AbstractHuman telomerase reverse tr

Abstract

Human telomerase reverse transcriptase (hTERT) is upregulated in most cancer cell types as well in immortalized cells. The underlying mechanism for such upregulation, however, remains largely unknown. We report here that bile acids under acidified media increase hTERT expression via c-myc activation in primary human gastric cancer cell lines. Human gastric cancer MKN28, MGC803 and SGC7901 cells were treated with 100 µM deoxycholic acid (DCA) or chenodeoxycholic acid (CDCA) with or without acidified media in the presence or absence of the c-myc inhibitor 10058-F4 for 24 h. hTERT and c-myc protein levels were determined by western blot analysis. hTERT and c-myc mRNA levels were determined by RT-PCR. The promoter activities of hTERT and c-myc transcription were determined using promoter reporter luciferase assays for both. Telomerase enzyme activity was analyzed by stretch PCR. hTERT mRNA and protein levels were significantly increased by bile acids in acidified media and were accompanied with enhanced telomerase activity. No changes were found at a pH of 7.0 or with acidified media alone. Similarly, the mRNA and protein levels of c-myc were also increased by bile acids in acidified media but not at a pH of 7.0 or with acidified media alone. Importantly, pharmacologic inhibition of c-myc using 10058-F4 prevented hTERT induction by DCA or CDCA in gastric cancer cells under acidic conditions. Bile acids (DCA and CDCA) under acidic conditions increased hTERT expression in human gastric cancer cells by activation of c-myc transcription. This suggests that acidified bile acids may promote tumorigenesis and affect cell ageing via telomerase activation.

結果 (中文) 1:

摘要人端粒酶逆转录酶 (hTERT) 是在大多数癌症细胞类型以及在永生化细胞中的表达上调。然而，这种上调的底层机制仍然未知。我们在这里报告下酸化媒体胆汁酸增加通过在原发性胃癌细胞系中的 c-myc 激活端粒酶表达。人胃癌 MKN28、 MGC803 SGC7901 细胞患者 100 µ M 去氧胆酸 (DCA) 或鹅去氧胆酸 (CDCA) 有或无酸化媒体中的 c-myc 缓蚀剂 10058 f4 类 24 h.hTERT 的存在与否和 c-myc 蛋白水平测定了免疫印迹分析。hTERT 和 c-myc mRNA 水平测定 RT-pcr 技术。HTERT 和 c-myc 转录启动子活性测定使用启动子记者荧光素酶检测方法为两个。通过拉伸 PCR 分析了端粒酶活性。hTERT mRNA 和蛋白水平显著增加了在酸性介质中的胆汁酸和伴有增强端粒酶活性。均未发现变化 ph 值为 7.0 或酸化媒体与孤独。同样，c-myc 的 mRNA 和蛋白水平也被增加胆汁酸在酸性介质中，但不是能在 ph 值 7.0 或与酸化媒体单独。重要的是，c-myc 药物抑制使用 10058 F4 阻止 DCA 或 CDCA 在酸性条件下胃癌细胞端粒酶诱导。胆汁酸 (DCA 和 CDCA) 在酸性条件下增加了 c-myc 转录激活的 hTERT 在人胃癌细胞中的表达。这表明酸化的胆汁酸可能促进肿瘤的发生和影响通过端粒酶活化细胞老化。

結果 (中文) 3:

摘要

人端粒酶逆转录酶（hTERT）的表达在大多数癌症细胞类型以及在永生化细胞。这种上调的基本机制，但是，仍然在很大程度上是未知的。我们在这里报告，胆汁酸在酸性介质中通过增加hTERT的表达在原发性胃癌细胞c-myc活化。人胃癌MKN28，MGC803和SGC7901细胞在100µm脱氧胆酸（DCA）治疗或鹅去氧胆酸（CDCA）或无酸性介质中c-myc抑制剂10058-F4的存在或不存在24小时hTERT及c-myc蛋白印迹法测定蛋白质含量。hTERT和c-myc基因的RT-PCR检测mRNA的表达水平。启动子活性，hTERT和c-myc基因的启动子荧光素酶检测使用记者都确定了转录。通过拉伸聚合酶链反应分析端粒酶的活性。hTERT mRNA和蛋白水平均明显增加胆汁酸在酸性介质和带有增强端粒酶活性。在pH为7或酸化媒体单独无明显变化。同样，和c-myc的表达水平也增加了胆汁酸在酸性介质而不是在pH为7或酸化媒体单独。重要的是，应用10058-F4阻止hTERT诱导DCA或CDCA胃癌细胞在酸性条件下药物抑制c-myc。胆汁酸（DCA，CDCA）在酸性条件下增加hTERT的表达在胃癌细胞中c-myc的转录激活的。这表明，酸化胆汁酸可促进肿瘤的形成和通过激活端粒酶影响细胞老化。