title: Prognostic role of APC and RASSF1A promoter methylation status in cell free circulating DNA of operable gastric cancer patients.
abstract: Gastric carcinogenesis is a multistep process including not only genetic mutations but also epigenetic alterations. The best known and more frequent epigenetic alteration is DNA methylation affecting tumor suppressor genes that may be involved in various carcinogenetic pathways. The aim of the present study was to investigate the methylation status of APC promoter 1A and RASSF1A promoter in cell free DNA of operable gastric cancer patients. Using methylation specific PCR, we examined the methylation status of APC promoter 1A and RASSF1A promoter in 73 blood samples obtained from patients with gastric cancer. APC and RASSF1A promoters were found to be methylated in 61 (83.6%) and 50 (68.5%) of the 73 gastric cancer samples examined, but in none of the healthy control samples (p < 0.001). A significant association between methylated RASSF1A promoter status and lymph node positivity was observed (p = 0.005). Additionally, a significant correlation between a methylated APC promoter and elevated CEA (p = 0.033) as well as CA-19.9 (p = 0.032) levels, was noticed. The Kaplan-Meier estimates of survival, significantly favored patients with a non-methylated APC promoter status (p = 0.008). No other significant correlations between APC and RASSF1A methylation status and different tumor variables examined was observed. Serum RASSF1A and APC promoter hypermethylation is a frequent epigenetic event in patients with early operable gastric cancer. The observed correlations between APC promoter methylation status and survival as well as between a hypermethylated RASSF1A promoter and nodal positivity may be indicative of a prognostic role for those genes in early operable gastric cancer. Additional studies, in a larger cohort of patients are required to further explore whether these findings could serve as potential molecular biomarkers of survival and/or response to specific treatments.
authors.affiliation: Department of Medical Oncology, Medical School, Democritus University of Thrace, Greece. Electronic address: ioannabio@yahoo.it.
authors.forename: I
authors.initials: I
authors.lastname: Balgkouranidou
authors.affiliation: Department of Medical Oncology, Medical School, Democritus University of Thrace, Greece.
authors.forename: D
authors.initials: D
authors.lastname: Matthaios
authors.affiliation: Second Department of Surgery, Medical School, Democritus University of Thrace, Greece.
authors.forename: A
authors.initials: A
authors.lastname: Karayiannakis
authors.affiliation: Second Department of Surgery, Medical School, Democritus University of Thrace, Greece.
authors.forename: H
authors.initials: H
authors.lastname: Bolanaki
authors.affiliation: Department of Medical Oncology, Medical School, Democritus University of Thrace, Greece.
authors.forename: P
authors.initials: P
authors.lastname: Michailidis
authors.affiliation: Department of Medical Oncology, Medical School, Democritus University of Thrace, Greece.
authors.forename: N
authors.initials: N
authors.lastname: Xenidis
authors.affiliation: Department of Medical Oncology, Medical School, Democritus University of Thrace, Greece.
authors.forename: K
authors.initials: K
authors.lastname: Amarantidis
authors.affiliation: Department of Medical Oncology, Medical School, Democritus University of Thrace, Greece.
authors.forename: L
authors.initials: L
authors.lastname: Chelis
authors.affiliation: Laboratory of Statistics, Medical School, Democritus University of Thrace, Greece.
authors.forename: G
authors.initials: G
authors.lastname: Trypsianis
authors.affiliation: Department of Pharmacology, Medical School, Democritus University of Thrace, Greece.
authors.forename: E
authors.initials: E
authors.lastname: Chatzaki
authors.affiliation: Laboratory of Analytical Chemistry, Department of Chemistry, University of Athens, Greece.
authors.forename: E S
authors.initials: ES
authors.lastname: Lianidou
authors.affiliation: Department of Medical Oncology, Medical School, Democritus University of Thrace, Greece.
authors.forename: S
authors.initials: S
authors.lastname: Kakolyris
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood; D018395:CA-19-9 Antigen / Q000097:blood; D002272:Carcinoembryonic Antigen / Q000032:analysis; D002277:Carcinoma / Q000097:blood / Q000235:genetics* / Q000401:mortality / Q000556:secondary / Q000601:surgery; D019175:DNA Methylation; D004273:DNA, Neoplasm / Q000097:blood / Q000235:genetics*; D005260:Female; D017491:Genes, APC; D006801:Humans; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D011401:Promoter Regions, Genetic; D016016:Proportional Hazards Models; D013274:Stomach Neoplasms / Q000097:blood / Q000235:genetics* / Q000401:mortality / Q000601:surgery; D025521:Tumor Suppressor Proteins / Q000235:genetics*
chemical_list: D014408:Biomarkers, Tumor; D018395:CA-19-9 Antigen; D002272:Carcinoembryonic Antigen; D004273:DNA, Neoplasm; C411762:RASSF1 protein, human; D025521:Tumor Suppressor Proteins
keywords: APC; Cell free DNA; DNA methylation; Gastric cancer; Prognosis; RASSF1A