目的:探讨小鼠卵母细胞不同细胞周期时相中,由于p34cdc2不同磷酸化状态所引起的电泳迁移率变化。方法:用免疫印迹(W estern b lot)技术观察G2期和MⅡ期小鼠卵母细胞中p34cdc2电泳迁移率的变化。结果:p34cdc2在G2期只表现两条带即上、中...目的:探讨小鼠卵母细胞不同细胞周期时相中,由于p34cdc2不同磷酸化状态所引起的电泳迁移率变化。方法:用免疫印迹(W estern b lot)技术观察G2期和MⅡ期小鼠卵母细胞中p34cdc2电泳迁移率的变化。结果:p34cdc2在G2期只表现两条带即上、中带;而MⅡ期表现为中、下带。结论:可以用电泳迁移率的变化作为观察p34cdc2磷酸化状态的一种方法。展开更多
Full grown oocytes derived from Bufo Bufo gargarizans rearing at high temperature environment (24℃),never underwent GVBD after progesterone treatment. No p34cdc2, H1 kinase activity was detected in the oocytes after ...Full grown oocytes derived from Bufo Bufo gargarizans rearing at high temperature environment (24℃),never underwent GVBD after progesterone treatment. No p34cdc2, H1 kinase activity was detected in the oocytes after progesterone stimulation or OA microinjection; Western blotting analysis showed that the level of p3cdc2, and p33 in the oocytes are significantly lower than those in the oocytes derived from the hibernating toads (below 10 ℃). 25S-Met incorporation analysis showed that when the oocytes were incubated at 6℃, synthesis of about thirty defferent polypeptides was promoted or induced, including p34cdc2 and some other p13suc1-binding proteins. All these results indicated that a low temperature environment is essential for the oocytes of Bufo Bufo gargarizans to express and store some cell cycle drivers and its regulators, and to gain the maturation competence. These results will also provide a new clue for explaining the molecular mechanisms why gametogenesis of some organisms depends on a relative low temperature and how to maintain the geographical distribution of some animals.展开更多
OBJECTIVE To investigate the influence of O-(4-ethoxyl-butyl)- berbamine(EBB)on the expression of cyclin B1 and cdc2-p34 in the human drug-resistant breast cancer MCF-7/ADR cell line. METHODS The MTT assay was used to...OBJECTIVE To investigate the influence of O-(4-ethoxyl-butyl)- berbamine(EBB)on the expression of cyclin B1 and cdc2-p34 in the human drug-resistant breast cancer MCF-7/ADR cell line. METHODS The MTT assay was used to assess the cytotoxicity of EBB.Different levels of EBB were added to different cell lines at series of time points solely or combined with doxorubicin(DOX) to detect the effect on the expression of cyclinB1 and cdc2-p34 by Western blots.cdc2-p34 tyrosine phosphorylation was detected by immunoprecipitation.In addition,apoptosis and cytoplastic Ca 2+ concentrations were systematically examined by laser scanning confocal microscopy(LSCM). RESULTS EBB showed little inhibitory activity on human umbilical vein endothelial cells(ECV304),whereas EBB inhibited cell growth(IC50 range,4.55~15.74μmol/L)in a variety of sensitive and drug-resistance cell lines.EBB also down-regulated the expression of cyclin B1 and cdc2-p34 in a concentration and time dependent manner,which was an important reason for the G2/M phase arrest.EBB was shown to induce apoptosis of MCF-7/ADR cells while increasing the level of cytoplastic Ca 2+ . CONCLUSION The low cytotoxicity of EBB suggests it may be useful as a rational reversal agent.The effect of EBB on cell cycle arrest and related proteins,apoptosis,and cytoplastic Ca 2+ concentration may be involved in reversing multidrug resistance.展开更多
文摘目的:探讨小鼠卵母细胞不同细胞周期时相中,由于p34cdc2不同磷酸化状态所引起的电泳迁移率变化。方法:用免疫印迹(W estern b lot)技术观察G2期和MⅡ期小鼠卵母细胞中p34cdc2电泳迁移率的变化。结果:p34cdc2在G2期只表现两条带即上、中带;而MⅡ期表现为中、下带。结论:可以用电泳迁移率的变化作为观察p34cdc2磷酸化状态的一种方法。
文摘Full grown oocytes derived from Bufo Bufo gargarizans rearing at high temperature environment (24℃),never underwent GVBD after progesterone treatment. No p34cdc2, H1 kinase activity was detected in the oocytes after progesterone stimulation or OA microinjection; Western blotting analysis showed that the level of p3cdc2, and p33 in the oocytes are significantly lower than those in the oocytes derived from the hibernating toads (below 10 ℃). 25S-Met incorporation analysis showed that when the oocytes were incubated at 6℃, synthesis of about thirty defferent polypeptides was promoted or induced, including p34cdc2 and some other p13suc1-binding proteins. All these results indicated that a low temperature environment is essential for the oocytes of Bufo Bufo gargarizans to express and store some cell cycle drivers and its regulators, and to gain the maturation competence. These results will also provide a new clue for explaining the molecular mechanisms why gametogenesis of some organisms depends on a relative low temperature and how to maintain the geographical distribution of some animals.
基金This work was supported by grants from the National Nature Science Foundation of China(No.30572203,30570772)the Key Fund of Science of TianJin Municipal Government(No.07JCZDJC04900)
文摘OBJECTIVE To investigate the influence of O-(4-ethoxyl-butyl)- berbamine(EBB)on the expression of cyclin B1 and cdc2-p34 in the human drug-resistant breast cancer MCF-7/ADR cell line. METHODS The MTT assay was used to assess the cytotoxicity of EBB.Different levels of EBB were added to different cell lines at series of time points solely or combined with doxorubicin(DOX) to detect the effect on the expression of cyclinB1 and cdc2-p34 by Western blots.cdc2-p34 tyrosine phosphorylation was detected by immunoprecipitation.In addition,apoptosis and cytoplastic Ca 2+ concentrations were systematically examined by laser scanning confocal microscopy(LSCM). RESULTS EBB showed little inhibitory activity on human umbilical vein endothelial cells(ECV304),whereas EBB inhibited cell growth(IC50 range,4.55~15.74μmol/L)in a variety of sensitive and drug-resistance cell lines.EBB also down-regulated the expression of cyclin B1 and cdc2-p34 in a concentration and time dependent manner,which was an important reason for the G2/M phase arrest.EBB was shown to induce apoptosis of MCF-7/ADR cells while increasing the level of cytoplastic Ca 2+ . CONCLUSION The low cytotoxicity of EBB suggests it may be useful as a rational reversal agent.The effect of EBB on cell cycle arrest and related proteins,apoptosis,and cytoplastic Ca 2+ concentration may be involved in reversing multidrug resistance.
