Resveratrol-induced apoptosis in MCF-7 human breast cancer cells involves a caspase-independent mechanism with downregulation of Bcl-2 and NF-kappaB.
Resveratrol (RES), a chemopreventive molecule, inhibits the proliferation of tumor cells of different etiologies. We previously showed that RES alters the cell cycle and induces apoptosis in MCF-7 breast tumor cells by interfering with the estrogen receptor (ERaalpha)-dependent phosphoinositide 3-kinase (PI3K) pathway. Here, we analyzed signaling downstream of PI3K, to understand the mechanisms of RES-induced apoptosis. Apoptotic death by RES in MCF-7 was mediated by Bcl-2 downregulation since overexpression of this protein abolished apoptosis. Decreased Bcl-2 levels were not related to cytochrome c release, activation of caspases 3/8 or poly(ADP-ribose) polymerase proteolysis. However, RES decreased mitochondrial membrane potential and increased reactive oxygen species and nitric oxide production. NF-kappaB, a regulator of Bcl-2 expression, and calpain protease activity, a regulator of NF-kappaB, were both inhibited by RES. The patterns for NF-kappaB and calpain activities followed that of PI3K and were inhibited by LY294002. NF-kappaB inhibition coincided with diminished MMP-9 activity and cell migration. These data suggest that RES-induced apoptosis in MCF-7 could involve an oxidative, caspase-independent mechanism, whereby inhibition of PI3K signaling converges to Bcl-2 through NF-kappaB and calpain protease activity. Therefore, Bcl-2 and NF-kappaB could be considered potential targets for the chemopreventive activity of RES in estrogen-responsive tumor cells.
Pozo-Guisado
Eulalia
E
Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain.
Merino
Jaime M
JM
Mulero-Navarro
Sonia
S
Lorenzo-Benayas
M Jesús
MJ
Centeno
Francisco
F
Alvarez-Barrientos
Alberto
A
Fernandez-Salguero
Pedro M
PM
Salguero
Pedro M Fernandez
PM
D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017209:Apoptosis; D002154:Calpain / Q000378:metabolism; D053148:Caspase 3; D053181:Caspase 8; D020169:Caspases / Q000378:metabolism*; D002453:Cell Cycle; D045744:Cell Line, Tumor; D002465:Cell Movement; D002467:Cell Nucleus / Q000378:metabolism; D002867:Chromones / Q000494:pharmacology; D003094:Collagen / Q000737:chemistry; D045304:Cytochromes c / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004967:Estrogens / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D015151:Immunoblotting; D047468:Immunoprecipitation; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D008564:Membrane Potentials; D008928:Mitochondria / Q000378:metabolism; D008954:Models, Biological; D009025:Morpholines / Q000494:pharmacology; D016328:NF-kappa B / Q000378:metabolism*; D009573:Nitrites; D010100:Oxygen / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D017382:Reactive Oxygen Species; D000077185:Resveratrol; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D013267:Stilbenes / Q000494:pharmacology*; D013997:Time Factors
D000972:Antineoplastic Agents, Phytogenic; D002867:Chromones; D004791:Enzyme Inhibitors; D004967:Estrogens; D009025:Morpholines; D016328:NF-kappa B; D009573:Nitrites; D019253:Proto-Oncogene Proteins c-bcl-2; D017382:Reactive Oxygen Species; D013267:Stilbenes; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D003094:Collagen; D045304:Cytochromes c; D011065:Poly(ADP-ribose) Polymerases; D019869:Phosphatidylinositol 3-Kinases; C505407:CASP3 protein, human; C505530:CASP8 protein, human; D002154:Calpain; D053148:Caspase 3; D053181:Caspase 8; D020169:Caspases; D020780:Matrix Metalloproteinase 9; D000077185:Resveratrol; D010100:Oxygen