Molecular Signatures of Prostate Stem Cells Reveal Novel Signaling Pathways and Provide Insights into Prostate Cancer

BACKGROUND:The global gene expression profiles of adult and fetal murine prostate stem cells were determined to define common and unique regulators whose misexpression might play a role in the development of prostate cancer. METHODOLOGY/PRINCIPAL FINDINGS:A distinctive core of transcriptional regulators common to both fetal and adult primitive prostate cells was identified as well as molecules that are exclusive to each population. Elements common to fetal and adult prostate stem cells include expression profiles of Wnt, Shh and other pathways identified in stem cells of other organs, signatures of the aryl-hydrocarbon receptor, and up-regulation of components of the aldehyde dehydrogenase/retinoic acid receptor axis. There is also a significant lipid metabolism signature, marked by overexpression of lipid metabolizing enzymes and the presence of the binding motif for Srebp1. The fetal stem cell population, characterized by more rapid proliferation and self-renewal, expresses regulators of the cell cycle, such as E2f, Nfy, Tead2 and Ap2, at elevated levels, while adult stem cells show a signature in which TGF-beta has a prominent role. Finally, comparison of the signatures of primitive prostate cells with previously described profiles of human prostate tumors identified stem cell molecules and pathways with deregulated expression in prostate tumors including chromatin modifiers and the oncogene, Erg. CONCLUSIONS/SIGNIFICANCE:Our data indicate that adult prostate stem or progenitor cells may acquire characteristics of self-renewing primitive fetal prostate cells during oncogenesis and suggest that aberrant activation of components of prostate stem cell pathways may contribute to the development of prostate tumors

Measuring Success Factors of Quality Management in the Shipping Industry

It is generally accepted that quality management is considered a valuable competitive factor for firms that confers them competitive advantages and enables them to achieve superior performance. Although there have been numerous studies examining general quality management practices and implementation, industry-specific studies on quality management practices and factors that influence their success in the shipping industry are rather few. This study seeks to identify the factors that are critical to successful quality management, and attempts to develop a reliable, empirically tested, and rigorously validated measurement instrument for quality management, for the shipping industry. We conducted a large-scale survey of shipping industry executives and applied a rigorous research methodology to treat the survey data. We identified four success factors of quality management, which are top management commitment and participation, quality information and performance measurement, employee training and empowerment, and customer focus, and developed a functional instrument to measure quality management in the shipping industry. This paper contributes to research by identifying the success factors of quality management, and provides managerial insights on the successful management of quality, in the shipping industry. Maritime Economics & Logistics (2007) 9, 234–253. doi:10.1057/palgrave.mel.9100179