title: JS-K, a nitric oxide-releasing prodrug, induces breast cancer cell death while sparing normal mammary epithelial cells.
abstract: Targeted therapy with reduced side effects is a major goal in cancer research. We investigated the effects of JS-K, a nitric oxide (NO) prodrug designed to release high levels of NO when suitably activated, on human breast cancer cell lines, on non-transformed human MCF-10A mammary cells, and on normal human mammary epithelial cells (HMECs). Cell viability assay, flow cytometry, electron microscopy, and Western blot analysis were used to study the effects of JS-K on breast cancer and on mammary epithelial cells. After a 3-day incubation, the IC50s of JS-K against the breast cancer cells ranged from 0.8 to 3 µM. However, JS-K decreased the viability of the MCF-10A cells by only 20% at 10-µM concentration, and HMECs were unaffected by 10 µM JS-K. Flow cytometry indicated that JS-K increased the percentages of breast cancer cells under-going apoptosis. Interestingly, flow cytometry indicated that JS-K increased acidic vesicle organelle formation in breast cancer cells, suggesting that JS-K induced autophagy in breast cancer cells. Electron microscopy confirmed that JS-K-treated breast cancer cells underwent autophagic cell death. Western blot analysis showed that JS-K induced the expression of microtubule light chain 3-II, another autophagy marker, in breast cancer cells. However, JS-K did not induce apoptosis or autophagy in normal human mammary epithelial cells. These data indicate that JS-K selectively induces programmed cell death in breast cancer cells while sparing normal mammary epithelial cells under the same conditions. The selective anti-tumor activity of JS-K warrants its further investigation in breast tumors.
authors.affiliation: Department of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Vanity
authors.initials: V
authors.lastname: McMurtry
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Saavedra
authors.forename: René
authors.initials: R
authors.lastname: Nieves-Alicea
authors.forename: Ann-Marie
authors.initials: AM
authors.lastname: Simeone
authors.forename: Larry K
authors.initials: LK
authors.lastname: Keefer
authors.forename: Ana M
authors.initials: AM
authors.lastname: Tari
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D001391:Azo Compounds / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000473:pathology*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D005260:Female; D051547:Heme Oxygenase-1 / Q000378:metabolism; D006801:Humans; D042361:Mammary Glands, Human / Q000187:drug effects* / Q000473:pathology; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D010879:Piperazines / Q000494:pharmacology*; D011355:Prodrugs / Q000494:pharmacology*; D015854:Up-Regulation
chemical_list: D000970:Antineoplastic Agents; D001391:Azo Compounds; C477012:MAP1LC3A protein, human; D008869:Microtubule-Associated Proteins; C474958:O(2)-(2,4-dinitrophenyl) 1-((4-ethoxycarbonyl)piperazin-1-yl)diazen-1-ium-1,2-diolate; D010879:Piperazines; D011355:Prodrugs; D009569:Nitric Oxide; D051547:Heme Oxygenase-1