TNFα induces rapid activation and nuclear translocation of telomerase in human lymphocytes

Maintenance of telomeres regulates chromosomal stability and cellular mitosis through a checkpoint mechanism. Continuous cell proliferation requires telomerase to maintain chromosomal stability and to counteract the cellular mitotic clock. Importantly, nuclear expression of telomerase activity is required for elongation of telomere sequences. In this study, we show that tumor necrosis factor α (TNFα) induces telomerase activity in the cytoplasm of peripheral blood lymphocytes (PBL) at 60 min, followed by translocation of activated telomerase to the nucleus at 120 min. Conversely, the phosphoinositol 3-kinase (PI3K) inhibitor wortmannin blocks TNFα-induced activation of telomerase, whereas the specific NF-κB translocation inhibitor SN-50 blocks TNFα-induced nuclear translocation of activated telomerase. These studies suggest that activation and nuclear translocation of telomerase are regulated by PI3K/Akt/NF-κB signaling pathways in PBL.