目的人分化抑制因子3(inhibitor of differentination 3,Id3)基因在A549细胞中的外源性表达能抑制细胞生长并诱导细胞凋亡。文中旨在构建靶向人Id3基因的微小分子RNA(miRNA)表达载体,观察miRNA对A549细胞中Id3表达的下调作用,为进一步探...目的人分化抑制因子3(inhibitor of differentination 3,Id3)基因在A549细胞中的外源性表达能抑制细胞生长并诱导细胞凋亡。文中旨在构建靶向人Id3基因的微小分子RNA(miRNA)表达载体,观察miRNA对A549细胞中Id3表达的下调作用,为进一步探讨Id3基因在A549细胞生长调控中的作用机制提供一定实验依据。方法依据miRNA设计原则,针对人Id3基因的mRNA序列,设计并合成编码miRNA的2条寡核苷酸序列,经退火成互补双链,再克隆至pcDNATM6.2-GW/EmGFP-miR真核表达载体中,构建含靶向人Id3基因的miRNA表达质粒(pcDNA6.2-GW/EmGFP-miR-Id3),DNA测序验证后,采用Lipofectamine2000TM脂质体转染技术将该质粒导入A549细胞。荧光倒置显微镜下观察miRNA干扰质粒转染A549细胞后EGFP的表达情况,应用RT-PCR和Western blot方法分别检测miRNA干扰后Id3mRNA及蛋白水平的表达。结果DNA测序表明重组质粒pcDNA6.2-GW/EmGFP-miR-Id3构建正确,将其成功导入A549细胞后,在Id3mRNA水平和蛋白表达水平均有不同程度的抑制作用。结论成功构建了针对人Id3基因的4组pcDNA6.2-GW/EmGFP-miR-Id3miRNA表达载体,其中,SRId3-1干扰组在mRNA水平和蛋白表达水平均能有效抑制A549细胞Id3的表达。展开更多
Wheat ( Triticum aestivum L.) plants were grown under ambient and doubled_CO 2(plus 350 μL/L) concentration in cylindrical open_top chamber to examine their effects on the ultrastructure, supramolecular architect...Wheat ( Triticum aestivum L.) plants were grown under ambient and doubled_CO 2(plus 350 μL/L) concentration in cylindrical open_top chamber to examine their effects on the ultrastructure, supramolecular architecture, absorption spectrum and low temperature (77 K) fluorescence emission spectrum of the chloroplasts from wheat leaves. The results were briefly summarized as follows: (1) The wheat leaves possessed normally developed chloroplasts with intact grana and stroma thylakoid membranes; The grana intertwined with stroma thylakoid membranes and increased slightly in stacking degree and the width of granum, in spite of more accumulated starch grains within the chloroplasts than those in control; (2) The particle density in the stacked region of the endoplasmic fracture face (EFs) and protoplasmic fracture face (PFs) and in the unstacked region the endoplasmic fracture face (EFu) and the protoplasmic fracture face (PFu) was significantly higher than that of control. Furthermore, in some cases many more particles on EFs faces of thylakoid membranes appeared as a paracrystalline particle array; (3) The variations in the structure of chloroplasts were consistent with the absorption spectra and the low temperature (77 K) fluorescence emission spectra of the chloroplasts developed under the doubled_CO 2 concentration. Results indicate that the capability of light energy absorption of chloroplasts and regulative capability of excitation energy distribution between PSⅡ and PSⅠ were raised by doubled_CO 2 concentration. This is very favorable for final productivity of wheat.展开更多
Using atom force microscopy (AFM), in vitro transcription, PAGE and other experimental technologies, it is observed that, in active genes of mice (Balb/c) nuclear DNA fragments of non-transcriptional state, only regul...Using atom force microscopy (AFM), in vitro transcription, PAGE and other experimental technologies, it is observed that, in active genes of mice (Balb/c) nuclear DNA fragments of non-transcriptional state, only regulation sequences at both ends are associated with scaffold proteins (indissociable proteins) and some transcriptional factors such as complexes (dissociable proteins) made of gene-coding proteins and specific auxiliary small molecules, while there are no combining proteins in intermediate coding sequences. However, in active genes of transcriptional state, both regulation sequences and intermediate coding sequences are associated with active transcriptional factors by non-covalent bonds.This paper shows the prospective application of AFM observation and in vitro transcription in the research on gene expression and regulation. It also offers some theoretical basis for localization of specific genes in human genomes.展开更多
Colorectal cancer(CRC) is the second most common cause of cancer death worldwide. Distant metastasis is the major cause of death in patients with CRC. During progression to metastasis in which malignant cells dissemin...Colorectal cancer(CRC) is the second most common cause of cancer death worldwide. Distant metastasis is the major cause of death in patients with CRC. During progression to metastasis in which malignant cells disseminate from the primary tumor to seeding other organs, a multistep process is involved. Cancer cells proliferate, invade microenvironment, enter into the blood circulation, then survive and colonize into distant organs. Micro RNAs(mi RNAs) and epithelial-mesenchymal transition(EMT) are key regulators and mechanism in tumorigenesis and cancer metastasis. We review the roles of EMT and micro RNAs, especially EMT related micro RNAs in the metastatic pathway of CRC. Micro RNAs provide us a set of potential therapeutic applications and molecular target for CRC.展开更多
文摘目的人分化抑制因子3(inhibitor of differentination 3,Id3)基因在A549细胞中的外源性表达能抑制细胞生长并诱导细胞凋亡。文中旨在构建靶向人Id3基因的微小分子RNA(miRNA)表达载体,观察miRNA对A549细胞中Id3表达的下调作用,为进一步探讨Id3基因在A549细胞生长调控中的作用机制提供一定实验依据。方法依据miRNA设计原则,针对人Id3基因的mRNA序列,设计并合成编码miRNA的2条寡核苷酸序列,经退火成互补双链,再克隆至pcDNATM6.2-GW/EmGFP-miR真核表达载体中,构建含靶向人Id3基因的miRNA表达质粒(pcDNA6.2-GW/EmGFP-miR-Id3),DNA测序验证后,采用Lipofectamine2000TM脂质体转染技术将该质粒导入A549细胞。荧光倒置显微镜下观察miRNA干扰质粒转染A549细胞后EGFP的表达情况,应用RT-PCR和Western blot方法分别检测miRNA干扰后Id3mRNA及蛋白水平的表达。结果DNA测序表明重组质粒pcDNA6.2-GW/EmGFP-miR-Id3构建正确,将其成功导入A549细胞后,在Id3mRNA水平和蛋白表达水平均有不同程度的抑制作用。结论成功构建了针对人Id3基因的4组pcDNA6.2-GW/EmGFP-miR-Id3miRNA表达载体,其中,SRId3-1干扰组在mRNA水平和蛋白表达水平均能有效抑制A549细胞Id3的表达。
文摘Wheat ( Triticum aestivum L.) plants were grown under ambient and doubled_CO 2(plus 350 μL/L) concentration in cylindrical open_top chamber to examine their effects on the ultrastructure, supramolecular architecture, absorption spectrum and low temperature (77 K) fluorescence emission spectrum of the chloroplasts from wheat leaves. The results were briefly summarized as follows: (1) The wheat leaves possessed normally developed chloroplasts with intact grana and stroma thylakoid membranes; The grana intertwined with stroma thylakoid membranes and increased slightly in stacking degree and the width of granum, in spite of more accumulated starch grains within the chloroplasts than those in control; (2) The particle density in the stacked region of the endoplasmic fracture face (EFs) and protoplasmic fracture face (PFs) and in the unstacked region the endoplasmic fracture face (EFu) and the protoplasmic fracture face (PFu) was significantly higher than that of control. Furthermore, in some cases many more particles on EFs faces of thylakoid membranes appeared as a paracrystalline particle array; (3) The variations in the structure of chloroplasts were consistent with the absorption spectra and the low temperature (77 K) fluorescence emission spectra of the chloroplasts developed under the doubled_CO 2 concentration. Results indicate that the capability of light energy absorption of chloroplasts and regulative capability of excitation energy distribution between PSⅡ and PSⅠ were raised by doubled_CO 2 concentration. This is very favorable for final productivity of wheat.
文摘Using atom force microscopy (AFM), in vitro transcription, PAGE and other experimental technologies, it is observed that, in active genes of mice (Balb/c) nuclear DNA fragments of non-transcriptional state, only regulation sequences at both ends are associated with scaffold proteins (indissociable proteins) and some transcriptional factors such as complexes (dissociable proteins) made of gene-coding proteins and specific auxiliary small molecules, while there are no combining proteins in intermediate coding sequences. However, in active genes of transcriptional state, both regulation sequences and intermediate coding sequences are associated with active transcriptional factors by non-covalent bonds.This paper shows the prospective application of AFM observation and in vitro transcription in the research on gene expression and regulation. It also offers some theoretical basis for localization of specific genes in human genomes.
基金Supported by a grant from the National Natural Sciences Foundation of China(No.81302131)Natural Science Foundation of Hubei Province,China(No.2012FKB04432)
文摘Colorectal cancer(CRC) is the second most common cause of cancer death worldwide. Distant metastasis is the major cause of death in patients with CRC. During progression to metastasis in which malignant cells disseminate from the primary tumor to seeding other organs, a multistep process is involved. Cancer cells proliferate, invade microenvironment, enter into the blood circulation, then survive and colonize into distant organs. Micro RNAs(mi RNAs) and epithelial-mesenchymal transition(EMT) are key regulators and mechanism in tumorigenesis and cancer metastasis. We review the roles of EMT and micro RNAs, especially EMT related micro RNAs in the metastatic pathway of CRC. Micro RNAs provide us a set of potential therapeutic applications and molecular target for CRC.
