S1 Supporting Information Small-Molecule Inhibition of MicroRNA miR-21 Rescues Chemosensitivity of Renal Cell Carcinoma to Topotecan Yuta Naro, Nicholas Ankenbruck, Meryl Thomas, Yaniv Tivon, Colleen M. Connelly, Laura Gardner, and Alexander Deiters* Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States Contents S1-S7: Biological protocols and Supplementary Figures S7-S9: Synthesis of compound 37 S9-S18: Characterization of compounds 1-37 S19: NMR spectra and HPLC chromatogram for compound 37 S20: References Biological protocols and supplementary figures In vitro firefly luciferase inhibition assay. Recombinant firefly luciferase (Promega) was diluted to 0.24 fmol/µL in 1X PBS buffer containing DMSO (0.1% final concentration), 37 (50 µM, 0.1% DMSO), or PCT-124 (50 µM, 0.1% DMSO) in a clear-bottom, 384-well plate (Greiner) to a final volume of 50 µL. PTC-124 represents a known firefly luciferase inhibitor, 1-2 and thus was used as a positive control. The plate was incubated at room temperature for 30 min before adding 25 µL of Bright Glo reagent (Promega). The plate was then incubated on shaker for 10 minutes at room temperature before analysis for luminescence, which was measured on a microplate reader (Tecan M1000) with a measurement time of 1 s. Data was normalized to a DMSO control (Supporting Figure S1). Supporting Figure S1. In vitro firefly luciferase activity assay for 1,2,4- oxadiazole miR-21 inhibitor 37. All data was normalized to DMSO treatment (negative control) and errors bars represent standard deviations from three independent experiments. Statistical significance was determined using an unpaired t-test, ** P < 0.005, ns P > 0.05.