title: Low dose of arsenic trioxide inhibits multidrug resistant-related P-glycoprotein expression in human neuroblastoma cell line.
abstract: This study investigated arsenic trioxide (As2O3), cisplatin (DDP) and etoposide (Vp16) on the anticancer effects and P-glycoprotein (P-gp) expression in neuroblastoma (NB) SK-N-SH cells. The potential influence of As2O3, DDP and Vp16 currently included in NB routine treatment protocols on cytotoxicity in SK-N-SH cells was measured by flow cytometry and drug half-maximal inhibitory concentration (IC50) was established. Moreover, chemotherapeutic agent-mediated changes of cellular expression levels of resistant-related P-gp, was monitored using western blotting. The data showed that As2O3, DDP and Vp16 significantly inhibited the growth and survival of the SK-N-SH cells at different concentration. Notably, the levels of apoptosis were upregulated in SK-N-SH cells with an acceleration of the exposure time and the concentration of As2O3, DDP and Vp16. As2O3, DDP and Vp16 were observed with their IC50 values on SK-N-SH cells being 3 µM, 8 and 100 µg/ml, respectively. Flow cytometry analysis showed that As2O3 at low concentrations in SK-N-SH cells led to enhanced accumulation of cell populations in G2/M phase with increasing the exposure time, and increased levels of apoptosis. In contrast, we observed that SK-N-SH cell populations arrested in S phase by DDP and Vp16. In vitro examination revealed that following pretreatment of SK-N-SH cells with As2O3, the expression of P-gp was not increased. The expression of P-gp downregulation were noted following the group treated by As2O3 at 2 and 3 µM. Exposed to As2O3 at 3 µM for 72 h, SK-N-SH cells exhibited lower expression of P-gp than 2 µM As2O3 for 72 h. In contrast, the expression of P-gp was upregulated by DDP and VP16. In summary, SK-N-SH cells were responsive to chemotherapeutic agent-induced apoptosis in a dose-dependent and time-dependent manner. In particular, ours findings showed that low dose of As2O3 markedly reduced the P-gp expression and increased apoptotic cell death in human NB cell line.
authors.affiliation: Department of Pediatric, Affiliated Hospital of Guangdong Medical University, Zhan Jiang, Guangdong 524000, P.R. China.
authors.forename: Ling
authors.initials: L
authors.lastname: Liu
authors.affiliation: Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong 510120, P.R. China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Li
authors.affiliation: Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong 510120, P.R. China.
authors.forename: Xilin
authors.initials: X
authors.lastname: Xiong
authors.affiliation: Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong 510120, P.R. China.
authors.forename: Kai
authors.initials: K
authors.lastname: Qi
authors.affiliation: Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong 510120, P.R. China.
authors.forename: Chi
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong 510120, P.R. China.
authors.forename: Jianpei
authors.initials: J
authors.lastname: Fang
authors.affiliation: Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong 510120, P.R. China.
authors.forename: Haixia
authors.initials: H
authors.lastname: Guo
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000096:biosynthesis*; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D000077237:Arsenic Trioxide; D001152:Arsenicals / Q000494:pharmacology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002945:Cisplatin / Q000494:pharmacology*; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D005047:Etoposide / Q000494:pharmacology*; D059565:G2 Phase Cell Cycle Checkpoints / Q000187:drug effects; D006801:Humans; D009447:Neuroblastoma / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology*; D010087:Oxides / Q000494:pharmacology*
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents; D001152:Arsenicals; D010087:Oxides; D005047:Etoposide; D002945:Cisplatin; D000077237:Arsenic Trioxide