title: Celastrol induces apoptosis of human osteosarcoma cells via the mitochondrial apoptotic pathway.
abstract: Celastrol is an active compound extracted from the root bark of Triptergium wilfordii Hook F., also known as ̔Thunder of God Vine̓. It is a well-known Chinese medicinal herb that was found to inhibit tumor cell growth and promote apoptosis in several tumor cell lines. However, research into its effects on osteosarcoma cell apoptosis is still extremely limited. The present study was undertaken to determine the effect of celastrol on viability and apoptosis of osteosarcoma cells and furthermore, to illuminate the molecular mechanism of celastrol-induced osteosarcoma cell apoptosis. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay was used to evaluate the viability of the cells following treatment with celastrol. The effect of celastrol on the apoptotic rate of the cells was evaluated by flow cytometry using Annexin V-PE/7-AAD staining assay. Fluorescence microscopy was used to detect the morphological changes in the human osteosarcoma U-2OS cell lines. The expression of Bcl-2 family proteins, caspase-3, caspase-8, caspase-9, cytochrome c and PARP was measured by western blotting. We found that celastrol significantly inhibited the growth of osteosarcoma cells in a dose-dependent manner, particularly U-2OS cells. Furthermore, we observed that celastrol upregulated the expression of the pro-apoptotic proteins Bax and cytochrome c and altered the ratio of Bax/Bcl-2, and triggered the mitochondrial apoptotic pathway, resulting in caspase-3 and -9 activation and PARP cleavage. To conclude, the results indicate that celastrol inhibits the proliferation of human osteosarcoma cancer cells by inducing apoptosis via the mitochondrial-dependent pathway.
authors.affiliation: Department of Orthopedics, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China.
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Yu
authors.affiliation: Department of Orthopedics, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Orthopedics, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China.
authors.forename: Changlin
authors.initials: C
authors.lastname: Fu
authors.affiliation: Department of Orthopedics, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Orthopedics, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China.
authors.forename: Tao
authors.initials: T
authors.lastname: Nie
authors.affiliation: Department of Orthopedics, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China.
authors.forename: Fan
authors.initials: F
authors.lastname: Zou
authors.affiliation: Department of Orthopedics, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China.
authors.forename: Runsheng
authors.initials: R
authors.lastname: Guo
authors.affiliation: Department of Orthopedics, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China.
authors.forename: Hucheng
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Orthopedics, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Department of Orthopedics, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China.
authors.forename: Min
authors.initials: M
authors.lastname: Dai
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D001859:Bone Neoplasms / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D005434:Flow Cytometry; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects*; D012516:Osteosarcoma / Q000473:pathology*; D053978:Pentacyclic Triterpenes; D014315:Triterpenes / Q000494:pharmacology*
chemical_list: D000970:Antineoplastic Agents; D053978:Pentacyclic Triterpenes; D014315:Triterpenes; C050414:celastrol