title: Identification of low abundance proteins in colorectal cancer tissues.
abstract: BACKGROUND
  Detection of low abundance proteins always possesses challenges even with the currently available proteomics technologies.
  
  
  OBJECTIVE
  We aimed to evaluate the low abundance differentially expressed proteins in colorectal cancerous tissues as compared to colorectal normal tissues.
  
  
  METHODS
  Protein separation was carried out by using the coupling methods of hydroxyapatite chromatography and SDS-PAGE followed by mass spectrometry analysis.
  
  
  RESULTS
  Five of the membrane associated low abundance proteins, namely uncharacterized protein C5orf4, coiled-coil domain containing protein 152, DnaJ homolog subfamily C member 22, tumor suppressor candidate 3 and leucine-rich repeat transmembrane neuronal protein 4 that previously only reported at the genome level were identified.
  
  
  CONCLUSIONS
  The proteins were isolated from the cancerous tissues as either up-regulated or down-regulated proteins as compared to normal tissues and therefore may play important roles in cancer development.
authors.affiliation: School of Pharmaceutical Sciences, University Sains Malaysia, and Surgery Department, Penang General Hospital, Penang, Malaysia.
authors.forename: Shi Rou
authors.initials: SR
authors.lastname: Lim
authors.forename: Boon-Hui
authors.initials: BH
authors.lastname: Gooi
authors.forename: Lay Harn
authors.initials: LH
authors.lastname: Gam
mesh_terms: D000595:Amino Acid Sequence; D014408:Biomarkers, Tumor / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D002852:Chromatography, Ion Exchange; D003106:Colon / Q000378:metabolism; D015179:Colorectal Neoplasms / Q000378:metabolism*; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D007526:Isoelectric Point; D008565:Membrane Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D008969:Molecular Sequence Data; D020543:Proteome / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D012007:Rectum / Q000378:metabolism; D053719:Tandem Mass Spectrometry
chemical_list: D014408:Biomarkers, Tumor; D008565:Membrane Proteins; D020543:Proteome