Criegee intermediate is believed to play an important role in the atmospheric chemistry.Because of its short life and the difficulty in experimental study, we carried out ah initio calculations on the thermochemistry ...Criegee intermediate is believed to play an important role in the atmospheric chemistry.Because of its short life and the difficulty in experimental study, we carried out ah initio calculations on the thermochemistry of the Criegee involving reactions in this study. Thermochemistrydata of reaction enthalpies and Gibbs free energies for four different stable structures of the Criegeeintermediates (singlet CH2OO ①1 A1 in C2v, triplet CH2OO ②3B1 in C2v, singlet CH2OO ③1A’ in Cs and triplet CH2OO ④ in C1 symmetry) involved in some of the gas-phase reactions were calculated at the standard Gaussian-2 [G2(MP2) and G2] and a modified G2, G2(fu1)[10],levels of theory. Relative energies among those Criegees and formic acid were compared. Chemical reactions incltlde the formation of Criegees, re-arrangement from Criegee to formic acid, dissociations (producing CH2(3B1)+O2, CH2(1A1)+O2, CO2+H2, CO2+2H, CO+H2O, OH+HCO) andthe reactions between Criegee and NO/H2O. Standard equilibrium constants for some reactions were investigated and may be obtained for all of the rest reactions involved in this study by the standard Gibbs free energies. It is shown that the formation of Criegee①-④ by ethylene and ozone, the re-arrangement from any Criegee to formic acid, the dissociation in producing CO2+O2and CO+H2O and the reactions between any Criegee and NO/H2O are all favourable thermodynamicaly. The dissociation in forming CO2+2H and OH+HCO is less favourable. While the dissociation in forming carbene (either in 3B1 or 1A1 state) is not allowed by values. Standard enthalpies of formation at 298 K for the four Criegees were predicted at the G2(ful) level of theory. Each value is the average value from ten of the above reactions and they are -4.3, 74.8,98.9 and 244.6 kJ mol-1 at the G2(ful) level for Criegee ① to Criegee ④, respectively. In addition, tile standard enthalpy of formation at 298 K for HOCH2OOH is further predicted to be -315.6 kJ mol-1 at the G2(MP2) level.展开更多
目的:验证G2/S期应答相关蛋白1(G2 and S phase-expressed protein 1,GTSE1)在原发性肝癌组织及细胞株中高表达,并探讨其表达下调对肝癌细胞凋亡的影响。方法:采用内置R程序对GEO(Gene Expression Omnibus)数据库中4项原发性肝癌临床研...目的:验证G2/S期应答相关蛋白1(G2 and S phase-expressed protein 1,GTSE1)在原发性肝癌组织及细胞株中高表达,并探讨其表达下调对肝癌细胞凋亡的影响。方法:采用内置R程序对GEO(Gene Expression Omnibus)数据库中4项原发性肝癌临床研究的基因表达矩阵数据进行分析,筛选肝癌与癌旁组织差异表达基因。采用蛋白质印迹法验证3例肝癌组织和3株肝癌细胞中GTSE1蛋白表达水平。向肝癌Hep-G2和Bel-7402细胞中分别转染GTSE1 siRNA后,采用CCK-8和FCM法分别检测GTSE1表达下调对肝癌细胞增殖、凋亡及5-氟尿嘧啶(5-fluorouracil,5-FU)敏感性的影响,进一步采用蛋白质印迹法检测p53含量及其亚细胞定位,以及Bcl-2家族成员的表达变化。结果:4项研究中原发性肝癌组织表达水平均上调和下调的基因分别为51和146个。其中,上调基因产物GTSE1蛋白在3例临床肝癌组织标本和3株肝癌细胞Hep-G2、Bel-7402和SMMC-7721中均得到进一步验证(P值均<0.001)。siRNA转染后,肝癌Hep-G2和Bel-7402细胞中GTSE1基因沉默效率>70%。与对照组相比,GTSE1表达下调后肝癌Hep-G2和Bel-7402细胞增殖被明显抑制,并随着时间延长,抑制作用逐渐增强(P值均<0.05);GTSE1表达下调后肝癌Hep-G2和Bel-7402细胞周期被阻滞在G1期,同时细胞凋亡率明显升高,且细胞对5-FU的敏感性明显增强(P值均<0.01)。GTSE1表达下调后的肝癌Hep-G2和Bel-7402细胞中总p53及磷酸化P53表达水平均明显上调(P值均<0.05),且细胞核内p53水平升高(P值均<0.01);Bcl-2家族促凋亡成员Bax和Bak表达水平均上调,而抗凋亡成员Bcl-2表达水平下调(P值均<0.05)。结论:下调肝癌中GTSE1蛋白表达能通过活化p53通路促进细胞凋亡,并增加肝癌细胞对化疗药物的敏感性。展开更多
文摘Criegee intermediate is believed to play an important role in the atmospheric chemistry.Because of its short life and the difficulty in experimental study, we carried out ah initio calculations on the thermochemistry of the Criegee involving reactions in this study. Thermochemistrydata of reaction enthalpies and Gibbs free energies for four different stable structures of the Criegeeintermediates (singlet CH2OO ①1 A1 in C2v, triplet CH2OO ②3B1 in C2v, singlet CH2OO ③1A’ in Cs and triplet CH2OO ④ in C1 symmetry) involved in some of the gas-phase reactions were calculated at the standard Gaussian-2 [G2(MP2) and G2] and a modified G2, G2(fu1)[10],levels of theory. Relative energies among those Criegees and formic acid were compared. Chemical reactions incltlde the formation of Criegees, re-arrangement from Criegee to formic acid, dissociations (producing CH2(3B1)+O2, CH2(1A1)+O2, CO2+H2, CO2+2H, CO+H2O, OH+HCO) andthe reactions between Criegee and NO/H2O. Standard equilibrium constants for some reactions were investigated and may be obtained for all of the rest reactions involved in this study by the standard Gibbs free energies. It is shown that the formation of Criegee①-④ by ethylene and ozone, the re-arrangement from any Criegee to formic acid, the dissociation in producing CO2+O2and CO+H2O and the reactions between any Criegee and NO/H2O are all favourable thermodynamicaly. The dissociation in forming CO2+2H and OH+HCO is less favourable. While the dissociation in forming carbene (either in 3B1 or 1A1 state) is not allowed by values. Standard enthalpies of formation at 298 K for the four Criegees were predicted at the G2(ful) level of theory. Each value is the average value from ten of the above reactions and they are -4.3, 74.8,98.9 and 244.6 kJ mol-1 at the G2(ful) level for Criegee ① to Criegee ④, respectively. In addition, tile standard enthalpy of formation at 298 K for HOCH2OOH is further predicted to be -315.6 kJ mol-1 at the G2(MP2) level.
文摘目的:验证G2/S期应答相关蛋白1(G2 and S phase-expressed protein 1,GTSE1)在原发性肝癌组织及细胞株中高表达,并探讨其表达下调对肝癌细胞凋亡的影响。方法:采用内置R程序对GEO(Gene Expression Omnibus)数据库中4项原发性肝癌临床研究的基因表达矩阵数据进行分析,筛选肝癌与癌旁组织差异表达基因。采用蛋白质印迹法验证3例肝癌组织和3株肝癌细胞中GTSE1蛋白表达水平。向肝癌Hep-G2和Bel-7402细胞中分别转染GTSE1 siRNA后,采用CCK-8和FCM法分别检测GTSE1表达下调对肝癌细胞增殖、凋亡及5-氟尿嘧啶(5-fluorouracil,5-FU)敏感性的影响,进一步采用蛋白质印迹法检测p53含量及其亚细胞定位,以及Bcl-2家族成员的表达变化。结果:4项研究中原发性肝癌组织表达水平均上调和下调的基因分别为51和146个。其中,上调基因产物GTSE1蛋白在3例临床肝癌组织标本和3株肝癌细胞Hep-G2、Bel-7402和SMMC-7721中均得到进一步验证(P值均<0.001)。siRNA转染后,肝癌Hep-G2和Bel-7402细胞中GTSE1基因沉默效率>70%。与对照组相比,GTSE1表达下调后肝癌Hep-G2和Bel-7402细胞增殖被明显抑制,并随着时间延长,抑制作用逐渐增强(P值均<0.05);GTSE1表达下调后肝癌Hep-G2和Bel-7402细胞周期被阻滞在G1期,同时细胞凋亡率明显升高,且细胞对5-FU的敏感性明显增强(P值均<0.01)。GTSE1表达下调后的肝癌Hep-G2和Bel-7402细胞中总p53及磷酸化P53表达水平均明显上调(P值均<0.05),且细胞核内p53水平升高(P值均<0.01);Bcl-2家族促凋亡成员Bax和Bak表达水平均上调,而抗凋亡成员Bcl-2表达水平下调(P值均<0.05)。结论:下调肝癌中GTSE1蛋白表达能通过活化p53通路促进细胞凋亡,并增加肝癌细胞对化疗药物的敏感性。
