title: Altered methylation of glucosylceramide synthase promoter regulates its expression and associates with acquired multidrug resistance in invasive ductal breast cancer.
abstract: Overexpression of glucosylceramide synthase (GCS) increases multidrug resistance (MDR) in many cancer cells. However, its mechanism is unknown. The aim of the present study is to detect the association of methylation at the GCS gene promoter with its expression and MDR in invasive ductal breast cancer. 40 cases GCS-positive and 40 cases GCS-negative primary breast carcinoma samples, three drug-sensitive breast cancer cell lines and one multidrug-resistant breast cancer cell line were used. Immunohistochemistry, methylation-specific PCR (MSP), quantitative real-time (qPCR), westernblot and cytotoxicity assay techniques were employed. Thwe results revealed that there was a statistically negative correlation between GCS CpG islands methylation and GCSphenotype in patients with breast cancer. GCS CpG islands methylation was negatively associated with high ER, meanwhile positively with high HER-2 status. Similar results were obtained from the analysis of breast cancer cell lines. Treatment with the demethylating agent 5-aza-2'-deoxycytidine (5-Aza-dc) changed the GCS promoter methylation pattern in three sensitive cells and also caused increased drug resistance of them. These results suggested that the changes of DNA methylation status of the GCS promoter correlates with multidrug resistance in breast cancer.
authors.affiliation: Department of Oncology, Yuhuangding Hospital, Yantai, Shandong, 264000, P. R. China.
authors.forename: Jiannan
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Pathology, Shandong University School of Medicine, Jinan, Shandong, 250012, P. R. China.
authors.forename: Xiaofang
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Oncology, Yuhuangding Hospital, Yantai, Shandong, 264000, P. R. China.
authors.forename: Aina
authors.initials: A
authors.lastname: Liu
authors.affiliation: Department of Rehabilitation, Qianfoshan Hospital, Jinan, Shandong, 250014, P. R. China.
authors.forename: Daoping
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Department of Oncology, Yuhuangding Hospital, Yantai, Shandong, 264000, P. R. China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Su
authors.affiliation: Department of Oncology, Yuhuangding Hospital, Yantai, Shandong, 264000, P. R. China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Oncology, Yuhuangding Hospital, Yantai, Shandong, 264000, P. R. China.
authors.forename: Dong
authors.initials: D
authors.lastname: You
authors.affiliation: Department of Radiology, Taian Central Hospital, Taian, Shandong, 271000, P. R. China.
authors.forename: Leilei
authors.initials: L
authors.lastname: Yuan
authors.affiliation: Department of Oncology, Yuhuangding Hospital, Yantai, Shandong, 264000, P. R. China.
authors.forename: Xiangshuo
authors.initials: X
authors.lastname: Kong
authors.affiliation: Department of Oncology, Yuhuangding Hospital, Yantai, Shandong, 264000, P. R. China.
authors.forename: Xiaodan
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Oncology, Yuhuangding Hospital, Yantai, Shandong, 264000, P. R. China.
authors.forename: Ping
authors.initials: P
authors.lastname: Sun
mesh_terms: D000328:Adult; D001374:Azacitidine / Q000031:analogs & derivatives / Q000494:pharmacology; D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D018899:CpG Islands / Q000235:genetics; D019175:DNA Methylation / Q000187:drug effects / Q000235:genetics*; D000077209:Decitabine; D018432:Drug Resistance, Multiple / Q000235:genetics; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D005964:Glucosyltransferases / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D061986:MCF-7 Cells; D009361:Neoplasm Invasiveness; D011401:Promoter Regions, Genetic / Q000235:genetics*
chemical_list: D004791:Enzyme Inhibitors; D000077209:Decitabine; D005964:Glucosyltransferases; C023246:ceramide glucosyltransferase; D001374:Azacitidine
keywords: 5-Aza-dc; DNA methylation; breast cancer; glucosylceramide synthase