Figure 1: Novel Therapies Targeting Telomeres and Telomerase. The single stranded 3’ telomere overhang folds over itself and invades the double stranded region, forming a t-loop. This process is aided by a six-protein complex called shelterin, which caps telomere ends and regulates telomerase. G-quadruplexes are formed by stabilizing hydrogen bond interactions facilitated by the guanine rich character of the 3’ overhang. Increasing G-quadruplex stability can consequently inhibit telomerase. TNKS1 poly(ADP-ribosyl)ates TRF1, thereby releasing it from the telomere and allowing telomerase access to the 3’ overhang. Inhibiting TNKS1 is thought to prevent poly(ADP-ribosyl)ation of TRF1 and hence inhibits telomerase activity. T-oligo has sequence homology with the 3’ telomere overhang. T-oligo administration is thought to mimic telomere exposure and induce anticancer responses, mainly in cancer cells with minimal effects in normal cells.