ABSTRACT
<p><b>OBJECTIVE</b>To explore the molecular mechanism of realgar-induced apoptosis of cervical cancer cells.</p><p><b>METHODS</b>The cervical cancer cell line Siha was used to determine the cell viability and apoptosis after treatment with realgar using MTT assay and flow cytometry. The activities of caspase-3, -8, and -9 were detected by fluorescence resonance energy transfer technology and colorimetric assay, while the levels of Bcl-2, cytochrome c, and Bax were detected by Western blot method.</p><p><b>RESULTS</b>Induction of apoptosis by realgar was detected in Siha cell line in a dose-dependent manner. The apoptosis was accompanied by a significant increase in cytochrome c release and activation of caspase-3 and caspase-9 but not caspase-8. Further, the realgar-induced apoptosis was inhibited by a broad-spectrum caspase inhibitor, a caspase-3 inhibitor, and a caspase-9 inhibitor but not by a caspase-8 inhibitor. Bcl-2 and Bax protein expressions were not changed by realgar.</p><p><b>CONCLUSION</b>The induction of apoptosis by realgar is mediated through a cytochrome c-dependent pathway, which sequentially activates caspase-9 and caspase-3.</p>
Subject(s)
Female , Humans , Apoptosis , Physiology , Arsenicals , Pharmacology , Caspase 3 , Metabolism , Caspase 8 , Metabolism , Caspase 9 , Metabolism , Caspase Inhibitors , Cell Line, Tumor , Cell Survival , Physiology , Cytochromes c , Metabolism , Dose-Response Relationship, Drug , Enzyme Activation , Enzyme Inhibitors , Pharmacology , Fluorescence Resonance Energy Transfer , Sulfides , Pharmacology , Uterine Cervical Neoplasms , Drug Therapy , Metabolism , PathologyABSTRACT
<p><b>OBJECTIVE</b>To study the growth-inhibitory and apoptosis-inducing effects of realgar nanometer suspension in human carcinoma cervical cell Siha line, and the effect on HPV16E6/E7 oncogene expression.</p><p><b>METHOD</b>A " micro-jet efflux" strategy was used for the preparation of realgar nanometer suspension. Siha cells were treated with various concentrations (6.25, 12.5, 25, 50 mg x L(-1)) of realgar nanometer suspension for different hours (12, 24, 48, 72 h). The effect of realgar nanometer suspension on Siha cell growth suppression was detected by MTT method. Special morphological changes of apoptosis were observed by light and transmission electron microscopy (TEM) and DNA fragments electrophoresis. The apoptotic rates were quantified by flow cytometry (FCM). The expression of HPV16E6/E7 mRNA was assayed by RT-PCR.</p><p><b>RESULT</b>After being treated with 25-50 mg x L(-1) realgar nanometer suspension for 48, 72 h, the survival of Siha cells decreased, and the rate of apoptosis markedly increased. With TEM and DNA electrophoresis, the special morphological changes were found. The apoptotic rates of Siha cells treated with realgar nanometer suspension were significantly higher than those in the control group (P < 0.01). G0-G1 phase arrest appeared following the treatment with realgar nanometer suspension in 25 and 50 mg x L(-1) 48 h. RT-PCR assay revealed that realgar nanometer suspension reduced HPV16E6/E7 gene expression.</p><p><b>CONCLUSION</b>Realgar nanometer suspension can inhibit the proliferation of human carcinoma cervical cell Siha line and induce the cell apoptosis. The mechanism may be related to the down-regulation of HPV16E6/E7 oncogene expression.</p>
Subject(s)
Humans , Apoptosis , Arsenicals , Pharmacology , Cell Line, Tumor , Flow Cytometry , Gene Expression , Microscopy, Electron, Transmission , Oncogene Proteins, Viral , Genetics , Papillomavirus E7 Proteins , Repressor Proteins , Genetics , Reverse Transcriptase Polymerase Chain Reaction , Sulfides , PharmacologyABSTRACT
0.05),but expression of VEGF,GLUT1 and MDR1 were all enhanced and overall proliferation was promoted,apoptosis inhibited [(11.46?0.28)% vs (29.27?0.18)%,(15.77? 0.49)% vs (31.13?0.08)%],and transmembrane behavior enhanced [(37?12)% vs (26?7)%, (40?9)% vs (28?5)%],and the variations were significant (P