@article {49740, title = {Global secretome analysis identifies novel mediators of bone metastasis.}, journal = {Cell Res}, volume = {22}, year = {2012}, month = {2012 Sep}, pages = {1339-55}, abstract = {

Bone is the one of the most common sites of distant metastasis of solid tumors. Secreted proteins are known to influence pathological interactions between metastatic cancer cells and the bone stroma. To comprehensively profile secreted proteins associated with bone metastasis, we used quantitative and non-quantitative mass spectrometry to globally analyze the secretomes of nine cell lines of varying bone metastatic ability from multiple species and cancer types. By comparing the secretomes of parental cells and their bone metastatic derivatives, we identified the secreted proteins that were uniquely associated with bone metastasis in these cell lines. We then incorporated bioinformatic analyses of large clinical metastasis datasets to obtain a list of candidate novel bone metastasis proteins of several functional classes that were strongly associated with both clinical and experimental bone metastasis. Functional validation of selected proteins indicated that in vivo bone metastasis can be promoted by high expression of (1) the salivary cystatins CST1, CST2, and CST4; (2) the plasminogen activators PLAT and PLAU; or (3) the collagen functionality proteins PLOD2 and COL6A1. Overall, our study has uncovered several new secreted mediators of bone metastasis and therefore demonstrated that secretome analysis is a powerful method for identification of novel biomarkers and candidate therapeutic targets.

}, keywords = {Animals, Biomarkers, Tumor, Bone Neoplasms, Cell Line, Tumor, Collagen Type VI, Computational Biology, HUMANS, Mass Spectrometry, Mice, Neoplasms, Plasminogen Activators, Procollagen-Lysine, 2-Oxoglutarate 5-Dioxygenase, Proteome, proteomics, Salivary Cystatins}, issn = {1748-7838}, doi = {10.1038/cr.2012.89}, author = {Blanco, Mario Andres and LeRoy, Gary and Khan, Zia and Ale{\v c}kovi{\'c}, Ma{\v s}a and Zee, Barry M and Garcia, Benjamin A and Kang, Yibin} } @article {49548, title = {Quantitative measurement of allele-specific protein expression in a diploid yeast hybrid by LC-MS.}, volume = {8}, year = {2012}, month = {2012}, pages = {602}, abstract = {

Understanding the genetic basis of gene regulatory variation is a key goal of evolutionary and medical genetics. Regulatory variation can act in an allele-specific manner (cis-acting) or it can affect both alleles of a gene (trans-acting). Differential allele-specific expression (ASE), in which the expression of one allele differs from another in a diploid, implies the presence of cis-acting regulatory variation. While microarrays and high-throughput sequencing have enabled genome-wide measurements of transcriptional ASE, methods for measurement of protein ASE (pASE) have lagged far behind. We describe a flexible, accurate, and scalable strategy for measurement of pASE by liquid chromatography-coupled mass spectrometry (LC-MS). We apply this approach to a hybrid between the yeast species Saccharomyces cerevisiae and Saccharomyces bayanus. Our results provide the first analysis of the relative contribution of cis-acting and trans-acting regulatory differences to protein expression divergence between yeast species.

}, keywords = {Alleles, Chromatography, Liquid, Fungal Proteins, Gene Expression Profiling, Gene Expression Regulation, Fungal, HUMANS, Mass Spectrometry, proteomics, Regression Analysis, Saccharomyces, Saccharomyces cerevisiae, Saccharomyces cerevisiae Proteins, Species Specificity}, issn = {1744-4292}, doi = {10.1038/msb.2012.34}, author = {Khan, Zia and Bloom, Joshua S and Amini, Sasan and Singh, Mona and Perlman, David H and Caudy, Amy A and Kruglyak, Leonid} } @article {49744, title = {Accurate proteome-wide protein quantification from high-resolution 15N mass spectra.}, journal = {Genome Biol}, volume = {12}, year = {2011}, month = {2011}, pages = {R122}, abstract = {

In quantitative mass spectrometry-based proteomics, the metabolic incorporation of a single source of 15N-labeled nitrogen has many advantages over using stable isotope-labeled amino acids. However, the lack of a robust computational framework for analyzing the resulting spectra has impeded wide use of this approach. We have addressed this challenge by introducing a new computational methodology for analyzing 15N spectra in which quantification is integrated with identification. Application of this method to an Escherichia coli growth transition reveals significant improvement in quantification accuracy over previous methods.

}, keywords = {algorithms, Amino Acid Sequence, Bacterial Proteins, Escherichia coli, Isotope Labeling, Mass Spectrometry, Molecular Sequence Data, Nitrogen Isotopes, Proteome, proteomics, Sensitivity and Specificity, software}, issn = {1474-760X}, doi = {10.1186/gb-2011-12-12-r122}, author = {Khan, Zia and Amini, Sasan and Bloom, Joshua S and Ruse, Cristian and Caudy, Amy A and Kruglyak, Leonid and Singh, Mona and Perlman, David H and Tavazoie, Saeed} } @article {49746, title = {Direct targeting of Sec23a by miR-200s influences cancer cell secretome and promotes metastatic colonization.}, journal = {Nat Med}, volume = {17}, year = {2011}, month = {2011 Sep}, pages = {1101-8}, abstract = {

Although the role of miR-200s in regulating E-cadherin expression and epithelial-to-mesenchymal transition is well established, their influence on metastatic colonization remains controversial. Here we have used clinical and experimental models of breast cancer metastasis to discover a pro-metastatic role of miR-200s that goes beyond their regulation of E-cadherin and epithelial phenotype. Overexpression of miR-200s is associated with increased risk of metastasis in breast cancer and promotes metastatic colonization in mouse models, phenotypes that cannot be recapitulated by E-cadherin expression alone. Genomic and proteomic analyses revealed global shifts in gene expression upon miR-200 overexpression toward that of highly metastatic cells. miR-200s promote metastatic colonization partly through direct targeting of Sec23a, which mediates secretion of metastasis-suppressive proteins, including Igfbp4 and Tinagl1, as validated by functional and clinical correlation studies. Overall, these findings suggest a pleiotropic role of miR-200s in promoting metastatic colonization by influencing E-cadherin-dependent epithelial traits and Sec23a-mediated tumor cell secretome.

}, keywords = {Animals, Cadherins, Cell Line, Tumor, Female, Gene Expression Profiling, Gene Expression Regulation, Neoplastic, HUMANS, Mass Spectrometry, Mice, Mice, Inbred BALB C, Microarray Analysis, MicroRNAs, Neoplasm Metastasis, Statistics, Nonparametric, Vesicular Transport Proteins}, issn = {1546-170X}, doi = {10.1038/nm.2401}, author = {Korpal, Manav and Ell, Brian J and Buffa, Francesca M and Ibrahim, Toni and Blanco, Mario A and Celi{\`a}-Terrassa, Toni and Mercatali, Laura and Khan, Zia and Goodarzi, Hani and Hua, Yuling and Wei, Yong and Hu, Guohong and Garcia, Benjamin A and Ragoussis, Jiannis and Amadori, Dino and Harris, Adrian L and Kang, Yibin} }