(2); 446–55. ©2014 AACR.

Description: Proline-rich tyrosine kinase 2 (Pyk2) is a member of the focal adhesion kinase family that has been recently linked to tumor development. However, its role in modulating multiple myeloma (MM) biology and disease progression remains unexplored. We first demonstrated that patients with MM present with higher expression of Pyk2 compared with healthy individuals. By using loss-of-function approaches, we found that Pyk2 inhibition led to reduction of MM tumor growth in vivo as well as decreased cell proliferation, cell-cycle progression, and adhesion ability in vitro. In turn, overexpression of Pyk2 promoted the malignant phenotype, substantiated by enhanced tumor growth and reduced survival. Mechanistically, inhibition of Pyk2 reduced activation of Wnt/β-catenin signaling by destabilizing β-catenin, leading to downregulation of c-Myc and Cyclin D1. Furthermore, treatment of MM cells with the FAK/Pyk2 inhibitor VS-4718 effectively inhibited MM cell growth both in vitro and in vivo. Collectively, our findings describe the tumor-promoting role of Pyk2 in MM, thus providing molecular evidence for a novel tyrosine kinase inhibitor as a new therapeutic option in MM.

Description: Designing and implementing high-quality health care services and interventions requires robustly synthesised evidence. Syntheses of qualitative research studies can provide evidence of patients’ experiences of...

Description: Background: Designing and implementing high-quality health care services and interventions requires robustly synthesised evidence. Syntheses of qualitative research studies can provide evidence of patients’ experiences of health conditions; intervention feasibility, appropriateness and acceptability to patients; and advance understanding of health care issues. The unique, interpretive, theory-based meta-ethnography synthesis approach is suited to conveying patients’ views and developing theory to inform service design and delivery. However, meta-ethnography reporting is often poor quality, which discourages trust in, and use of, meta-ethnography findings. Users of evidence syntheses require reports that clearly articulate analytical processes and findings. Tailored research reporting guidelines can raise reporting standards but none exists for meta-ethnography. This study aims to create an evidence-based meta-ethnography reporting guideline articulating the methodological standards and depth of reporting required to improve reporting quality.Methods/designThe mixed-methods design of this National Institute of Health Research-funded study (http://www.stir.ac.uk/emerge/) follows good practice in research reporting guideline development comprising: (1) a methodological systematic review (PROSPERO registration: CRD42015024709) to identify recommendations and guidance in conducting/reporting meta-ethnography; (2) a review and audit of published meta-ethnographies to identify good practice principles and develop standards in conduct/reporting; (3) an online workshop and Delphi studies to agree guideline content with 45 international qualitative synthesis experts and 45 other stakeholders including patients; (4) development and wide dissemination of the guideline and its accompanying detailed explanatory document, a report template for National Institute of Health Research commissioned meta-ethnographies, and training materials on guideline use.DiscussionMeta-ethnography, devised in the field of education, is now used widely in other disciplines. Methodological advances relevant to meta-ethnography conduct exist. The extent of discipline-specific adaptations of meta-ethnography and the fit of any adaptions with the underpinning philosophy of meta-ethnography require investigation. Well-reported meta-ethnography findings could inform clinical decision-making. A bespoke meta-ethnography reporting guideline is needed to improve reporting quality, but to be effective potential users must know it exists, trust it and use it. Therefore, a rigorous study has been designed to develop and promote a guideline. By raising reporting quality, the guideline will maximise the likelihood that high-quality meta-ethnographies will contribute robust evidence to improve health care and patient outcomes.