To study the mechanism of infection of Epstein-Barr virus (EBV) in gastric carcinoma cells, the Akata and P3HR-1 strains of EBV were used as the test strains of viruses, and the signet ring cell line HSC-39 of gastric...To study the mechanism of infection of Epstein-Barr virus (EBV) in gastric carcinoma cells, the Akata and P3HR-1 strains of EBV were used as the test strains of viruses, and the signet ring cell line HSC-39 of gastric carcinoma cells was used as the target cells of infection. The virus-infected cell clones were isolated by limited dilution method. It was found that the EBV-encoded small RNA (EBER) could be detected in the infected cells. The Akata and P3HR-1 EBV infected parental cells and most of clones expressed EBNA1, but not EBNA2. Latent membrane protein (LMP-1) and LMP-2, and the Q promoter (p), but not the Cp/Wp for EBNA gene transcription was active in the infected parental cells as well as all the clones. Uninfected HSC-39 cells did not express CD21, however, Akata but not P3HR-1 EBV-infected clones expressed low level of CD21 mRNA. These results demonstrate that HSC-39 cells are susceptible to both EBV strains and EBV infects HSC-39 cells through the CD21-independent pathway. This study defines a signet ring type of gastric carcinoma cells line as a unique target cells for the study of EBV infection mechanism.展开更多
The effects of two antisense oligodeoxynucleotides on the expression of c-Ha-ras proto-oncogene and the growth of human gastric carcinoma cell lines were observed. Synthetic 15-mer directed at the region of the transl...The effects of two antisense oligodeoxynucleotides on the expression of c-Ha-ras proto-oncogene and the growth of human gastric carcinoma cell lines were observed. Synthetic 15-mer directed at the region of the translational initiation site of c-Ha-ras proto-oncogene (ASO-r) greatly inhibited the proliferation (55. 61%,P<0. 05) and DNA synthesis (76. 79%,P<0. 05) of MGc-803 cell line. It also inhibited the proliferation (62. 02%,P<0. 05) and DNA synthesis (76. 78%, P<0. 05) of SGc-7901 cell line. A reduction in intracellular P21 ras protein levels in MGc-803 cell line was observed 6 h after the treatment with ASO-r and maintained over 12 h. Another synthetic 15-mer targeted against the initiation codon and downstream 4 codons of c-myc proto-oncogene (ASOm) inhibited only DNA synthesis of MGc-803 cell line (71. 37%, P<0. 05). The control 15-mer did not inhibit the expression of P21 protein and proliferation of these cell lines. These experiments seemed to provide evidence that ASO-r could be effective in inhibiting the expression of c-Ha-ras proto-oncogene and controlling the growth of human gastric carcinoma cells,and that the over-expression of c-Ha-ras proto-oncogene might mainly be associated with the malignant proliferation of human gastric carcinoma cells.展开更多
目的探讨miR-21在肾透明细胞癌中的表达及其临床意义,以及如何通过调节程序性细胞死亡因子4(programmed cell death 4,PDCD4)的表达影响786-O肾透明细胞癌细胞系的增殖和凋亡。方法通过分析The Cancer Genome Atlas(TCGA)肾透明细胞癌...目的探讨miR-21在肾透明细胞癌中的表达及其临床意义,以及如何通过调节程序性细胞死亡因子4(programmed cell death 4,PDCD4)的表达影响786-O肾透明细胞癌细胞系的增殖和凋亡。方法通过分析The Cancer Genome Atlas(TCGA)肾透明细胞癌数据库,比较癌组织及正常癌旁组织中miR-21的表达水平;分析miR-21表达水平在不同临床病理分期肾癌组织中的差异;采用Kaplan-Meier法和对数秩和检验(Log-rank test)研究miR-21表达水平和患者生存之间的关系;通过转染miR-21抑制性核苷酸(AS-miR-21)下调miR-21表达水平,采用MTT和流式细胞术分别检测细胞增殖和凋亡,采用实时定量PCR(qRT-PCR)和Western blot测量PDCD4mRNA和蛋白质表达水平变化,采用双荧光素报告系统检测miR-21对PDCD4的直接调节。结果肾透明细胞癌组织中miR-21的表达水平显著高于癌旁组织(P<0.000 1)。miR-21在Ⅲ期和Ⅳ期肾癌组织中表达水平显著高于Ⅰ期(P均<0.000 1),miR-21表达水平与临床病理分期呈正相关(r=0.262,P<0.000 1)。miR-21表达水平与T分期(r=0.250,P<0.000 1)与淋巴结转移阳性(N1)以及远处转移均呈正相关(P均<0.001)。生存分析显示miR-21高表达患者中位生存时间显著短于miR-21低表达者中位生存时间(Log-rank,P<0.001)。下调miR-21后,786-O细胞的增殖能力较对照显著降低(P<0.05),凋亡显著增加(P=0.005),PDCD4mRNA(P=0.002)和蛋白质表达水平显著增高。双荧光素报告实验显示在转染AS-miR-21的细胞内PDCD4相对荧光强度较对照细胞显著升高(P=0.003)。结论 miR-21在肾透明细胞癌组织中表达升高,与患者临床病理分期呈正相关,和患者生存呈负相关;miR-21可能通过调节PDCD4表达水平,参与调节肾透明细胞癌细胞的增殖和凋亡。展开更多
文摘To study the mechanism of infection of Epstein-Barr virus (EBV) in gastric carcinoma cells, the Akata and P3HR-1 strains of EBV were used as the test strains of viruses, and the signet ring cell line HSC-39 of gastric carcinoma cells was used as the target cells of infection. The virus-infected cell clones were isolated by limited dilution method. It was found that the EBV-encoded small RNA (EBER) could be detected in the infected cells. The Akata and P3HR-1 EBV infected parental cells and most of clones expressed EBNA1, but not EBNA2. Latent membrane protein (LMP-1) and LMP-2, and the Q promoter (p), but not the Cp/Wp for EBNA gene transcription was active in the infected parental cells as well as all the clones. Uninfected HSC-39 cells did not express CD21, however, Akata but not P3HR-1 EBV-infected clones expressed low level of CD21 mRNA. These results demonstrate that HSC-39 cells are susceptible to both EBV strains and EBV infects HSC-39 cells through the CD21-independent pathway. This study defines a signet ring type of gastric carcinoma cells line as a unique target cells for the study of EBV infection mechanism.
文摘The effects of two antisense oligodeoxynucleotides on the expression of c-Ha-ras proto-oncogene and the growth of human gastric carcinoma cell lines were observed. Synthetic 15-mer directed at the region of the translational initiation site of c-Ha-ras proto-oncogene (ASO-r) greatly inhibited the proliferation (55. 61%,P<0. 05) and DNA synthesis (76. 79%,P<0. 05) of MGc-803 cell line. It also inhibited the proliferation (62. 02%,P<0. 05) and DNA synthesis (76. 78%, P<0. 05) of SGc-7901 cell line. A reduction in intracellular P21 ras protein levels in MGc-803 cell line was observed 6 h after the treatment with ASO-r and maintained over 12 h. Another synthetic 15-mer targeted against the initiation codon and downstream 4 codons of c-myc proto-oncogene (ASOm) inhibited only DNA synthesis of MGc-803 cell line (71. 37%, P<0. 05). The control 15-mer did not inhibit the expression of P21 protein and proliferation of these cell lines. These experiments seemed to provide evidence that ASO-r could be effective in inhibiting the expression of c-Ha-ras proto-oncogene and controlling the growth of human gastric carcinoma cells,and that the over-expression of c-Ha-ras proto-oncogene might mainly be associated with the malignant proliferation of human gastric carcinoma cells.
文摘肝脏是代谢的中枢性器官,在糖脂代谢中扮演重要角色。FGF-21是近年来发现的一种治疗糖尿病新型药物,研究其对肝脏糖代谢影响及机制将为FGF-21成药性提供理论依据。以Hep G2细胞为肝细胞模型,探究FGF-21对Hep G2细胞葡萄糖吸收影响及作用机制。FGF-21处理Hep G2细胞,采用葡萄糖氧化酶-过氧化物酶(GOD-POD)法检测细胞对葡萄糖摄取情况,并检查胰岛素与FGF-21协同作用,蒽酮法检测细胞内糖原含量,半定量和实时荧光定量PCR检测FGF-21对葡萄糖转运蛋白(GLUTs)m RNA表达影响。结果表明,FGF-21可促进Hep G2细胞摄取葡萄糖,与胰岛素具有一定协同作用,增加糖原合成。半定量PCR结果显示在FGF-21作用下,仅GLUT1m RNA表达有所增加。实时荧光定量PCR检测FGF-21作用时间对GLUT1 m RNA表达量影响,发现FGF-21作用6 h时GLUT1 m RNA表达量倍数增加最大。说明FGF-21可通过增加GLUT1 m RNA表达促进Hep G2细胞消耗葡萄糖,参与糖原合成。
