TY  - JOUR
A1  - Hansmann, Tamara
A1  - Pliushch, Galyna
A1  - Leubner, Monika
A1  - Kroll, Patricia
A1  - Endt, Daniela
A1  - Gehrig, Andrea
A1  - Preisler-Adams, Sabine
A1  - Wieacker, Peter
A1  - Haaf, Thomas
T1  - Constitutive promoter methylation of BRCA1 and RAD51C in patients with familial ovarian cancer and early-onset sporadic breast cancer
JF  - Human Molecular Genetics
N2  - Genetic defects in breast cancer (BC) susceptibility genes, most importantly BRCA1 and BRCA2, account for ∼40% of hereditary BC and ovarian cancer (OC). Little is known about the contribution of constitutive (soma-wide) epimutations to the remaining cases. We developed bisulfite pyrosequencing assays to screen >600 affected BRCA1/BRCA2 mutation-negative patients from the German Consortium for Hereditary Breast and Ovarian Cancer for constitutive hypermethylation of ATM, BRCA1, BRCA2, RAD51C, PTEN and TP53 in blood cells. In a second step, patients with ≥6% promoter methylation were analyzed by bisulfite plasmid sequencing to demonstrate the presence of hypermethylated alleles (epimutations), indicative of epigenetic gene silencing. Altogether we identified nine (1.4%) patients with constitutive BRCA1 and three (0.5%) with RAD51C hypermethylation. Epimutations were found in both sporadic cases, in particular in 2 (5.5%) of 37 patients with early-onset BC, and familial cases, in particular 4 (10%) of 39 patients with OC. Hypermethylation was always confined to one of the two parental alleles in a subset (12–40%) of the analyzed cells. Because epimutations occurred in cell types from different embryonal layers, they most likely originated in single cells during early somatic development. We propose that analogous to germline genetic mutations constitutive epimutations may serve as the first hit of tumor development. Because the role of constitutive epimutations in cancer development is likely to be largely underestimated, future strategies for effective testing of susceptibility to BC and OC should include an epimutation screen.
KW  - promoter methylation
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-125673
VL  - 21
IS  - 21
ER  - 
TY  - JOUR
A1  - Litovkin, Kirill
A1  - Van Eynde, Aleyde
A1  - Joniau, Steven
A1  - Lerut, Evelyne
A1  - Laenen, Annouschka
A1  - Gevaert, Thomas
A1  - Gevaert, Olivier
A1  - Spahn, Martin
A1  - Kneitz, Burkhard
A1  - Gramme, Pierre
A1  - Helleputte, Thibault
A1  - Isebaert, Sofie
A1  - Haustermans, Karin
A1  - Bollen, Mathieu
T1  - DNA Methylation-Guided Prediction of Clinical Failure in High-Risk Prostate Cancer
JF  - PLoS ONE
N2  - Background 
Prostate cancer (PCa) is a very heterogeneous disease with respect to clinical outcome. This study explored differential DNA methylation in a priori selected genes to diagnose PCa and predict clinical failure (CF) in high-risk patients. 

Methods 
A quantitative multiplex, methylation-specific PCR assay was developed to assess promoter methylation of the APC, CCND2, GSTP1, PTGS2 and RARB genes in formalin-fixed, paraffin-embedded tissue samples from 42 patients with benign prostatic hyperplasia and radical prostatectomy specimens of patients with high-risk PCa, encompassing training and validation cohorts of 147 and 71 patients, respectively. Log-rank tests, univariate and multivariate Cox models were used to investigate the prognostic value of the DNA methylation. 

Results 
Hypermethylation of APC, CCND2, GSTP1, PTGS2 and RARB was highly cancer-specific. However, only GSTP1 methylation was significantly associated with CF in both independent high-risk PCa cohorts. Importantly, trichotomization into low, moderate and high GSTP1 methylation level subgroups was highly predictive for CF. Patients with either a low or high GSTP1 methylation level, as compared to the moderate methylation groups, were at a higher risk for CF in both the training (Hazard ratio [HR], 3.65; 95% CI, 1.65 to 8.07) and validation sets (HR, 4.27; 95% CI, 1.03 to 17.72) as well as in the combined cohort ( HR, 2.74; 95% CI, 1.42 to 5.27) in multivariate analysis. 

Conclusions 
Classification of primary high-risk tumors into three subtypes based on DNA methylation can be combined with clinico-pathological parameters for a more informative risk-stratification of these PCa patients.
KW  - CpG island hypermethylation
KW  - radical prostatectomy
KW  - promoter methylation
KW  - receptor beta
KW  - gene
KW  - GSTP1
KW  - biomarkers
KW  - diagnosis
KW  - recurrence
KW  - reveals
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-151705
VL  - 10
IS  - 6
ER  -