Genes regulated in human breast cancer cells overexpressing manganese-containing superoxide dismutase

Citation
Zk. Li et al., Genes regulated in human breast cancer cells overexpressing manganese-containing superoxide dismutase, FREE RAD B, 30(3), 2001, pp. 260-267
Citations number
34
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biochemistry & Biophysics
Journal title
FREE RADICAL BIOLOGY AND MEDICINE
ISSN journal
0891-5849 → ACNP
Volume
30
Issue
3
Year of publication
2001
Pages
260 - 267
Database
ISI
SICI code
0891-5849(20010201)30:3<260:GRIHBC>2.0.ZU;2-M
Abstract
The mitochondrial antioxidant enzyme manganese-containing superoxide dismut ase (MnSOD) functions as a tumor suppressor gene. Reconstitution of MnSOD e xpression in several human cancer cell lines leads to reversion of malignan cy and induces a resistant phenotype to the cytotoxic effects of TNF and hy perthermia. The signaling pathways that underlie these phenotypic changes i n MnSOD-overexpressing cells are unknown, although alterations in the activ ity of several redox-sensitive transcription factors, including AP-1 and NF -kappaB, have been observed. To determine the downstream signaling molecule s involved in MnSOD-induced cell resistant phenotype, in the present study we analyzed the expression profile of several groups of genes related to st ress response, DNA repair, and apoptosis, in a human breast cancer MCF-7 ce ll line overexpressing MnSOD (MCF+SOD). Of 588 genes examined, 5 (0.85%) we re up-regulated (2-42-fold), and 11 (1.9%) were down-regulated (2-33-fold) in the MCF + SOD cells compared to the parental MCF-7 cells. The five up-re gulated genes were MET, GADD153, CD9, alpha -catenin and plakoglobin. The g enes with the most significant down-regulation included: vascular endotheli al growth factor receptor 1, TNF-alpha converting enzyme, and interleulin-1 beta. GADD153 (involved in the repair of DNA double strand breaks) showed a 33-fold increase in microarray analysis and these results were confirmed by RT-PCR. To further determine the specificity in MnSOD-induced gene regul ation, MCF+SOD cells were stably transfected with an antisense MnSOD sequen ce whose expression was controlled by a tetracycline inducible regulator. E xpression of three up-regulated genes was measured after induction of antis ense MnSOD expression. Interestingly, expression level of GADD153 but not M ET or CD9 was reduced 24 h after antisense MnSOD induction. Together, these results suggest that reconstitution of MnSOD in tumor cells can specifical ly modulate the expression of down-stream effector genes. GADD153 and other elements observed in the MCF + SOD cells may play a key role in signaling the MnSOD-induced cell phenotypic change. (C) 2001 Elsevier Science Inc.