[Effect of dioxin on apoptosis of osteogenic sarcoma cells and regulation on gene expression of insulin-like growth factor binding protein 6].
OBJECTIVE
To investigate the effect of the environmental carcinogenic factor-TCDD (2, 3, 7, 8-tetrachlorodibenzo-p-dioxin) on cell apoptosis and gene regulation of insulin-like growth factor binding protein 6 (IGFBP-6) in osteogenic sarcoma (SaOS-2) cells.


METHODS
The SaOS-2 cells were cultured with TCDD (1 x 10(-9), 1 x 10(-8), 1 x 10(-7) mol/L) for 24 hours. The MTT reduction assay and flow cytometry were used to measure the cell proliferation and the cell apoptosis in TCDD-treated SaOS-2 cells. The Nitrophenol phosphate salt method was used to measure activity of alkaline phosphatase (ALP) in SaOS-2 cells. The IGFBP-6 mRNA and protein in SaOS-2 cells were detected by reverse transcription polymerase chain reaction (RT-PCR) and western blotting analysis.


RESULTS
SaOS-2 cell proliferation was up-regulated with TCDD (1 x 10(-9), 1 x 10(-8), and 1 x 10(-7) mol/L) about 20%, 47% and 93% (18.4 +/- 4.5, 22.5 +/- 3.6 and 29.4 +/- 4.2), respectively. The synthesis of ALP was up-regulated about 28%, 95%, and 142% (1.12 +/- 0.28, 1.58 +/- 0.14 and 1.96 +/- 0.17), respectively (P < 0.05). The cell apoptosis was down-regulated in dose-dependent biological manner about 5%, 26% and 52%, respectively (P < 0.05). The expression of IGFBP-6 mRNA and protein was decreased in 1 x 10(-7) mol/L TCDD-treated SaOS-2 cells about 76% and 72% (P < 0.05).


CONCLUSIONS
TCDD at low concentration may have the negative effect on cell apoptosis and down-regulation on gene expression of IGFBP-6 in SaOS-2 cells.
Guo
Lei
L
Department of Endocrinology, The First Affiliated Hospital, China Medical University, Shenyang, China.
Zhao
Yu-Yan
YY
Zhang
Shi-Liang
SL
Liu
Kui
K
Gao
Xiao-Yu
XY
D017209:Apoptosis / Q000187:drug effects*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D006801:Humans; D018976:Insulin-Like Growth Factor Binding Protein 6 / Q000235:genetics / Q000378:metabolism*; D012516:Osteosarcoma / Q000378:metabolism / Q000473:pathology*; D000072317:Polychlorinated Dibenzodioxins / Q000633:toxicity*; D012333:RNA, Messenger / Q000235:genetics
D018976:Insulin-Like Growth Factor Binding Protein 6; D000072317:Polychlorinated Dibenzodioxins; D012333:RNA, Messenger