High-throughput sequencing of an inducible CRISPR/Cas9 screen for positive regulators of hTERT transcription

Telomerase activity appears undetectable in most human somatic cells but present in ~90% of cancer and immortalized cells, underscoring the importance of upregulated telomerase activity to cancer development. Whereas telomerase RNA is highly and ubiquitously expressed even in tissues with no detectable telomerase activity, hTERT expression is exceedingly restricted in nearly all somatic cells. Transcriptional regulation is one of the most important factors for hTERT expression. To systematically search for hTERT transcriptional regulators, we performed an inducible CRISPR/Cas9 screen with a hTERT-EGFP reporter to identify positive regulators of hTERT transcription.

端粒酶（telomerase）活性在绝大多数人类体细胞中几乎无法检测，但在约90%的癌细胞与永生化细胞中均可检出，这充分凸显了端粒酶活性上调在癌症发生发展中的关键作用。尽管端粒酶RNA（telomerase RNA）即便在无端粒酶活性的组织中也呈高表达且分布广泛，但人类端粒酶逆转录酶（human telomerase reverse transcriptase, hTERT）的表达在几乎所有体细胞中均受到严格限制。转录调控是调控hTERT表达的核心因素之一。为系统性筛选hTERT的转录调控因子，我们借助hTERT-增强型绿色荧光蛋白（EGFP）报告基因开展了诱导型CRISPR/Cas9筛选实验，以鉴定hTERT转录的正向调控因子。