Laminin production by murine melanoma cells: possible involvement in cell motility

Three lines of B16 melanoma cells (B16-F1, B16-F10 and B16-BL6) were examined for motility in the micropore filter assay and for synthesis in culture of the basal lamina glycoprotein laminin. All three lines synthesized laminin as judged by the incorporation of [ 35 S]methionine into immunoreactive laminin and secreted (or shed) laminin into the culture medium as indicated by biosynthetic labeling studies and enzyme-linked immunosorbent assays. Immunoreactive laminin was also seen on the surface of the cells as indicated by immunofluorescence staining and by complement-mediated killing. Analysis of [ 35 S]methionine-labeled laminin immunoprecipitates by sodium dodecylsulfatepolyacrylamide gel electrophoresis (SDS-PAGE) both with and without reduction of intersubunit disulfide bonds revealed that all three cell lines produced a similar array of laminin forms, and that the M r =950kD laminin molecule (but not the uncombined subunits) was secreted into the culture medium. Laminin biosynthesis appeared to be limited by the availability of the M r =400kD A subunit as shown by the intracellular accumulation of excess B subunit in the form of uncombined B subunit ( M r =200kD) and as a disulfide-linked B dimer ( M r =400 kD). The motility of all three cell lines was stimulated four- to five-fold by the addition of either exogenous laminin from the EHS sarcoma or culture medium from the B16 cells containing the secreted laminin. The stimulated motility was inhibited by antilaminin serum. These observations suggest that the laminin synthesized by the B16 melanoma cells themselves may facilitate their motility.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42594/1/10585_2004_Article_BF00133591.pd

Bankruptcy Treatment of Intellectual Property Assets: An Economic Analysis

With the rise of intellectual property in the modern economy, bankruptcy treatment of intellectual property assets has taken on ever greater importance. The law in this area must balance different approaches to asset management. Viewing the world from an ex ante perspective, intellectual property laws seek to foster investment in research and development. Freedom of contract plays a central role in maximizing the potential value of intellectual property by encouraging a robust licensing market to exploit the value of intellectual creativity. By contrast, the bankruptcy system generally views asset management from an ex post standpoint, focusing narrowly on how to maximize the value of a failing or failed enterprise. Thus, bankruptcy law affords trustees and debtors substantial leeway to rescind contracts and reorder the affairs of the failed entity. This article examines the rather complex rules governing the treatment of intellectual property assets in bankruptcy and suggests various reforms that could better promote economic efficiency