High-Throughput RNAi Screening Reveals Novel Regulators of Telomerase

Telomerase is considered an attractive anticancer target on the basis of its common and specific activation in most human cancers. While direct telomerase inhibition is being explored as a therapeutic strategy, alternative strategies to target regulators of telomerase that could disrupt telomere maintenance and cancer cell proliferation are not yet available. Here, we report the findings of a high-throughput functional RNA interference screen to globally profile the contribution of kinases to telomerase activity (TA). This analysis identified a number of novel telomerase modulators, including ERK8 kinase, whose inhibition reduces TA and elicited characteristics of telomere dysfunction. Given that kinases represent attractive drug targets, we addressed the therapeutic implications of our findings, such as demonstrating how limiting TA via kinase blockade could sensitize cells to inhibition of the telomere-associated protein tankyrase. Taken together, our findings suggest novel combinatorial approaches to targeting telomere maintenance as a strategy for cancer therapy. Cancer Res; 71(9); 3328-40. (C) 2011 AACR.