ABSTRACT
PURPOSE: Gypenosides (Gyp) are the major components of Gynostemma pentaphyllum Makino. The authors investigated the effects of Gyp on cell morphology, viability, cell cycle distribution, and induction of apoptosis in human oral cancer SAS cells and the determination of murine SAS xenograft model in vivo. EXPERIMENTAL DESIGN: Flow cytometry was used to quantify the percentage of viable cells; cell cycle distribution; sub-G1 phase (apoptosis); caspase-3, -8, and -9 activity; reactive oxygen species (ROS) production, intracellular Ca(2+) determination; and the level of mitochondrial membrane potential (ΔΨ(m)). Western blotting was used to examine levels of apoptosis-associated proteins, and confocal laser microscopy was used to examine the translocation of proteins in cells. RESULTS: Gyp induced morphological changes, decreased the percentage of viable cells, caused G0/G1 phase arrest, and triggered apoptotic cell death in SAS cells. Cell cycle arrest induced by Gyp was associated with apoptosis. The production of ROS, increased intracellular Ca(2+) levels, and the depolarization of ΔΨ(m) were observed. Gyp increased levels of the proapoptotic protein Bax but inhibited the levels of the antiapoptotic proteins Bcl-2 and Bcl-xl. Gyp also stimulated the release of cytochrome c and Endo G. Translocation of GADD153 to the nucleus was stimulated by Gyp. Gyp in vivo attenuated the size and volume of solid tumors in a murine xenograft model of oral cancer. CONCLUSIONS: Gyp-induced cell death occurs through caspase-dependent and caspase-independent apoptotic signaling pathways, and the compound reduced tumor size in a xenograft nu/nu mouse model of oral cancer.
Subject(s)
Apoptosis/drug effects , Caspases/metabolism , Mouth Neoplasms/drug therapy , Signal Transduction/drug effects , Animals , Calcium/metabolism , Cell Cycle Checkpoints/drug effects , Cell Line, Tumor , Cell Survival/drug effects , Cytochromes c/metabolism , G1 Phase/drug effects , Gynostemma/chemistry , Humans , Male , Membrane Potential, Mitochondrial/drug effects , Mice , Mice, Inbred BALB C , Mice, Nude , Mouth Neoplasms/metabolism , Mouth Neoplasms/pathology , Plant Extracts/pharmacology , Protein Transport/drug effects , Proto-Oncogene Proteins c-bcl-2/metabolism , Reactive Oxygen Species/metabolism , Resting Phase, Cell Cycle/drug effects , Transcription Factor CHOP/metabolism , bcl-2-Associated X Protein/metabolism , bcl-X Protein/metabolismABSTRACT
Latex of Euphorbia antiquorum (EA) has inhibitory effects on several different cancer cell lines. However, the molecular mechanism of EA inhibitory effects on human cervical cancer HeLa cell growth has not been explored. EA induced apoptosis, which was characterized by morphological change, DNA fragmentation, increased sub-G1 population, and alterations in levels of apoptosis-associated proteins. Treatment with EA increased cell death and expression levels of caspase-8, -9, and -3. EA suppressed expression of Bcl-2, increased Bax, and reduced cleavage of Bid and the translocation of tBid to the mitochondria and the release of cytochrome c from mitochondria. EA caused a loss of mitochondrial membrane potential (ΔΨm) and an increase in cellular reactive oxygen species (ROS). EA-induced ROS formation was suppressed by cyclosporine A (an inhibitor of the ΔΨm) or allopurinol (an effective scavenger of ROS). EA also increased expression of Fas, FasL, and c-Jun N-terminal kinase (JNK), p38, and mitogen-activated protein kinase (MAPK) and decreased expression of extracellular signal-regulated kinase (ERK) 1/2-p. Co-treatment with the JNK inhibitor SP600125 inhibited EA-induced apoptosis and the activation of caspase-8, -9, and -3. Results of this study provide support for the hypothesis that EA causes cell death via apoptotic pathways in human cervical adenocarcinoma HeLa cells.
Subject(s)
Apoptosis/drug effects , Euphorbia/chemistry , JNK Mitogen-Activated Protein Kinases/metabolism , Latex/pharmacology , Reactive Oxygen Species/metabolism , Uterine Cervical Neoplasms/metabolism , Allopurinol/metabolism , Caspase 3/genetics , Caspase 3/metabolism , Caspase 8/genetics , Caspase 8/metabolism , Caspase 9/genetics , Caspase 9/metabolism , Cyclosporine/metabolism , Cytochromes c/metabolism , Female , HeLa Cells , Humans , JNK Mitogen-Activated Protein Kinases/genetics , MAP Kinase Signaling System/drug effects , Membrane Potential, Mitochondrial/drug effects , Mitochondria/drug effects , bcl-2-Associated X Protein/genetics , bcl-2-Associated X Protein/metabolismABSTRACT
HCV (Hepatitis C virus) that causes chronic liver disease. HCV NS5B RNA-dependent RNA polymerase (RbRp) and NS3 protease are able to affect virtual replication of genes. Computer-aided drug design (CADD) aims at designing new molecules with pharmacological activity. In this study, we used the Discovery Studio 2.0 program and the scoring function to estimate the Dock Score, piecewise linear potential 1 (PLP1), piecewise linear potential 2 (PLP2), and potential of mean force (PMF) score of novel compounds. In this way, novel compounds with "de novo evolution" can be found. Using the the pharmacophore features that are near the receptor pocket and the score functions to calculate scores for the ligand-receptor interaction, the new ligands were selected, developed and virtually placed in the binding site of the receptor. A new compound, EVO12, gave the best score, indicating that it may be an efficient polymerase inhibitor of HCV NS5B.
