Small molecule telomerase inhibitors are also potent inhibitors of telomeric C-strand synthesis

Inhibition of CST–PP activity by TMPyP4. (A) Representative gels showing C-strand synthesis on the 9xTEL template in NaCl/KCl (left) or LiCl (right) with trace amount of radiolabeled template (T) serving as recovery control. Twofold dilutions of TMPyP4 (highest concentration: 3200 nM) were incubated with the template before the addition of CST–PP and nucleotides. (B) Plot of relative synthesis intensities as a function of TMPyP4 concentration in NaCl/KCl or LiCl. Points represent mean values and error bars represent SD for n = 5 (Na⁺/K⁺) or n = 4 (Li⁺) independent experiments. (C,D) Same as panels A,B except that the template was 9xnoGG. For panel D, n = 4.