TELOMERASE ASSOCIATED FACTORS AND THEIR ROLES IN CANCER PROGRESSION

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。癌细胞通常上调核糖核蛋白-端粒酶。抑制端粒酶此前被预测可以减缓癌症的生长，但只有在端粒缩短发生的足够时间之后。最近，我们通过针对野生型端粒酶RNA模板区域的siRNA抑制了端粒酶功能，从而特异性地抑制了癌细胞的生长。这种siRNA在癌细胞中的表达导致端粒酶活性显著降低，迅速抑制细胞生长并诱导细胞凋亡。出乎意料的是，这些强大的细胞效应并不是由端粒结构的破坏引起的，这表明siRNA抑制端粒酶可能抑制了癌细胞中端粒酶的一种功能，而不是维持端粒长度。这些细胞中的DNA微阵列分析表明，与生长相关的基因表达迅速变化，这与双链RNA引发的干扰素反应无关。这些数据表明，除了维持端粒长度外，端粒酶对癌细胞的增殖可能也是必不可少的。因此，我们研究的一个主要重点是通过鉴定新的端粒酶相关因子来进一步了解端粒酶调节细胞增殖的潜在机制。采用串联亲和纯化(TAP)技术实现了人癌细胞株Hela S3端粒酶复合体的生化纯化。与端粒酶相关的蛋白质将通过质谱学进行分离和鉴定。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Cancer cells commonly upregulate the ribonucleoprotein-telomerase. Inhibition of telomerase has previously been predicted to slow cancer growth, but only after a sufficient period elapses for telomere shortening to occur. Recently, we have inhibited cancer cell growth specifically by inhibiting telomerase function through an siRNA targeting the template region of wild-type telomerase RNA. Expression of such siRNA in cancer cells resulted in dramatic reduction of telomerase activity, rapid inhibition of cell growth and induction of apoptosis. Unexpectedly, those potent cellular effects were not apparently induced by the disruption of telomere structures, suggesting that inhibition of telomerase by siRNA may inhibit a function of telomerase in cancer cells other than telomere length maintenance. DNA microarray analysis in these cells indicates rapid changes in growth-related gene expression that is independent of interferon response triggered by double stranded RNA. These data suggested that telomerase may be essential for cancer cell proliferation in addition to telomere length maintenance. Therefore, a main focus of our research is to further understand the underlying mechanisms by which telomerase regulates cell proliferation through identification of novel telomerase associated factors. Biochemistry purification of telomerase complexes from human cancer cell line Hela S3 has been achieved using Tandem affinity purification (TAP) protocol. Proteins associated specifically with telomerase will be isolated and identified by Mass Spectrometry.