[2014 Spring Life Sciences & IBB Regular Seminar]
   
     
▶Subject: Functional and quantitative proteomic analysis of two distinct populations of extracellular vesicles from the same cell source
         
  
▶Speaker: Prof. Dolores Di Vizio (Harvard Medical School &  Cedars?Sinai Medical Center)
           

▶Date: 4:00PM/June/24(Tue)/2014
          
    
▶Place: Auditorium(1F), Postech Biotech Center
           
       *Abctract
       We recently discovered that rapidly migratory, “amoeboid” prostate cancer cells shed large (1-10μm diameter), bioactive extracellular vesicles (EVs), termed large oncosomes. Large oncosomes can be selectively isolated by differential centrifugation and/or by filtration, and analyzed by immunoflow cytometry with specific size beads in vitro and in vivo. Their quantitation in the circulation reports metastatic disease in patients and animal models (Cancer Res. 2009; Am J Pathol. 2012). In order to profile large oncosomes at a molecular level, we performed next generation sequencing (whole genome and RNA-seq) and quantitative proteomics studies (LC-MS/MS SILAC). We demonstrated the feasibility of RNA-seq analysis of EVs purified from human platelet-poor plasma and have obtained a minimum of 50 million paired end reads per sample. After mapping to RefSeqannotated human gene loci and quantification as FPKM (fragments per kilobase of exon per million fragments mapped), a number of transcripts were identified as differentially expressed between patients with breast cancer and normal subjects (FDR <0.05). We also performed whole genome paired-end sequencing (Illumina) of large oncosome-derived DNA and demonstrated that single nucleotide mutations, insertions/deletions, and translocations present in donor cells can be identified in large oncosomes. Finally, SILAC profiling of tumor cell-derived large oncosomes in comparison with smaller EVs including exosomes demonstrated enrichment, in large oncosomes, of proteins functionally involved in cell cycle regulation, anti-apoptosis, and cell motility. Among the classes of proteins often identified in EVs, a cohort of these “exosome” biomarkers were significantly enriched in large oncosomes. These findings identify large oncosomes as a novel class of EV that contains clinically relevant biomarkers.

▶Inquiry: Prof.Gho, Yong Song (279-2345)
         
   
   * This seminar will be given in English