Under hypoxia, tumor cells produce a secretion that modulates their microenvironment to facilitate tumor angiogenesis and metastasis. Here, we observed that hypoxic or reoxygenated A431 carcinoma cells exhibited enhanced angiogenic and metastatic potential such as reduced cellcell and cell-extracellular matrix adhesion, increased invasiveness, and production of a secretion with increased chorioallantoic membrane angiogenic activity. Consistent with these observations, quantitative proteomics revealed that under hypoxia the tumor cells secreted proteins involved in angiogenesis, focal adhesion, extracellular matrix-receptor interaction, and immune cell recruitment. Unexpectedly, the secreted proteins were predominantly cytoplasmic and membrane proteins. Ultracentrifugation at 100,000 ؋ g precipitated 54% of the secreted proteins and enriched for many exosome-associated proteins such as the tetraspanins and Alix and also proteins with the potential to facilitate angiogenesis and metastasis. Two tetraspanins, CD9 and CD81, co-immunoprecipitated. Together, these data suggested that tumor cells secrete proteins and exosomes with the potential to modulate their microenvironment and facilitate angiogenesis and metastasis. Molecular & Cellular Proteomics 9:1085-1099, 2010.

No abstract

Although Bacillus Calmette-Guérin (BCG) vaccines against tuberculosis have been available for more than 90 years, their effectiveness has been hindered by variable protective efficacy and a lack of lasting memory responses. One factor contributing to this variability may be the diversity of the BCG strains that are used around the world, in part from genomic changes accumulated during vaccine production and their resulting differences in gene expression. We have compared the genomes and transcriptomes of a global collection of fourteen of the most widely used BCG strains at single base-pair resolution. We have also used quantitative proteomics to identify key differences in expression of proteins across five representative BCG strains of the four tandem duplication (DU) groups. We provide a comprehensive map of single nucleotide polymorphisms (SNPs), copy number variation and insertions and deletions (indels) across fourteen BCG strains. Genome-wide SNP characterization allowed the construction of a new and robust phylogenic genealogy of BCG strains. Transcriptional and proteomic profiling revealed a metabolic remodeling in BCG strains that may be reflected by altered immunogenicity and possibly vaccine efficacy. Together, these integrated-omic data represent the most comprehensive catalogue of genetic variation across a global collection of BCG strains.

Human blood monocytes can be broadly divided into two distinct subsets: CD14+CD16- and CD14+/lowCD16+ subsets. Perturbation in their proportions in the blood has been observed in several disease conditions. Although numerous phenotypic and functional differences between the two subsets have already been described, the roles contributed by each subset during homeostasis or disease conditions are still largely unclear. To uncover novel differences to aid in elucidating their functions, we perform a global analysis of the two subsets utilizing both proteomics and transcriptomics approaches. From the proteomics and transcriptomics data, the expression of 613 genes by the two subsets is detected at both the protein and mRNA levels. These 613 genes are assessed for up-regulation in each subset at the protein and mRNA levels using a cutoff fold change of > or =|1.5| between subsets. Proteins and mRNAs up-regulated in each subset are then mapped in silico into biological functions. This mapping reveals copious functional differences between the subsets, many of which are seen at both protein and mRNA levels. For instance, expression of genes involved in F(CY) receptor-mediated phagocytosis are up-regulated in the CD14+/lowCD16+ subset, while those involved in antimicrobial function are up-regulated in the CD14+CD16- subset. We uncover novel functional differences between the monocyte subsets from differences in gene expression at the protein and mRNA levels. These functional differences would provide new insights into the different roles of the two monocyte subsets in regulating innate and adaptive immune responses.