title: Co-suppression of MDR1 (multidrug resistance 1) and GCS (glucosylceramide synthase) restores sensitivity to multidrug resistance breast cancer cells by RNA interference (RNAi).
abstract: Multidrug resistance (MDR) to chemotherapeutic agents is a major obstacle to successful treatment in patients with breast cancer. Besides overexpression of MDR1, the member of the ABC transporter family, glucosylceramide synthase (GCS) which allows cellular escape from ceramide-induced cellular apoptosis by mediating ceramide glycosylation was considered to be related with multidrug resistance (MDR) in breast cancer. To specifically and efficiently reverse MDR of breast carcinoma cells, two small interference RNA (siRNA) targeted multidrug resistance 1 (MDR1) and GCS mediated by plasmids were constructed and co-transfected into the MDR breast cancer cell line MCF-7/ADM. The results showed that both transient transfection and stable transfection of the two siRNA-expression plasmids could greatly decrease the relative expression of GCS mRNA and MDR1 mRNA, significantly lower than the controls (p < 0.01). Evaluation of chemosensitivity displayed a 96-fold reduction in drug resistance for Adriamycin. And the reversing effects could keep for a long period (at least 3 w). Our results demonstrated that co-inhibition of MDR1 and GCS could more effectively reverse MDR in drug resistant breast carcinoma cells in vitro.
authors.affiliation: Department of Pathology, Qilu Hospital, Institute of Pathology and Pathophysiology, Shandong University of Medicine, Jinan, Shandong, China.
authors.forename: Xiaofang
authors.initials: X
authors.lastname: Zhang
authors.forename: Juan
authors.initials: J
authors.lastname: Li
authors.forename: Zhengang
authors.initials: Z
authors.lastname: Qiu
authors.forename: Peng
authors.initials: P
authors.lastname: Gao
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Wu
authors.forename: Genyin
authors.initials: G
authors.lastname: Zhou
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000235:genetics* / Q000378:metabolism; D045744:Cell Line, Tumor; D015536:Down-Regulation; D004317:Doxorubicin / Q000494:pharmacology; D018432:Drug Resistance, Multiple; D004354:Drug Screening Assays, Antitumor; D005260:Female; D020868:Gene Silencing; D005964:Glucosyltransferases / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000096:biosynthesis / Q000235:genetics; D006801:Humans; D034622:RNA Interference; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D034741:RNA, Small Interfering / Q000008:administration & dosage / Q000235:genetics; D014162:Transfection
chemical_list: C513055:ABCB1 protein, human; D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000903:Antibiotics, Antineoplastic; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D004317:Doxorubicin; D005964:Glucosyltransferases; C023246:ceramide glucosyltransferase