title: Part III. Molecular changes induced by high nitric oxide adaptation in human breast cancer cell line BT-20 (BT-20-HNO): a switch from aerobic to anaerobic metabolism.
abstract: Nutrient deprivation and reactive oxygen species (ROS) play an important role in breast cancer mitochondrial adaptation. Adaptations to these conditions allow cells to survive in the stressful microenvironment of the tumor bed. This study is directed at defining the consequences of High Nitric Oxide (HNO) exposure to mitochondria in human breast cancer cells. The breast cancer cell line BT-20 (parent) was adapted to HNO as previously reported, resulting in the BT-20-HNO cell line. Both cell lines were analyzed by a variety of methods including MTT, LDH leakage assay, DNA sequencing, and Western blot analysis. The LDH assay and the gene chip data showed that BT-20-HNO was more prone to use the glycolytic pathway than the parent cell line. The BT-20-HNO cells were also more resistant to the apoptotic inducing agent salinomycin, which suggests that p53 may be mutated in these cells. Polymerase chain reaction (PCR) followed by DNA sequencing of the p53 gene showed that it was, in fact, mutated at the DNA-binding site (L194F). Western blot analysis showed that p53 was significantly upregulated in these cells. These results suggest that free radicals, such as nitric oxide (NO), pressure human breast tumor cells to acquire an aggressive phenotype and resistance to apoptosis. These data collectively provide a mechanism by which the dysregulation of ROS in the mitochondria of breast cancer cells can result in DNA damage.
authors.affiliation: Universidade Federal do Rio de Janeiro, IBqM, Rio de Janeiro, Brazil.
authors.forename: H
authors.initials: H
authors.lastname: De Vitto
authors.forename: B S
authors.initials: BS
authors.lastname: Mendonça
authors.forename: K M
authors.initials: KM
authors.lastname: Elseth
authors.forename: A
authors.initials: A
authors.lastname: Onul
authors.forename: J
authors.initials: J
authors.lastname: Xue
authors.forename: B J
authors.initials: BJ
authors.lastname: Vesper
authors.forename: C V M
authors.initials: CV
authors.lastname: Gallo
authors.forename: F D
authors.initials: FD
authors.lastname: Rumjanek
authors.forename: W A
authors.initials: WA
authors.lastname: Paradise
authors.forename: J A
authors.initials: JA
authors.lastname: Radosevich
mesh_terms: D000222:Adaptation, Physiological; D000693:Anaerobiosis; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D001665:Binding Sites / Q000235:genetics; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002470:Cell Survival; D005260:Female; D018628:Gene Dosage; D015972:Gene Expression Regulation, Neoplastic; D006019:Glycolysis; D006801:Humans; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D010641:Phenotype; D011714:Pyrans / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism; D017422:Sequence Analysis, DNA; D016159:Tumor Suppressor Protein p53 / Q000235:genetics* / Q000378:metabolism; D000095662:Polyether Polyketides
chemical_list: D000900:Anti-Bacterial Agents; D009569:Nitric Oxide; D011714:Pyrans; D017382:Reactive Oxygen Species; D016159:Tumor Suppressor Protein p53; C010327:salinomycin; D000095662:Polyether Polyketides