title: Identification of Apolipoprotein C-I Peptides as a Potential Biomarker and its Biological Roles in Breast Cancer.
abstract: BACKGROUND
  Breast cancer (BC) is one of the most common cancers and is among the main causes of death in females around the world. Although several serum biomarkers have been identified for breast cancer, due to lack of adequate sensitivity and specificity they do not adequately distinguish BC from confounding conditions. New approaches are urgently needed to improve BC detection and treatment.
  
  
  METHODS
  Eighty serum samples from 20 healthy individuals and 60 patients with BC (22 triple-negative breast cancer, TNBC; 38 non-triple-negative breast cancer, NTNBC) were included. Protein profiling of serum samples was analyzed using surface-enhanced laser desorption/ionization time-of-flight mass spectroscopy (SELDI-TOF-MS). Candidate biomarkers were purified by SDS-PAGE electrophoresis and identified by MALDI-TOF/TOF.
  
  
  RESULTS
  The candidate biomarker positioned at 6447.9 m/z was significantly decreased in BC patients. Moreover, the expression intensity of the candidate biomarker was weaker in the TNBC and pre-surgery group compared with the NTNBC and post-surgery group. We ultimately identified the biomarker as apolipoprotein C-I (ApoC-I). Furthermore, we found that ApoC-I peptides inhibited proliferation of human breast cancer cells in vitro and suppressed tumor growth in vivo.
  
  
  CONCLUSIONS
  These results suggest that ApoC-I peptides may be a potential diagnostic biomarker and therapeutic approach for BC.
authors.affiliation: Department of Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China (mainland).
authors.forename: Yadong
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Department of Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China (mainland).
authors.forename: Junjie
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China (mainland).
authors.forename: Fei
authors.initials: F
authors.lastname: Guo
authors.affiliation: Department of Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China (mainland).
authors.forename: Wei
authors.initials: W
authors.lastname: Zhao
authors.affiliation: Department of Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China (mainland).
authors.forename: Yuxiao
authors.initials: Y
authors.lastname: Zhan
authors.affiliation: Department of Breast, Henan Cancer Hospital, Affiliated Cancer Hospital of Zhengzhou University, Zhengzhou, Henan, China (mainland).
authors.forename: Chenyu
authors.initials: C
authors.lastname: Liu
authors.affiliation: Department of Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China (mainland).
authors.forename: Yuxia
authors.initials: Y
authors.lastname: Fan
authors.affiliation: Department of Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China (mainland).
authors.forename: Jiaxiang
authors.initials: J
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D000595:Amino Acid Sequence; D000818:Animals; D053302:Apolipoprotein C-I / Q000737:chemistry / Q000378:metabolism*; D017209:Apoptosis / Q000187:drug effects; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001798:Blood Proteins / Q000378:metabolism; D001943:Breast Neoplasms / Q000378:metabolism* / Q000601:surgery; D016022:Case-Control Studies; D049109:Cell Proliferation / Q000187:drug effects; D005260:Female; D006801:Humans; D061986:MCF-7 Cells; D008819:Mice, Nude; D008875:Middle Aged; D010455:Peptides / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D055815:Young Adult
chemical_list: D053302:Apolipoprotein C-I; D014408:Biomarkers, Tumor; D001798:Blood Proteins; D010455:Peptides