title: Is relative quantification dispensable for the measurement of microRNAs as serum biomarkers in germ cell tumors?
abstract: BACKGROUND
  Classical biomarkers α-fetoprotein, β-human chorionic gonadotropin and lactate dehydrogenase (AFP, bHCG and LDH) are elevated in only 60% of all testicular germ cell tumor (TGCT) patients. microRNAs (miRNAs) are a novel class of useful biomarkers in cancer and miRNAs of the miR-371-3 cluster were proven to be valuable markers for TGCT patients.
  
  
  METHODS
  We compared the Ct and ΔCt values of miR-371-3 by real time PCR (qPCR) with and without 18S rRNA for normalization. Expression of miR-371a-3p, miR-372 and miR-373-3p was measured in 25 TGCTs, 4 non-TGCTs and 17 age-matched male controls.
  
  
  RESULTS
  A highly positive correlation between Ct and ΔCt values was found in all samples. The highest correlation was found for miR-371a-3p (R2: 0.956).
  
  
  CONCLUSIONS
  RESULTS show that qPCR can be used without endogenous control for analyzing miR-371-3 in the serum of patients with testicular cancer and male controls if the technical procedure is performed under controlled conditions.
authors.affiliation: Center for Human Genetics, University of Bremen, Bremen, Germany.
authors.forename: Meike
authors.initials: M
authors.lastname: Spiekermann
authors.affiliation: Department of Urology, Albertinen-Hospital, Hamburg, Germany.
authors.forename: Klaus-Peter
authors.initials: KP
authors.lastname: Dieckmann
authors.affiliation: Department of Urology, Albertinen-Hospital, Hamburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Balks
authors.affiliation: Center for Human Genetics, University of Bremen, Bremen, Germany Institute for Medical Genetics, University of Rostock, University Medicine, Rostock, Germany.
authors.forename: Jörn
authors.initials: J
authors.lastname: Bullerdiek
authors.affiliation: Center for Human Genetics, University of Bremen, Bremen, Germany belge@uni-bremen.de.
authors.forename: Gazanfer
authors.initials: G
authors.lastname: Belge
mesh_terms: D000293:Adolescent; D000328:Adult; D014408:Biomarkers, Tumor / Q000097:blood* / Q000235:genetics; D016022:Case-Control Studies; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000097:blood* / Q000235:genetics; D008875:Middle Aged; D009373:Neoplasms, Germ Cell and Embryonal / Q000097:blood*; D060888:Real-Time Polymerase Chain Reaction; D013736:Testicular Neoplasms / Q000097:blood*; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; C554834:MIRN371 microRNA, human; D035683:MicroRNAs
keywords: Biomarker; endogenous control; germ cell tumors; microRNA; real time PCR; testicular cancer