title: Downregulation of C3 and C4A/B complement factor fragments in plasma from patients with squamous cell carcinoma of the penis.
abstract: OBJECTIVE
  To investigate the use of ClinProt technique to identify cancer markers in plasma of patients suffering from squamous cell carcinoma of the penis (SCCP).
  
  
  METHODS
  Plasma of 36 healthy subjects and 25 patients with penile carcinoma who underwent surgical treatment between June 2010 and June 2011 was collected and analyzed by the ClinProt/MALDI/ToF technique. Then the peptides were identified from the C8 MB eluted fraction of patients' and control subjects' plasma by LIFT MS/MS.
  
  
  RESULTS
  A cluster of 2 peptides (A=m/z 1897.22 ± 9 Da and B=m/z 2021.99 ± 9 Da) was able to discriminate patients from control subjects. Cross validation analysis using the whole casuistic showed 62.5 % and 86.76 % sensitivity and specificity, respectively. The cluster also showed very high sensitivity (100 %) and specificity (97%) for SCCP patients that died due to the disease. Furthermore, patients with lymph node involvement presented sensitivity and specificity of 80 % and 97 %, respectively. These two peptides were identified by the proteomic approach based on a MALDI-TOF/TOF as fragments of C3 (m/z 1896.17) and C4a/b (m/z 2021.26) complement proteins.
  
  
  CONCLUSIONS
  The results showed that as the disease progresses, the fragments C3 and C4 A/B are less expressed in comparison with healthy subjects. These results may be useful as prognostic tools.
authors.affiliation: Laboratory of Applied Genetics, Hematology Service and Department of Urology, Brazilian National Cancer Institute, Praça da Cruz Vermelha 23, RJ, Brazil. ornellasa@hotmail.com
authors.forename: Paulo
authors.initials: P
authors.lastname: Ornellas
authors.forename: Antonio Augusto
authors.initials: AA
authors.lastname: Ornellas
authors.forename: Clizia
authors.initials: C
authors.lastname: Chinello
authors.forename: Erica
authors.initials: E
authors.lastname: Gianazza
authors.forename: Veronica
authors.initials: V
authors.lastname: Mainini
authors.forename: Marta
authors.initials: M
authors.lastname: Cazzaniga
authors.forename: Denise Abreu
authors.initials: DA
authors.lastname: Pereira
authors.forename: Vanessa
authors.initials: V
authors.lastname: Sandim
authors.forename: Ana Sheila
authors.initials: AS
authors.lastname: Cypriano
authors.forename: Leandro
authors.initials: L
authors.lastname: Koifman
authors.forename: Paulo Cesar Barbosa da
authors.initials: PC
authors.lastname: Silva
authors.forename: Gilda
authors.initials: G
authors.lastname: Alves
authors.forename: Fulvio
authors.initials: F
authors.lastname: Magni
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood; D002294:Carcinoma, Squamous Cell / Q000097:blood* / Q000276:immunology / Q000473:pathology; D003176:Complement C3 / Q000032:analysis*; D015934:Complement C4a / Q000032:analysis*; D015935:Complement C4b / Q000032:analysis*; D015536:Down-Regulation; D006801:Humans; D008297:Male; D008875:Middle Aged; D010412:Penile Neoplasms / Q000097:blood* / Q000276:immunology / Q000473:pathology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020539:Sequence Analysis, Protein; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D014408:Biomarkers, Tumor; D003176:Complement C3; D015934:Complement C4a; D015935:Complement C4b