Project description:Extracellular matrix interactions play essential roles in normal physiology and many pathological processes. Here, we report a novel screening platform capable of measuring phenotypic responses to combinations of ECM molecules. While the importance of ECM interactions in metastasis is well documented, systematic approaches to identify their roles in distinct stages of tumorigenesis have not been described. Using a genetic mouse model of lung adenocarcinoma, we measured the ECM-dependent adhesion of tumor-derived cells. Hierarchical clustering of adhesion profiles generated using this platform differentially segregated metastatic cell lines from primary tumor lines. Furthermore, we uncovered that metastatic cells selectively associate with fibronectin when in combination with galectin-3, galectin-8, or laminin. These interactions appear to be mediated in part by α3β1 integrin both in vitro and in vivo. We show that these galectins also correlate with human disease at both a transcriptional and histological level. Thus, our in vitro platform allowed us to interrogate the interactions of metastatic cells with their surrounding environment, and identified ECM and integrin interactions that could lead to therapeutic targets for metastasis prevention. Cell lines derived from murine lung primary adenocarcinomas and their metastases (Winslow et al., 2011 Nature 473:101-104)
Project description:Extracellular matrix interactions play essential roles in normal physiology and many pathological processes. Here, we report a novel screening platform capable of measuring phenotypic responses to combinations of ECM molecules. While the importance of ECM interactions in metastasis is well documented, systematic approaches to identify their roles in distinct stages of tumorigenesis have not been described. Using a genetic mouse model of lung adenocarcinoma, we measured the ECM-dependent adhesion of tumor-derived cells. Hierarchical clustering of adhesion profiles generated using this platform differentially segregated metastatic cell lines from primary tumor lines. Furthermore, we uncovered that metastatic cells selectively associate with fibronectin when in combination with galectin-3, galectin-8, or laminin. These interactions appear to be mediated in part by α3β1 integrin both in vitro and in vivo. We show that these galectins also correlate with human disease at both a transcriptional and histological level. Thus, our in vitro platform allowed us to interrogate the interactions of metastatic cells with their surrounding environment, and identified ECM and integrin interactions that could lead to therapeutic targets for metastasis prevention.
Project description:To characterize the genetic basis of hybrid male sterility in detail, we used a systems genetics approach, integrating mapping of gene expression traits with sterility phenotypes and QTL. We measured genome-wide testis expression in 305 male F2s from a cross between wild-derived inbred strains of M. musculus musculus and M. m. domesticus. We identified several thousand cis- and trans-acting QTL contributing to expression variation (eQTL). Many trans eQTL cluster into eleven ‘hotspots,’ seven of which co-localize with QTL for sterility phenotypes identified in the cross. The number and clustering of trans eQTL - but not cis eQTL - were substantially lower when mapping was restricted to a ‘fertile’ subset of mice, providing evidence that trans eQTL hotspots are related to sterility. Functional annotation of transcripts with eQTL provides insights into the biological processes disrupted by sterility loci and guides prioritization of candidate genes. Using a conditional mapping approach, we identified eQTL dependent on interactions between loci, revealing a complex system of epistasis. Our results illuminate established patterns, including the role of the X chromosome in hybrid sterility.
