Inhibition of Telomerase Activity Using an EGFP-Intron Splicing System Encoding Multiple RNAi Sequences.

To inhibit telomerase activity, a construct which contains artificial introns in the enhanced green fluorescent protein (EGFP) gene that encodes small hairpin RNA (shRNA) sequences that target human telomerase reverse transcriptase (hTERT) gene expression was designed and tested for its effect on lung cancer cell line. On intron splicing from the construct, intronic sequences were released and formed shRNA in the cells. After transfection of the construct, hTERT mRNA expression decreased by approximately 55 % in A549 cells. Correspondingly, in the same cell line, telomerase activity was decreased by approximately 23 %. The telomerase activity was transiently inhibited by this non-viral shRNA expression system that uses intron splicing to release artificial introns in an EGFP marker gene that contain shRNA targeting telomerase.