Diagnostic values of GHSR DNA methylation pattern in breast cancer.
DNA methylation patterns have been recognised as cancer-specific markers with high potential for clinical applications. We aimed at identifying methylation variations that differentiate between breast cancers and other breast tissue entities to establish a signature for diagnosis. Candidate genomic loci were analysed in 117 fresh-frozen breast specimens, which included cancer, benign and normal breast tissues from patients as well as material from healthy individuals. A cancer-specific DNA methylation signature was identified by microarray analysis in a test set of samples (n = 52, p < 2.1 × 10(-4)) and its performance was assessed through bisulphite pyrosequencing in an independent validation set (n = 65, p < 1.9 × 10(-7)). The signature is associated with SFRP2 and GHSR genes, and exhibited significant hypermethylation in cancers. Normal-appearing breast tissues from cancer patients were also methylated at these loci but to a markedly lower extent. This occurrence of methylated DNA in normal breast tissue of cancer patients is indicative of an epigenetic field defect. Concerning diagnosis, receiver operating characteristic curves and the corresponding area under the curve (AUC) analysis demonstrated a very high sensitivity and specificity of 89.3 and 100 %, respectively, for the GHSR methylation pattern (AUC >0.99). To date, this represents the DNA methylation marker of the highest sensitivity and specificity for breast cancer diagnosis. Functionally, ectopic expression of GHSR in a cell line model reduced breast cancer cell invasion without affecting cell viability upon stimulation of cells with ghrelin. Our data suggest a link between epigenetic down-regulation of GHSR and breast cancer cell invasion.
Division of Functional Genome Analysis, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 580, 69120 Heidelberg, Germany.
Sandeep Kumar
SK
Botla
Amin Moghaddas
AM
Gholami
Mahdi
M
Malekpour
Evgeny A
EA
Moskalev
Mahdi
M
Fallah
Pouria
P
Jandaghi
Ali
A
Aghajani
Irina S
IS
Bondar
Ramesh
R
Omranipour
Fatemeh
F
Malekpour
Abbas
A
Mohajeri
Azin Jahangiri
AJ
Babadi
Özgür
Ö
Sahin
Vladimir V
VV
Bubnov
Hossein
H
Najmabadi
Jörg D
JD
Hoheisel
Yasser
Y
Riazalhosseini
D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000235:genetics* / Q000473:pathology; D045744:Cell Line, Tumor; D018899:CpG Islands; D019175:DNA Methylation; D015536:Down-Regulation; D044127:Epigenesis, Genetic; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics; D046228:Microarray Analysis; D011237:Predictive Value of Tests; D012372:ROC Curve; D054440:Receptors, Ghrelin / Q000235:genetics* / Q000378:metabolism; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D000094742:Secreted Frizzled-Related Proteins
D014408:Biomarkers, Tumor; D008565:Membrane Proteins; D054440:Receptors, Ghrelin; C109618:SFRP2 protein, human; D000094742:Secreted Frizzled-Related Proteins