title: Methylation of PITX2, HOXD3, RASSF1 and TDRD1 predicts biochemical recurrence in high-risk prostate cancer.
abstract: OBJECTIVE
  To explore differential methylation of HAAO, HOXD3, LGALS3, PITX2, RASSF1 and TDRD1 as a molecular tool to predict biochemical recurrence (BCR) in patients with high-risk prostate cancer (PCa).
  
  
  METHODS
  A multiplexed nested methylation-specific PCR was applied to quantify promoter methylation of the selected markers in five cell lines, 42 benign prostatic hyperplasia (BPH) and 71 high-risk PCa tumor samples. Uni- and multivariate Cox regression models were used to assess the importance of the methylation level in predicting BCR.
  
  
  RESULTS
  A PCa-specific methylation marker HAAO in combination with HOXD3 and a hypomethylation marker TDRD1 distinguished PCa samples (>90 % of tumor cells each) from BPH with a sensitivity of 0.99 and a specificity of 0.95. High methylation of PITX2, HOXD3 and RASSF1, as well as low methylation of TDRD1, appeared to be significantly associated with a higher risk for BCR (HR 3.96, 3.44, 2.80 and 2.85, correspondingly) after correcting for established risk factors. When DNA methylation was treated as a continuous variable, a two-gene model PITX2 × 0.020677 + HOXD3 × 0.0043132 proved to be the best predictor of BCR (HR 4.85) compared with the individual markers. This finding was confirmed in an independent set of 52 high-risk PCa tumor samples (HR 11.89).
  
  
  CONCLUSIONS
  Differential promoter methylation of HOXD3, PITX2, RASSF1 and TDRD1 emerges as an independent predictor of BCR in high-risk PCa patients. A two-gene continuous DNA methylation model "PITX2 × 0.020677 + HOXD3 × 0.0043132" is a better predictor of BCR compared with individual markers.
authors.affiliation: Laboratory of Biosignaling and Therapeutics, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium, k.litovkin@yahoo.com.
authors.forename: Kirill
authors.initials: K
authors.lastname: Litovkin
authors.forename: Steven
authors.initials: S
authors.lastname: Joniau
authors.forename: Evelyne
authors.initials: E
authors.lastname: Lerut
authors.forename: Annouschka
authors.initials: A
authors.lastname: Laenen
authors.forename: Olivier
authors.initials: O
authors.lastname: Gevaert
authors.forename: Martin
authors.initials: M
authors.lastname: Spahn
authors.forename: Burkhard
authors.initials: B
authors.lastname: Kneitz
authors.forename: Sofie
authors.initials: S
authors.lastname: Isebaert
authors.forename: Karin
authors.initials: K
authors.lastname: Haustermans
authors.forename: Monique
authors.initials: M
authors.lastname: Beullens
authors.forename: Aleyde
authors.initials: A
authors.lastname: Van Eynde
authors.forename: Mathieu
authors.initials: M
authors.lastname: Bollen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002352:Carrier Proteins / Q000235:genetics*; D018797:Cell Cycle Proteins; D045744:Cell Line, Tumor; D019175:DNA Methylation; D018398:Homeodomain Proteins / Q000235:genetics*; D006801:Humans; D007610:Kallikreins / Q000097:blood; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000097:blood / Q000235:genetics*; D011401:Promoter Regions, Genetic; D016016:Proportional Hazards Models; D017430:Prostate-Specific Antigen / Q000097:blood; D011470:Prostatic Hyperplasia / Q000235:genetics; D011471:Prostatic Neoplasms / Q000097:blood / Q000235:genetics / Q000473:pathology*; D014157:Transcription Factors / Q000235:genetics*; D025521:Tumor Suppressor Proteins / Q000235:genetics*; D000097577:Homeobox Protein PITX2
chemical_list: D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D018398:Homeodomain Proteins; D007610:Kallikreins; D017430:Prostate-Specific Antigen; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; D000097577:Homeobox Protein PITX2; C411762:RASSF1 protein, human; C580566:TDRD1 protein, human; C073547:HOXA4 protein, human; C549870:KLK3 protein, human