Cell-free DNA and RNA in plasma as a new molecular marker for prostate and breast cancer.
In this study, we examined several molecular markers in prostate and breast cancer patients and in normal individuals. The markers tested were: variations in the quantity of plasma DNA, glutathione-S-transferase P1 gene (GSTP1), Ras association domain family 1A (RASSF1A), and ataxia telangiectasia mutated (ATM) methylation status in plasma, carcinoembryonic antigen (CEA) and prostate-specific membrane antigen (PSMA) mRNA in peripheral blood mononuclear cells (PBMC) and plasma samples from prostate cancer patients. DNA quantification in plasma was performed using real-time PCR (RT-PCR). We assessed the methylation status of GSTP1 in plasma DNA using methylation-specific PCR (MSP) assay, while the methylation status of RASSF1A and ATM genes was examined by the MethyLight technology. RT-PCR analysis was used for the detection of mRNA, PSMA, and CEA. In 58.3% of newly diagnosed prostate cancer patients and 26.7% of prostate cancer patients under therapy, plasma DNA levels were increased. Additionally, 48.5% of breast cancer patients showed plasma DNA levels above the cutoff limit. GSTP1 Promotor hypermethylation was detectable in 75% of plasma samples obtained from patients with newly diagnosed prostate cancer and in 36.8% of patients under therapy, whereas 26% and 14% of the breast cancer patients tested were positive for RASSF1A and ATM methylation, respectively. The combination of DNA load and promotor methylation status identified 88% of prostate cancer patients and 54% of breast cancer patients. This study shows that free-circulating DNA can be detected in cancer patients compared with disease-free individuals, and suggests a new, noninvasive approach for early detection of cancer.
Papadopoulou
Eirini
E
Molecular Biology Research Center HYGEIA Antonis Papayiannis, Kifissias Ave. and Erythrou Stavrou 4 Str., 15123 Maroussi, Athens, Greece.
Davilas
Elias
E
Sotiriou
Vasilios
V
Georgakopoulos
Eleftherios
E
Georgakopoulou
Stavroula
S
Koliopanos
Alexander
A
Aggelakis
Filipos
F
Dardoufas
Konstantinos
K
Agnanti
Niki J
NJ
Karydas
Irini
I
Nasioulas
Georgios
G
D000954:Antigens, Surface / Q000097:blood / Q000235:genetics; D064007:Ataxia Telangiectasia Mutated Proteins; D014408:Biomarkers, Tumor; D001943:Breast Neoplasms / Q000097:blood / Q000175:diagnosis / Q000235:genetics; D002272:Carcinoembryonic Antigen / Q000097:blood / Q000235:genetics; D018797:Cell Cycle Proteins / Q000097:blood / Q000235:genetics; D004247:DNA / Q000097:blood*; D019175:DNA Methylation; D004268:DNA-Binding Proteins / Q000097:blood / Q000235:genetics; D005260:Female; D005819:Genetic Markers; D043425:Glutamate Carboxypeptidase II / Q000097:blood / Q000235:genetics; D051549:Glutathione S-Transferase pi / Q000097:blood / Q000235:genetics; D006801:Humans; D008297:Male; D010949:Plasma / Q000737:chemistry*; D011401:Promoter Regions, Genetic; D011471:Prostatic Neoplasms / Q000097:blood / Q000175:diagnosis / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000097:blood / Q000235:genetics; D012313:RNA / Q000097:blood*; D025521:Tumor Suppressor Proteins / Q000097:blood / Q000235:genetics
D000954:Antigens, Surface; D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D005819:Genetic Markers; C411762:RASSF1 protein, human; D025521:Tumor Suppressor Proteins; D012313:RNA; D004247:DNA; C496556:GSTP1 protein, human; D051549:Glutathione S-Transferase pi; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; D017346:Protein Serine-Threonine Kinases; C473848:FOLH1 protein, human; D043425:Glutamate Carboxypeptidase II