title: Promoter methylation profiles between human lung adenocarcinoma multidrug resistant A549/cisplatin (A549/DDP) cells and its progenitor A549 cells.
abstract: Although aberrant DNA methylation has been implicated in the pathophysiology of lung cancer, the role of methylation in multidrug resistance (MDR) of lung cancer has remained unclear. To investigate whether certain distinct DNA methylation pattern is associated with acquired MDR of lung adenocarcinoma, methylated-DNA immunoprecipitation-chromatin immunoprecipitation (MeDIP-ChIP) was utilised to compare the genome-wide promoter methylation of the human lung adenocarcinoma MDR A549/cisplatin (A549/DDP) cells with its progenitor A549 cells. The comparison identified 3617 genes with differentially methylated promoter, of which 1581 were hypermethylated and 2036 were hypomethylated. Then, bisulphite sequencing polymerase chain reaction (PCR) (BSP) and quantitative reverse transcription (RT)-PCR (Q-PCR) were used to validate the promoter methylation of five candidate genes and to determine whether the expression of genes was associated with the promoter methylation. BSP confirmed that the promoter methylation incidence of the hypermethylated genes, G protein-coupled receptor 56 isoform 3 (GPR56), metallothionein 1G (MT1G), and RAS association domain family gene 1 (RASSF1), was significantly higher in A549/DDP cells compared with A549 cells (p<0.001, p=0.0099, and p=0.0165), whereas no significant difference was found in that of the other two genes, CCNL2 and BAD (p=0.0594 and p=0.5546). Additionally, Q-PCR showed that the mRNA expression of the three hypermethylated genes was significantly lower in A549/DDP cells compared with A549 cells (all p<0.001). In conclusion, this study reported for the first time that a distinct promoter methylation pattern is associated with MDR of lung adenocarcinoma A549/DDP cells and suggested that GPR56, MT1G, and RASSF1 might be the potential methylation markers associated with acquired MDR of lung adenocarcinoma.
authors.affiliation: Department of Respiratory Diseases, 324th Hospital of the People's Liberation Army, Chongqing 400020, China. fairy780308@163.com
authors.forename: Ruiling
authors.initials: R
authors.lastname: Guo
authors.forename: Guoming
authors.initials: G
authors.lastname: Wu
authors.forename: Haidong
authors.initials: H
authors.lastname: Li
authors.forename: Pin
authors.initials: P
authors.lastname: Qian
authors.forename: Juan
authors.initials: J
authors.lastname: Han
authors.forename: Feng
authors.initials: F
authors.lastname: Pan
authors.forename: Wenbi
authors.initials: W
authors.lastname: Li
authors.forename: Jin
authors.initials: J
authors.lastname: Li
authors.forename: Fuyun
authors.initials: F
authors.lastname: Ji
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics*; D000077192:Adenocarcinoma of Lung; D045744:Cell Line, Tumor; D019175:DNA Methylation / Q000235:genetics*; D018432:Drug Resistance, Multiple / Q000235:genetics*; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D055106:Genome-Wide Association Study; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics*; D008668:Metallothionein / Q000235:genetics; D011401:Promoter Regions, Genetic; D043562:Receptors, G-Protein-Coupled / Q000235:genetics; D025521:Tumor Suppressor Proteins / Q000235:genetics
chemical_list: C118925:ADGRG1 protein, human; C499629:MT1G protein, human; C411762:RASSF1 protein, human; D043562:Receptors, G-Protein-Coupled; D025521:Tumor Suppressor Proteins; D008668:Metallothionein