Topotecan hydrochloride

Chemicals purchased from Cayman Chemical (Ann Arbor, MI) include 5-azacytidine, Bay 11-7085, camptothecin, D-ribofuranosylbenzimidazole, H-8 HCl, kenpaullone, 3,4-Methylenedioxy-β-nitrostyrene (MNS), niclosamide, PD 98059, and topotecan hydrochloride. Citral, DMSO, LY-294002, retinol, and SU 4312 were purchased from Sigma-Aldrich (St. Louis, MO). CD437, ER50891, HX531, and SR11237 were purchased from Torcris (Minneapolis, MN). AM580 was purchased from Enzo Life Sciences (Farmingdale, NY). Chemicals were prepared as stock solution aliquots in DMSO and stored in the vapor phase of liquid nitrogen. Chemicals were protected from extended exposure to light when being prepared and used in assays. The LOPAC was purchased from Sigma-Aldrich and stored following the protocols at the National Center for Advancing Translational Sciences (NCATS) ^{22 (link)}. The Cignal lentiviral reagent, which had a lentivirus concentration of 1.7 × 10⁷ transducing units (TU)/ml, was obtained from SABiosciences (Qiagen, Frederick, MD). The MTT cell viability assay kit was obtained from ATCC (Manassas, VA) and used following the manufacturer's instructions.

Camptothecin was a gift of the Drug Synthesis and Chemistry Branch, Developmental Therapeutic Program of NCI, NIH. Topotecan hydrochloride was obtained from Cayman Chemicals (Ann Arbor, MI). A stock solution of camptothecin was prepared in DMSO, TPT was dissolved in doubly distilled water, and solutions were stored at −80°C. Ascorbic acid and horseradish peroxidase (HRP) were obtained from Sigma-Aldrich Chemical Company (St. Louis, MO). Ascorbic acid (100 mM) was dissolved in chelex-treated phosphate buffer and the pH of the solution was adjusted to 7.2 and stored at −80°C. Human myeloperoxidase was purchased from Lee Biosolutions (St. Louis, MO). Human topo I, antibody to Human topo I, and SDS/KCl precipitation assay kits were obtained from Topogen (Buena Vista, CO). Primary antibody for the analysis of p53 was obtained from Santa Cruz Biochemicals (Dallas, TX). Primary antibody anti-gamma H2AX, for the detection of DNA double-strand breaks, anti-p21, and anti-β-actin were obtained from Abcam (Cambridge, MA). DMPO was purchased from Dojindo (Rockville, MD) and used without any further purification.