title: RAD001 can reverse drug resistance of SGC7901/DDP cells.
abstract: To investigate the role of RAD001 in the reversing of drug resistance of SGC7901/DDP, we cultured SGC7901/DDP cells with different groups of drugs (RAD001, cisplatin (DDP) alone, or the combination of RAD001 and DDP); after that, we detected the drug sensitivity, cell apoptosis, and levels of P-gp, MRP1, and survivin in the cells of SGC7901/DDP by MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphe-nyltetrazolium bromide) assay, flow cytometry, immunohistochemical analysis, and Western blot analysis. There was no significant difference between DDP 2.5-mg/L group and negative control group. When the cells were pretreated with RAD001 2.5, 5 nmol/L, the proliferation of SGC7901/DDP cells was inhibited by DDP 2.5 mg/L significantly, compared to negative control group, DDP 2.5-mg/L group, and RAD001 2.5, 5-nmol/L group, respectively (P < 0.05); there were significant differences between combination groups (P < 0.05). DDP 2.5 mg/L and RAD001 2.5 nmol/L did not induce apoptosis of SGC7901/DDP cells alone (P > 0.05). When SGC7901/DDP cells were pretreated with RAD001 2.5 nmol/L, DDP 2.5 mg/L increased the apoptosis rate significantly compared to groups of control and DDP 2.5 mg/L alone (P < 0.05). Immunohistochemical staining (Table 5, Fig. 2) and Western blot analysis (Fig. 3) indicated that when SGC7901/DDP cells were pretreated with RAD001 2.5 nmol/L, the expression of P-gp, MRP1, and survivin decreased by different degrees. Our results have confirmed that RAD001 in combination with DDP could overcome chemoresistance of SGC7901/DDP cells by decreasing the levels of P-gp, MRP1, and survivin through the mTOR pathway.
authors.affiliation: Department of Pathology, Xuzhou Medical College, Xuzhou, China.
authors.forename: Liu
authors.initials: L
authors.lastname: Ying
authors.forename: Zhu
authors.initials: Z
authors.lastname: Zu-An
authors.forename: Liu
authors.initials: L
authors.lastname: Qing-Hua
authors.forename: Kong
authors.initials: K
authors.lastname: Qing-Yan
authors.forename: Liu
authors.initials: L
authors.lastname: Lei
authors.forename: Cui
authors.initials: C
authors.lastname: Tao
authors.forename: Wu
authors.initials: W
authors.lastname: Yong-Ping
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism; D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D002945:Cisplatin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D019008:Drug Resistance, Neoplasm / Q000187:drug effects*; D000068338:Everolimus; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D051034:Inhibitor of Apoptosis Proteins / Q000378:metabolism; D020128:Inhibitory Concentration 50; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000378:metabolism; D020123:Sirolimus / Q000031:analogs & derivatives* / Q000494:pharmacology; D013274:Stomach Neoplasms / Q000378:metabolism / Q000473:pathology; D000077022:Survivin; D013997:Time Factors
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents; D002945:Cisplatin; D000068338:Everolimus; D051034:Inhibitor of Apoptosis Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D020123:Sirolimus; D000077022:Survivin; C107489:BIRC5 protein, human; C421109:multidrug resistance-associated protein 1