Idt scitools

All synthetic RNA and DNA were ordered from Integrated DNA Technologies (Coralville, Iowa), and were certified by the manufacturer by mass spectrometry and provided desalted. PITX1_1901-1930 RNA (Q2RNA) and PITX1_1901-1930 DNA (Q2DNA) were dissolved in 10 mM Tris (pH 7.5), 100 mM KCl, 1 mM EDTA at a concentration of 5 μM. Samples were heated to 95°C for 5 min and cooled slowly to room temperature to form G4. Nucleic acid in conformations other than G4 were then removed by size exclusion chromatography (SEC) on a HiLoad Superdex 75 26/60 in 10 mM Tris (pH 7.5), 100 mM KCl, and 1 mM EDTA (ÄKTA, GE Healthcare) as described previously (5 mL load volume) [42 (link)]. Sample purity was confirmed by both native and denaturing gel electrophoresis separately (15% native or denaturing Tris/Borate/EDTA polyacrylamide gels using urea as a denaturant). Quadruplex-forming nucleic acids were detected with N-methyl mesoporphyrin IX (NMM) staining (Frontier Scientific, Logan, UT, USA). Extinction coefficients (260 nm) were calculated from the sequence using IDT SciTools (OligoAnalyzer3.1, Integrated DNA Technologies) and corrected for hyperchromicity using the absorption spectra at 20°C and 90°C: Q2RNA, 253550 M^-1cm^-1; Q2DNA 264200 M^-1cm^-1.

Paclitaxel was purchased from Sigma (St. Louis, MO). Specific primers were designed using the Real-Time PCR web tool from IDT SciTools (Integrated DNA Technologies, Coralville, IA).