title: CIAPIN1 confers multidrug resistance by upregulating the expression of MDR-1 and MRP-1 in gastric cancer cells.
abstract: In a previous study, we observed that cytokine-induced apoptosis inhibitor 1 (CIAPIN1), a newly identified apoptosis inhibitor, was upregulated at the mRNA level in a multidrug-resistant gastric cancer cell line SGC7901/VCR. The aim of this study was to explore the role of CIAPIN1 in the development of multidrug resistance (MDR) in gastric cancer cells. Upregulation of CIAPIN1 in MDR gastric cancer cells was confirmed by semiquantitative RT-PCR and Western blotting. Using cDNA transfection and RNA interference, we successfully established stable transfectants with upregulation (i.e., SGC7901-pCIAPIN1) or downregulation (i.e., SGC7901-pSiCIAPIN1 and SGC7901/ADR-pSiCIAPIN1) of CIAPIN1 expression, respectively. In vitro drug sensitivity assay demonstrated that overexpression of CIAPIN1 conferred MDR in SGC7901 cells whereas downregulation of CIAPIN1 sensitized SGC7901 and SGC7901/ADR cells to anticancer drugs. CIAPIN1 protected both SGC7901 and SGC7901/ADR cells from ADR-induced apoptosis and reduced intracellular accumulation and retention of adriamycin. Moreover, expression of P-glycoprotein (P-gp or MDR-1, a product of MDR-1 gene) and MDR-related protein-1 (MRP-1) was upregulated by CIAPIN1. In addition, Western blotting revealed that CIAPIN1 decreased the expression of Bcl-2, Bax and p53. Therefore, it is concluded that CIAPIN1 confers MDR in gastric cancer cells, likely by upregulating MDR-1 and MRP-1.
authors.affiliation: State Key Laboratory of Cancer Biology, Institute of Digestive Diseases, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi Province, China.
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Hao
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Li
authors.forename: Taidong
authors.initials: T
authors.lastname: Qiao
authors.forename: Rui
authors.initials: R
authors.lastname: Du
authors.forename: Liu
authors.initials: L
authors.lastname: Hong
authors.forename: Daiming
authors.initials: D
authors.lastname: Fan
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics / Q000378:metabolism; D000230:Adenocarcinoma / Q000188:drug therapy / Q000378:metabolism*; D000970:Antineoplastic Agents / Q000378:metabolism; D017209:Apoptosis; D015153:Blotting, Western; D045744:Cell Line, Tumor; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D019450:Genes, MDR; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000502:physiology*; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics* / Q000378:metabolism; D013274:Stomach Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000503:physiopathology*; D014162:Transfection; D015854:Up-Regulation
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents; D047908:Intracellular Signaling Peptides and Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; C489114:CIAPIN1 protein, human; C421109:multidrug resistance-associated protein 1