title: Expression and promoter methylation analysis of ATP-binding cassette             genes in pancreatic cancer.
abstract: We investigated the relationship of ABCB1/MDR1, ABCC1/MRP1 and ABCG2/BCRP             expression and promoter methylation with pancreatic cancer tumorigenesis and drug             resistance. Gemcitabine-resistant pancreatic cancer cells, SW1990/GZ (33.3-fold             increased resistance), were obtained by treating SW1990 cells with gemcitabine.             The expression of ABCB1/MDR1, ABCC1/MRP1 and ABCG2/BCRP was determined by quantitative             real-time RT-PCR in the cell lines, 3 normal pancreatic tissues, 15 human pancreatic             cancer samples and 15 adjacent tissues. Promoter methylation was determined in             cell lines by bisulfite genomic sequencing. ABCB1/MDR1, ABCC1/MRP1 and ABCG2/BCRP             were upregulated in SW1990 and SW1990/GZ compared with normal pancreatic tissue,             and expression in SW1990/GZ was significantly higher than in SW1990 cells. ABCB1/MDR1,             ABCC1/MRP1 and ABCG2/BCRP were upregulated in pancreatic cancer tissues, compared             to adjacent tissues. The ABCB1/MDR1, ABCC1/MRP1 and ABCG2/BCRP promoter were hypomethylated             in all the cell lines. ABCB1/MDR1, ABCC1/MRP1 and ABCG2/BCRP expression correlated             with pancreatic cancer tumorigenesis and drug resistance in a mechanism that is             independent of promoter methylation.
authors.affiliation: Laboratory of General Surgery, Department of Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, PR China.
authors.forename: Minyong
authors.initials: M
authors.lastname: Chen
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Xue
authors.forename: Feitong
authors.initials: F
authors.lastname: Wang
authors.forename: Yong
authors.initials: Y
authors.lastname: An
authors.forename: Dong
authors.initials: D
authors.lastname: Tang
authors.forename: Yue
authors.initials: Y
authors.lastname: Xu
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.forename: Zhongxu
authors.initials: Z
authors.lastname: Yuan
authors.forename: Wentao
authors.initials: W
authors.lastname: Gao
authors.forename: Jishu
authors.initials: J
authors.lastname: Wei
authors.forename: Jingjing
authors.initials: J
authors.lastname: Zhang
authors.forename: Yi
authors.initials: Y
authors.lastname: Miao
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics*; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000235:genetics*; D019175:DNA Methylation; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D020869:Gene Expression Profiling; D006801:Humans; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics*; D009363:Neoplasm Proteins / Q000235:genetics*; D010190:Pancreatic Neoplasms / Q000235:genetics*; D011401:Promoter Regions, Genetic; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015854:Up-Regulation
chemical_list: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D009363:Neoplasm Proteins; C513055:ABCB1 protein, human; C116614:ABCG2 protein, human; C421109:multidrug resistance-associated protein 1