title: Inducing cell cycle arrest and apoptosis by dimercaptosuccinic acid modified Fe3O4 magnetic nanoparticles combined with nontoxic concentration of bortezomib and gambogic acid in RPMI-8226 cells.
abstract: The purpose of this study was to determine the potential benefits of combination therapy using dimercaptosuccinic acid modified iron oxide (DMSA-Fe3O4) magnetic nanoparticles (MNPs) combined with nontoxic concentration of bortezomib (BTZ) and gambogic acid (GA) on multiple myeloma (MM) RPMI-8226 cells and possible underlying mechanisms. The effects of BTZ-GA-loaded MNP-Fe3O4 (BTZ-GA/MNPs) on cell proliferation were assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,4,-diphenyltetrazolium bromide (MTT) method. Cell cycle and apoptosis were detected using the terminal deoxyribonucleotidyl transferase (TdT)-mediated biotin-16-dUTP nick-end labeling (TUNEL) assay and flow cytometry (FCM). Furthermore, DMSA-Fe3O4 MNPs were characterized in terms of distribution, apoptotic morphology, and cellular uptake by transmission electron microscopy (TEM) and 4,6-diamidino-2-phenylindole (DAPI) staining. Subsequently, the effect of BTZ-GA/MNPs combination on PI3K/Akt activation and apoptotic-related protein were appraised by Western blotting. MTT assay and hematoxylin and eosin (HE) staining were applied to elevate the functions of BTZ-GA/MNPs combination on the tumor xenograft model and tumor necrosis. The results of this study revealed that the majority of MNPs were quasi-spherical and the MNPs taken up by cells were located in the endosome vesicles of cytoplasm. Nontoxic concentration of BTZ-GA/MNPs increased G2/M phase cell cycle arrest and induced apoptosis in RPMI-8226 cells. Furthermore, the combination of BTZ-GA/MNPs activated phosphorylated Akt levels, Caspase-3, and Bax expression, and down-regulated the PI3K and Bcl-2 levels significantly. Meanwhile, the in vivo tumor xenograft model indicated that the treatment of BTZ-GA/MNPs decreased the tumor growth and volume and induced cell apoptosis and necrosis. These findings suggest that chemotherapeutic agents polymerized MNPs-Fe3O4 with GA could serve as a better alternative for targeted therapeutic approaches to treat multiple myeloma.
authors.affiliation: Medical School, Southeast University, Nanjing, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Department of Pediatrics, Zhongda Hospital, Medical School, Southeast University, Nanjing, People's Republic of China.
authors.forename: Lixing
authors.initials: L
authors.lastname: Qiao
authors.affiliation: Department of Thyroid and Breast, the Fourth Central Hospital, Tianjin, People's Republic of China.
authors.forename: Xinchao
authors.initials: X
authors.lastname: Wang
authors.affiliation: Medical School, Southeast University, Nanjing, People's Republic of China.
authors.forename: Ravichandran
authors.initials: R
authors.lastname: Senthilkumar
authors.affiliation: Medical School, Southeast University, Nanjing, People's Republic of China.
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.affiliation: Medical School, Southeast University, Nanjing, People's Republic of China ; Department of Hematology and Oncology, Zhongda Hospital, Medical School, Southeast University, Nanjing, People's Republic of China.
authors.forename: Baoan
authors.initials: B
authors.lastname: Chen
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000633:toxicity; D017209:Apoptosis / Q000187:drug effects*; D000069286:Bortezomib / Q000737:chemistry / Q000633:toxicity; D059447:Cell Cycle Checkpoints / Q000187:drug effects*; D045744:Cell Line, Tumor; D006801:Humans; D058185:Magnetite Nanoparticles / Q000737:chemistry / Q000633:toxicity; D004113:Succimer / Q000737:chemistry*; D044004:Xanthones / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000970:Antineoplastic Agents; D058185:Magnetite Nanoparticles; D044004:Xanthones; D000069286:Bortezomib; C052659:gambogic acid; D004113:Succimer
keywords: DMSA-Fe3O4; PI3K/Akt; apoptosis; bortezomib; cell cycle; gambogic acid; magnetic nanoparticles