Aim To study the mechanisms of Pseudolaric acid B(PAB)-induced MCF-7 cell apoptosis and mitotic arrest.Methods MTT assay was performed to assess the cell growth inhibition,contrast phase microscope was used to observe cellular morphologic alteration,and the change of DNA was detected by fluorescent microscopy.The distribution of cell cycle was determined by flow cytometric analysis of propidium iodide staining,and the protein expression was examined by Western blot analysis.Results PAB inhibited MCF-7 cell growth in a dose-and time-dependent manner.4 ?mol?L-1 PAB induced DNA condensation at 24 h.PAB cleaved PARP in a time-dependent manner.At 36 h,PAB up-regulated the expression of cdc 2 and nuclear cyclin B1.Fas antagonistic antibody UB2 had no effect on apoptosis,but agonistic antibody CH11 enhanced the apoptosis induced by PAB.UB2 exerted no effect on cell cycle arrest,and CH11 had the same action as UB2 except for reducing the mitotic arrest through enhancing apoptotic subdiploid peak.Conclusion PAB inhibited MCF-7 cell growth through mitotic arrest and apoptosis.Apoptosis and mitotic arrest were independent of Fas pathway.

AIM To study the mechanisms of oridonin-induced HeLa cell apoptosis. METHODS Morphological observation, agarose gel electrophoresis, LDH release and caspase inhibitors were used. RESULTS Oridonin had significant apoptotic effect on HeLa cells in a dose- and time-dependent manner. The marked morphological changes including condensed chromatin, nuclear fragmentation and apoptotic bodies and DNA ladder in agarose gel was observed. The activity of caspase-3 was increased about 2 times of control value after treatment with oridonin. CONCLUSION Oridonin induces HeLa cell apoptosis through caspase pathway.

AIM To study the mechanisms of shikonin-induced HeLa cell apoptosis. METHODS Cytotoxicity assay by MTT, DNA fragmentation assay, LDH activity-based cytotoxicity assay and Western blot analysis were carried out. RESULTS Shikonin inhibited HeLa cell growth in a dose- and time-dependent manner. Apoptotic cell death was observed within 24 h after 40 ?mol?L -1 shikonin treatment. Shikonin induced HeLa cell apoptosis involved in the activation of caspase-3 and caspase-8, which is similar to the Fas or TNF-? signaling transduction pathways. CONCLUSION Shikonin induced caspase-dependent apoptosis in HeLa cells.

AIM: To study the molecular biological mechanism and signal transduction pathway of interleukin-1? (IL-1?)-induced apoptosis in A375-S2 melanoma cells. METHODS: Photomicrocropy showed typical apoptotic changes. The cytotoxic effect of IL-1? in vitro and influences of caspases in this effect were measured by MTT assay. The cytotoxicity of cells was assessed by LDH-based assay. Degradation of DNA was detected by agarose gel electrophoresis. RESULTS: The inhibitory effect of IL-1? on A375-S2 cell growth was in a dose and time-dependent manner, and cell death rate reached more than 90% at 72 h after treatment with 10~(-9)mol/L IL-1?. The inhibitors of caspase-family, -1, -3, -8, -9, and -10, partially blocked cell death at early stage. LDH assay showed that major IL-1?-induced cell death was apoptosis, and in a dose and time-dependent manner. Typical apoptotic DNA ladder was observed in agarose gel electrophoresis. CONCLUSION: IL-1? induced apoptosis in melanoma A375-S2 cells by activating caspase pathway. [

BACKGROUND: Uterine cervix cancer is one of the diseases to damage female health and degrade quality of life. It has been a hot spot to decrease the side effects of radiotherapy and chemotherapy and anti-tumor medicine by using Chinese medicine in medical domain. In Europe, silymarin had been used to treat hepatitis. It had little toxic action and large contents in Chinese herb. Therefore, many researchers are studying its anti-tumor effects now.OBJECTIVE: To study the pharmacological mechanism of silymarin on human cervical cancer cell.DESIGN: The cells cultured in 10% serum medium served as negative control group in vitro.MATERIALS: The experiment was finished in the China-Japan Research Institute of Medical and Pharmaceutical Sciences in Shenyang Pharmaceutical University; Department of Pathological Science of Showa Medical UniversityMATERIASLS: Human cervical cancer cell (HeLa) is the preservative cell line of American ATCC in the Lab. The experiment was completed in the Cell Lab of China-Japan Research Institute of Medical and Pharmaceutical Sciences in Shenyang Pharmaceutical University from Feburary 2003 to July 2003.METHODS: HeLa cell death ratio was measured by methyl thiazol tetrazolium(MTT) assay. Cellular morphologic changes were observed by phase-contrast and fluorescence microscopy. Cell cycle distribution was analyzed by flow cytometry.MAIN OUTCOME MEASURES: The changes of cell death ratio and cell cycle distribution.RESULTS: Silymarin-induced HeLa cell death was relevant to the content of serum in medium. At the does of 80 μmol /L silymarin, the cell death ratio in serum-free group reached 85.27%. The cell death ratio in 5% and 10%serum groups was 35.53% and 7.71% respectively. Morphological changes of HeLa cells demonstrated that silymarin induced HeLa cell death through apoptotic pathway at lower concentration in serum-free condition. Flow cytometry analysis showed that silymarin induced 70. 04% cells death, most of which were in G0/G1 phase.CONCLUSION: Silymarin mainly induce G0/G1 phase HeLa cell death through apoptotic pathway in serum-free medium.

AIM: To study the effect of oridonin on the phagocytosis of apoptotic U937 cells by macrophage-like cells. METHODS: DNA agarose gel electrophoresis, Giemsa staining, Hoechst 33258 staining and photomicroscopical observation were used. RESULTS: UV irradiation (2.4 J/cm~2, 4 min) induced U937 cell apoptosis. Marked DNA fragmentation in agarose gel electrophoresis was observed. Oridonin augmented phagocytosis of apoptotic U937 cells by U937 cell-derived macrophages in a time- and dose-dependent manner. However, less effect on synthetic fluoresbrite micropheres was observed. The oridonin-augmented phagocytosis was attenuated by anti-human TNF? or anti-human IL-1? antiserum. In addition, the similar effect of phagocytosis was observed in oridonin-treated human monocyte-derived macrophages at 4 day maturation. CONCLUSION: Oridonin enhances phagocytosis of apoptotic U937 cells by macrophage-like cells. The releases of TNF? and IL-1? are involved in this mechanism.

AIM: To compare the cytotoxic effect of evodiamine with chemotherapy drugs on A375-S2 cells, and to examine the relationship between the effects of PKC and ERK on evodiamine-induced cell death. METHODS: MTT assay and Western blot analysis were applied. RESULTS: Compared to actinomycin D, cisplatin and 5-FU, evodiamine showed less cytotoxic effects on A375-S2 cells, but it induced more significant inhibition of proliferation in A375-S2 cells incubated with evodiamine for 24 h, followed by continuous culture in drug-free medium. The activation of PKC induced by 10 ?g?L -1 PMA partially blocked evodiamine-induced cell death, which was reversed by PKC and ERK inhibitors. Moreover, evodiamine down-regulated the expressions of ERK and phosphorylated ERK. CONCLUSION: Evodiamine has a strong inhibitory influence on proliferation of A375-S2 cells, even after removal of evodiamine. Evodiamine blocks the protective role of ERK to A375-S2 cells through the downregulation of ERK and phosphorylated ERK expression. [

AIM: To examine the apoptotic pathway of norcantharidin (NCTD)-induced HeLa cells death. METHODS: MTT, photomicroscopical observation, DNA agarose gel electrophoresis, LDH release and Western blot analysis were used. RESULTS: NCTD induced HeLa cells apoptosis and the apoptosis was partially reversed by the inhibitors of caspase-family (-3, -8, -10). The activities of caspase-3, -8 and -9 were significantly increased after treated with NCTD. The expression of the inhibitor of caspase-3 activated DNase (ICAD) was decreased in a time dependent manner. CONCLUSION: NCTD induces HeLa cells apoptosis through activating caspase pathways.

AIMTo study the role of PKC in evodiamine-induced A375-S2 cell death.

METHODSRatio of apoptosis induced by evodiamine was determined by TUNEL assay. MTT assay was carried out to assess cytotoxic effect of evodiamine. The influence on expression of ERK, phospho-ERK and Bcl-2 was detected by Western blotting analysis.

RESULTSTUNEL assay indicated that apoptosis was the type of A375-S2 cell death induced by evodiamine treatment for 24 h. Both staurosporine (inhibitor of PKC) and PD98059 (inhibitor of ERK) cooperated with evodiamine to further induce A375-S2 cell death. Evodiamine inhibited PKC activity, down-regulated the expression of ERK, phospho-ERK and Bcl-2, and staurosporine was capable of augmenting these effects induced by evodiamine.

CONCLUSIONPKC lies upstream and exhibits regulatory effect on ERK and Bcl-2 in evodiamine-induced cell death.

Apoptosis ; drug effects ; Cell Line, Tumor ; Evodia ; chemistry ; Extracellular Signal-Regulated MAP Kinases ; antagonists & inhibitors ; metabolism ; Flavonoids ; pharmacology ; Humans ; Melanoma ; pathology ; Plant Extracts ; isolation & purification ; pharmacology ; Plants, Medicinal ; chemistry ; Protein Kinase C ; antagonists & inhibitors ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Quinazolines ; isolation & purification ; pharmacology ; Staurosporine ; pharmacology

OBJECTIVETo study the mechanisms of pseudolaric acid B-induced apoptosis on A375-S2 cells.

METHODMTT, fluorescence microscope observation, DNA agarose gel electrophoresis and Western blot analysis wereused.

RESULTPseudolaric acid Binduces A375-S2 cell apoptosis in a time and dose-dependent manner. Apoptotic bodies and DNA ladder were observed in 5 micromol x L(-1) pseudolaric acid B-treated A375-S2 cells for 36 h. The expression of Bcl-2, Bcl-xL and ICAD was reduced time dependently, whereas the expression of Bax was increased.

CONCLUSIONThe major cause of pseudolaric acid B induced cytotoxicity on A375-S2 cells was apoptosis. Mitochondria proteins and ICAD might be involved in the apoptotic pathways of pseudolaric acid B-treated A375-S2 cells.

Apoptosis ; drug effects ; Apoptosis Regulatory Proteins ; Cell Line, Tumor ; Diterpenes ; isolation & purification ; pharmacology ; Dose-Response Relationship, Drug ; Humans ; Melanoma ; metabolism ; pathology ; Pinaceae ; chemistry ; Proteins ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; bcl-2-Associated X Protein ; bcl-X Protein