Apoptotic effects of curcumin on human osteosarcoma U2OS cells.
OBJECTIVE
Curcumin, an active ingredient derived from the rhizome of the plant, Curcuma longa, has antioxidant, anti-inflammatory and anti-cancer activities. The aims of this study were to examine whether curcumin can induce apoptosis in an osteosarcoma cell line.


METHODS
Curcumin-induced apoptosis in human osteosarcoma U2OS cells was investigated using morphological analysis, marked nuclear condensation and fragmentation of chromatin, which were observed by Hoechst 33258 staining and DNA ladder formation. The U2OS cells were treated with or without curcumin. Cell viability was assessed by the 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium (MTT) method. Cell-cycle, apoptosis and apoptosis-related proteins in U2OS cells were evaluated by flow cytometry and western blotting.


RESULTS
Curcumin showed growth inhibitory effects on U2OS cells in a dose-and time-dependent manner, inducing significant G1 arrest and apoptosis in U2OS cells. This curcumin-induced apoptosis in U2OS cells was accompanied by up-regulation of Bax, Bak, and p-Bad and down-regulation of Bcl-2, but no effect on the levels of Bcl-X(L) or Bad proteins was noted. Moreover, curcumin treatment resulted in a significant reduction of mitochondrial membrane potential and increase in the concentrations of mitochondrial cytochrome C and caspase-3.


CONCLUSIONS
Multiple molecular pathways are involved in curcumin-induced apoptosis of human U2OS cells. These include pro-and anti-apoptotic Bcl-2 family proteins, mitochondrial membrane potential, mitochondrial cytochrome C and caspase-3.
Department of Orthopaedic Surgery, Yijishan Hospital, Wannan Medical College, Wuhu, Anhui, China.
Song
S
Jin
Hong-guang
HG
Xu
Jing-nan
JN
Shen
Xu-wu
XW
Chen
Hong
H
Wang
Jia-guo
JG
Zhou
D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D014408:Biomarkers, Tumor / Q000096:biosynthesis / Q000235:genetics; D015153:Blotting, Western; D001859:Bone Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D003474:Curcumin / Q000494:pharmacology*; D004273:DNA, Neoplasm / Q000032:analysis; D005434:Flow Cytometry; D006801:Humans; D012516:Osteosarcoma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D015854:Up-Regulation / Q000187:drug effects
D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; D003474:Curcumin