Neferine increases STI571 chemosensitivity via inhibition of P-gp expression in STI571-resistant K562 cells.
We investigated the effects of neferine (Nef) on STI571 sensitivity and the possible mechanism in STI571-resistant K562/G01 cells. We observed cell proliferation by the modified MTT (methyl thiazolyl tetrazolium) assay. We determined the intracellular concentration of STI571 in K562/G01 cells by high-performance liquid chromatography (HPLC), the expression of P-glycoprotein (P-gp) by Western blotting, and the expression of MDR-1 mRNA by reverse transcriptase-polymerase chain reaction (RT-PCR). We observed that drug resistance to STI571 for K562/G01 cells was 43.99-fold higher than that for K562 cells. We also observed that a low concentration of Nef (<8 μM) and verapamil hydrochloride (VRP) (<10 μM) showed no direct cytotoxicity but significantly reduced the 50% cell growth inhibitory concentration (IC(50)) values of STI571 in K562/G01 cells. The reverse multiples for 8 μM Nef and 10 μM VRP were approximately two-fold. Both Nef (8 μM) and VRP (10 μM) decreased MDR-1 mRNA and P-gp protein expression and increased intracellular STI57I concentrations significantly in K562/G01 cells. Nef is a candidate chemical that can increase STI571 chemosensitivity in STI571-resistant K562 cells by inhibition of P-gp expression and increasing intracellular STI571 accumulation.
Department of Pharmacy, Xiangya Hospital, Central South University, Changsha, China.
Qun
Q
Qin
Xiao-Ping
XP
Chen
Zhou-Sheng
ZS
Yang
Yu-Hang
YH
Xiao
Hui
H
Min
Yuan-Jian
YJ
Li
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D001549:Benzamides; D044182:Benzylisoquinolines / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects; D019008:Drug Resistance, Neoplasm / Q000187:drug effects*; D004357:Drug Synergism; D015973:Gene Expression Regulation, Leukemic / Q000187:drug effects; D006801:Humans; D000068877:Imatinib Mesylate; D020014:K562 Cells; D010879:Piperazines / Q000494:pharmacology*; D011743:Pyrimidines / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D001549:Benzamides; D044182:Benzylisoquinolines; D010879:Piperazines; D011743:Pyrimidines; D012333:RNA, Messenger; C057222:neferine; D000068877:Imatinib Mesylate