人肺癌细胞的肿胀应激及其信号通路分析

目的 通过比较肺癌与对应癌旁组织的含水量、细胞核大小以及丝裂原激活蛋白激酶(MAPK)磷酸化激活情况以明确肺癌细胞是否存在肿胀应激。方法 采用干湿质量比较法检测10例人肺腺癌、 12例肺鳞癌以及对应的癌旁正常肺组织新鲜标本的含水量差别。用磷酸化和非磷酸化抗体结合免疫组织化学染色方法,检测30例肺腺癌、 32例肺鳞癌、 10例正常肺泡上皮细胞和10例正常肺支气管上皮细胞c-Jun氨基末端激酶(JNK)、胞外信号调节激酶1/2(ERK1/2)和p38 MAPK的表达及磷酸化激活情况。最后采用HE染色结合图像分析软件估算肺腺癌和肺鳞癌的癌细胞和对应癌旁正常肺泡上皮细胞及支气管上皮细胞的细胞核大小差别。结果 干湿质量比较法发现肺鳞癌和肺腺癌的平均含水量均显著高于其对应的癌旁正常组织。免疫组织化学染色发现p38 MAPK在肺腺癌和肺鳞癌及癌旁组织均高表达。ERK在肺腺癌和鳞癌组织均弱表达,但是在肺癌旁组织高表达。JNK在肺腺癌及癌旁组织均弱表达。在肺泡上皮组织和支气管上皮组织中JNK、 p38 MAPK、 ERK1/2均未被磷酸化激活。但是,肺腺癌、肺鳞癌组织中JNK被磷酸化激活,而p38 MA...     

Expression and Subcellular Localization of Recombinant SDF-1 and Its Mutant Intrakine in Transfected COS-7 Cells

INTRODUCTION The CXC chemokine stromal cell -derived factor1(SDF-1) , a member of CXC-chemokine family,is the ligand for CXCR4 and binds CXCR4 with high affinity.The interaction of SDF-1 and CXCR4 mayinduce cytoskeletal rearrangement, adhesive to endothelial cells and directional migration. SDF-1 bind-ing to CXCR4 can activiate multiple signaling pathways and produce different physiology or pathologyeffects. Compelling evidence is accumulating HIV infection and tumor metastas…     

Fungiform papilla pattern: EGF regulates inter-papilla lingual epithelium and decreases papilla number by means of PI3K/Akt, MEK/ERK, and p38 MAPK signaling

Fungiform papillae are epithelial taste organs that form on the tongue, requiring differentiation of papillae and inter-papilla epithelium. We tested roles of epidermal growth factor (EGF) and the receptor EGFR in papilla development. Developmentally, EGF was localized within and between papillae whereas EGFR was progressively restricted to inter-papilla epithelium. In tongue cultures, EGF decreased papillae and increased cell proliferation in inter-papilla epithelium in a concentration-dependent manner, whereas EGFR inhibitor increased and fused papillae. EGF preincubation could over-ride disruption of Shh signaling that ordinarily would effect a doubling of fungiform papillae. With EGF-induced activation of EGFR, we demonstrated phosphorylation in PI3K/Akt, MEK/ERK, and p38 MAPK pathways; with pathway inhibitors (LY294002, U0126, SB203580) the EGF-mediated decrease in papillae was reversed, and synergistic actions were shown. Thus, EGF/EGFR signaling by means of PI3K/Akt, MEK/ERK, and p38 MAPK contributes to epithelial cell proliferation between papillae; this biases against papilla differentiation and reduces numbers of papillae.     

原癌蛋白Pim-1激酶-GST融合蛋白的纯化及其激酶活性的分析

在大肠杆菌中成功表达了人原癌蛋白Pim 1激酶 GST融合蛋白 ,并对其激酶活性进行了分析。结果 :Pim 1 GST融合蛋白具有激酶活性 ,体外能使人工底物组蛋白H1发生磷酸化。其激酶活性发挥的适宜条件为pH7 5 ,10mmol/LMgCl2 的反应体系。过高的离子浓度和过高或过低的pH值均抑制其激酶活性的发挥。     

Hemin诱导K562细胞分化前后PU.1全基因组结合位点探测

目的 探讨K562细胞分化前后全基因组上的PU.1结合位点图谱及靶基因.方法 用hemin对K562细胞诱导分化72 h,诱导分化前后的细胞利用PU.1抗体进行染色质免疫共沉淀实验,并进行高通量测序,利用生物信息学分析K562细胞分化前后PU.1在基因组上的结合位点,并进行基因注释、基因功能分析、KEGG通路分析及靶基...     

Analysis of the roles of E6 binding to E6TP1 and nuclear localization in the human papillomavirus type 31 life cycle

The E6 oncoproteins of high-risk human papillomaviruses provide important functions not only for malignant transformation but also in the productive viral life cycle. E6 proteins have been shown to bind to a number of cellular factors, but only a limited number of analyses have investigated the effects of these interactions on the viral life cycle. In this study, we investigated the consequences of HPV 31 E6 binding to E6TP1, a putative Rap1 GAP protein. HPV 16 E6 has been shown to bind as well as induce the rapid turnover of E6TP1, and similar effects were observed with HPV 31 E6. Mutation of amino acid 128 in HPV 31 E6 was found to abrogate the ability to bind and degrade E6TP1 but did not alter binding to another alpha-helical domain protein, E6AP. When HPV 31 genomes containing mutations at amino acid 128 were transfected into human keratinocytes, the viral DNAs were not stably maintained as episomes indicating the importance of this residue for pathogenesis. Many E6 binding partners including E6TP1 are cytoplasmic proteins, but E6 has been also reported to be localized to the nucleus. We therefore investigated the importance of E6 localization to the nucleus in the viral life cycle. Using a fusion of E6 to Green Fluorescent Protein, we mapped one component of the nuclear localization sequences to residues 121 to 124 of HPV 31 E6. Mutation of these residues in the context of the HPV 31 genome abrogated the ability for episomes to be stably maintained and impaired the ability to extend the life span of cells. These studies identify two activities of HPV 31 E6 that are important for its function in the viral life cycle and for extension of cell life span.