title: Identification of plasma complement C3 as a potential biomarker for neuroblastoma using a quantitative proteomic approach.
abstract: The majority of patients diagnosed with neuroblastoma present with aggressive disease. Improved detection of neuroblastoma cancer cells following initial therapy may help in stratifying patient outcome and monitoring for relapse. To identify potential plasma biomarkers, we utilised a liquid chromatography-tandem mass spectrometry-based proteomics approach to detect differentially-expressed proteins in serum from TH-MYCN mice. TH-MYCN mice carry multiple copies of the human MYCN oncogene in the germline and homozygous mice for the transgene develop neuroblastoma in a manner resembling the human disease. The abundance of plasma proteins was measured over the course of disease initiation and progression. A list of 86 candidate plasma biomarkers was generated. Pathway analysis identified significant association of these proteins with genes involved in the complement system. One candidate, complement C3 protein, was significantly enriched in the plasma of TH-MYCN(+/+) mice at both 4 and 6weeks of age, and was found to be elevated in a cohort of human neuroblastoma plasma samples, compared to healthy subjects. In conclusion, we have demonstrated the suitability of the TH-MYCN(+/+) mouse model of neuroblastoma for identification of novel disease biomarkers in humans, and have identified Complement C3 as a candidate plasma biomarker for measuring disease state in neuroblastoma patients.
  
  
  CONCLUSIONS
  This study has utilised a unique murine model which develops neuroblastoma tumours that are biologically indistinguishable from human neuroblastoma. This animal model has effectively allowed the identification of plasma proteins which may serve as potential biomarkers of neuroblastoma. Furthermore, the label-free ion count quantitation technique which was used displays significant benefits as it is less labour intensive, feasible and accurate. We have been able to successfully validate this approach by confirming the differential abundance of two different plasma proteins. In addition, we have been able to confirm that the candidate biomarker Complement C3, is more abundant in the plasma of human neuroblastoma patient plasma samples when compared to healthy counterparts. Overall we have demonstrated that this approach can be potentially useful in the identification of biomarker candidates, and that further validation of the candidates may lead to the discovery of novel, clinically useful diagnostic tools in the detection of sub-clinical neuroblastoma.
authors.affiliation: Children's Cancer Institute Australia for Medical Research, Randwick, NSW 2031, Australia.
authors.forename: Patrick Y
authors.initials: PY
authors.lastname: Kim
authors.affiliation: Children's Cancer Institute Australia for Medical Research, Randwick, NSW 2031, Australia.
authors.forename: Owen
authors.initials: O
authors.lastname: Tan
authors.affiliation: Children's Cancer Institute Australia for Medical Research, Randwick, NSW 2031, Australia.
authors.forename: Sonya M
authors.initials: SM
authors.lastname: Diakiw
authors.affiliation: Children's Cancer Institute Australia for Medical Research, Randwick, NSW 2031, Australia.
authors.forename: Daniel
authors.initials: D
authors.lastname: Carter
authors.affiliation: Children's Cancer Institute Australia for Medical Research, Randwick, NSW 2031, Australia.
authors.forename: Eric O
authors.initials: EO
authors.lastname: Sekerye
authors.affiliation: Bioanalytical Mass Spectrometry Facility, Mark Wainwright Analytical Centre, University of New South Wales, Sydney, NSW, Australia.
authors.forename: Valerie C
authors.initials: VC
authors.lastname: Wasinger
authors.affiliation: Children's Cancer Institute Australia for Medical Research, Randwick, NSW 2031, Australia.
authors.forename: Tao
authors.initials: T
authors.lastname: Liu
authors.affiliation: Children's Cancer Institute Australia for Medical Research, Randwick, NSW 2031, Australia.
authors.forename: Maria
authors.initials: M
authors.lastname: Kavallaris
authors.affiliation: Children's Cancer Institute Australia for Medical Research, Randwick, NSW 2031, Australia.
authors.forename: Murray D
authors.initials: MD
authors.lastname: Norris
authors.affiliation: Children's Cancer Institute Australia for Medical Research, Randwick, NSW 2031, Australia.
authors.forename: Michelle
authors.initials: M
authors.lastname: Haber
authors.affiliation: Division of Cancer Biology, Institute for Cancer Research, Sutton, Surrey, UK.
authors.forename: Lou
authors.initials: L
authors.lastname: Chesler
authors.affiliation: Children's Cancer Institute Australia for Medical Research, Randwick, NSW 2031, Australia.
authors.forename: Alla
authors.initials: A
authors.lastname: Dolnikov
authors.affiliation: Children's Cancer Institute Australia for Medical Research, Randwick, NSW 2031, Australia; Kids Cancer Centre, Sydney Children's Hospital, Randwick, NSW 2031, Australia.
authors.forename: Toby N
authors.initials: TN
authors.lastname: Trahair
authors.affiliation: Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY, United States.
authors.forename: Nai-Kong
authors.initials: NK
authors.lastname: Cheung
authors.affiliation: Children's Cancer Institute Australia for Medical Research, Randwick, NSW 2031, Australia; Kids Cancer Centre, Sydney Children's Hospital, Randwick, NSW 2031, Australia. Electronic address: g.marshall@unsw.edu.au.
authors.forename: Glenn M
authors.initials: GM
authors.lastname: Marshall
authors.affiliation: Children's Cancer Institute Australia for Medical Research, Randwick, NSW 2031, Australia. Electronic address: bcheung@ccia.unsw.edu.au.
authors.forename: Belamy B
authors.initials: BB
authors.lastname: Cheung
mesh_terms: D000328:Adult; D000818:Animals; D015415:Biomarkers / Q000097:blood*; D002675:Child, Preschool; D003176:Complement C3 / Q000378:metabolism*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D009374:Neoplasms, Experimental / Q000097:blood*; D009447:Neuroblastoma / Q000097:blood*
chemical_list: D015415:Biomarkers; D003176:Complement C3
keywords: Biomarker; Complement C3; Complement system; Neuroblastoma; TH-MYCN(+/+); Zinc-alpha2-glycoprotein