title: A light-activated NO donor attenuates anchorage independent growth of cancer cells: Important role of a cross talk between NO and other reactive oxygen species.
abstract: It is established that high concentrations of nitric oxide(1) (NO), as released from activated macrophages, induce apoptosis in breast cancer cells. In this study, we assessed the potential of a light-activated NO donor [(Me2bpb)Ru(NO)(Resf)], a recently reported apoptototic agent, in suppressing the anchorage independent growth potentials of an aggressive human breast cancer cell line. Our results demonstrated the down regulation of anchorage independent growth by light activated NO treatment in the aggressive human breast cancer cell line MDA-MB-231 and afforded insight into the associated mechanism(s). The investigation revealed an up-regulation of the bioactivity of catalase with an accompanied reduction in the endogenous levels of H2O2, a direct substrate of catalase and a recently identified endogenous growth modulator in breast cancer cells. An earlier publication reported that endogenous superoxide (O2(-)) in human breast cancer cells constitutively inhibits catalase bioactivity (at the level of its protein), resulting in increased H2O2 levels. Interestingly in this study, O2(-) was also found to be down- regulated following NO treatment providing a basis for the observed increase in catalase bioactivity. Cells silenced for the catalase gene exhibited compromised reduction in anchorage independent growth upon light activated NO treatment. Collectively this study detailed a mechanistic cross talk between exogenous NO and endogenous ROS in attenuating anchorage independent growth.
authors.affiliation: Department of Obstetrics and Gynecology, David Geffen School of Medicine at University of California at Los Angeles, Los Angeles, CA 90095, USA. Electronic address: ssen@mednet.ucla.edu.
authors.forename: Suvajit
authors.initials: S
authors.lastname: Sen
authors.forename: Brian
authors.initials: B
authors.lastname: Kawahara
authors.forename: Nicole L
authors.initials: NL
authors.lastname: Fry
authors.forename: Robin
authors.initials: R
authors.lastname: Farias-Eisner
authors.forename: Dalia
authors.initials: D
authors.lastname: Zhang
authors.forename: Pradip K
authors.initials: PK
authors.lastname: Mascharak
authors.forename: Gautam
authors.initials: G
authors.lastname: Chaudhuri
mesh_terms: D001943:Breast Neoplasms / Q000473:pathology; D002374:Catalase / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects / Q000528:radiation effects; D003114:Colony-Forming Units Assay; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008027:Light; D009569:Nitric Oxide / Q000737:chemistry / Q000378:metabolism*; D009942:Organometallic Compounds / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects / Q000528:radiation effects; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism*; D014443:Tyrosine / Q000031:analogs & derivatives / Q000096:biosynthesis
chemical_list: D009942:Organometallic Compounds; D013481:Superoxides; D009569:Nitric Oxide; C002744:3-nitrotyrosine; D014443:Tyrosine; D006861:Hydrogen Peroxide; D002374:Catalase; D013482:Superoxide Dismutase; D051057:Proto-Oncogene Proteins c-akt
keywords: Anchorage independent growth; Breast cancer; Catalase; Nitric oxide; [(Me(2)bpb)Ru(NO)(Resf)]