title: Timosaponin A-III reverses multi-drug resistance in human chronic myelogenous leukemia K562/ADM cells via downregulation of MDR1 and MRP1 expression by inhibiting PI3K/Akt signaling pathway.
abstract: One of the major causes of failure in chemotherapy for patients with human chronic myelogenous leukemia (CML) is the acquisition of multidrug resistance (MDR). MDR is often associated with the overexpression of drug efflux transporters of the ATP-binding cassette (ABC) protein family. Timosaponin A-III (TAIII), a saponin isolated from the rhizome of Anemarrhena asphodeloides, has previously demonstrated the ability to suppress certain human tumor processes and the potential to be developed as an anticancer agent. Nevertheless, the ability of TAIII to reverse MDR has not yet been explored. In this study, the adriamycin (ADM) resistance reversal effect of TAIII in human CML K562/ADM cells and the underlying mechanism was investigated. The Cell Counting Kit-8 (CCK-8) assay showed that TAIII had a reversal effect on the drug resistance of K562/ADM cells. Flow cytometry assay showed increased intracellular accumulation of ADM after cells were pretreated with TAIII, and the changes in the accumulation of rhodamine-123 (Rho-123) and 5(6)-carboxyfluorescein diacetate (CFDA) dye in K562/ADM cells were determined to be similar to the changes of intracellular accumulation of ADM. After pretreatment of cells with TAIII, the decreasing expression of P-gp and MRP1 mRNA was examined by reverse transcription polymerase chain reaction (RT-PCR). Western blotting showed TAIII inhibiting P-gp and MRP1 expression depended on the PI3K/Akt signaling pathway by decreasing the activity of p-Akt. Moreover, wortmannin an inhibitor of PI3K/Akt signaling pathway has a strong inhibitory effect on the expression of p-Akt, P-gp and MRP1. Besides, the combined treatment with TAIII did not have an affect on wortmannin downregulation of p-Akt, P-gp and MRP1. Taken together, our findings demonstrate, for the first time, that TAIII induced MDR reversal through inhibition of P-gp and MRP1 expression and function with regained adriamycin sensitivity which might mainly correlate to the regulation of PI3K/Akt signaling pathway.
authors.affiliation: Department of Pediatrics, The Affiliated Hospital of Binzhou Medical University, Binzhou, Shandong 256603. P.R. China.
authors.forename: Jie-Ru
authors.initials: JR
authors.lastname: Chen
authors.affiliation: Department of Pediatrics, The Affiliated Hospital of Binzhou Medical University, Binzhou, Shandong 256603. P.R. China.
authors.forename: Xiu-Hong
authors.initials: XH
authors.lastname: Jia
authors.affiliation: Department of Pediatrics, The Affiliated Hospital of Binzhou Medical University, Binzhou, Shandong 256603. P.R. China.
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Pediatrics, The Affiliated Hospital of Binzhou Medical University, Binzhou, Shandong 256603. P.R. China.
authors.forename: Ying-Jie
authors.initials: YJ
authors.lastname: Yi
authors.affiliation: Department of Pediatrics, The Affiliated Hospital of Binzhou Medical University, Binzhou, Shandong 256603. P.R. China.
authors.forename: Jian-Yong
authors.initials: JY
authors.lastname: Wang
authors.affiliation: Department of Biochemistry and Molecular Biology, Key Laboratory of Tumour Molecular Biology, Binzhou Medical University, Yantai, Shandong 264003, P.R. China.
authors.forename: You-Jie
authors.initials: YJ
authors.lastname: Li
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B / Q000235:genetics / Q000378:metabolism; D000970:Antineoplastic Agents / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D015536:Down-Regulation; D004317:Doxorubicin / Q000494:pharmacology; D018432:Drug Resistance, Multiple / Q000187:drug effects*; D019008:Drug Resistance, Neoplasm / Q000187:drug effects*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D020014:K562 Cells; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism*; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism; D012503:Saponins / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D013256:Steroids / Q000494:pharmacology*
chemical_list: D018435:ATP Binding Cassette Transporter, Subfamily B; D000970:Antineoplastic Agents; D004317:Doxorubicin; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D012503:Saponins; D013256:Steroids; C513055:ABCB1 protein, human; C543146:timosaponin AIII; C421109:multidrug resistance-associated protein 1