title: Mechanisms of naringenin-induced apoptotic cascade in cancer cells: involvement of estrogen receptor alpha and beta signalling.
abstract: The flavanone naringenin (Nar), especially abundant in the Mediterranean diet, is reported to have anti-proliferative effects in many cancer cell lines. Antioxidant activities, kinase and glucose uptake inhibition have been proposed as molecular mechanisms for these effects. In addition, an anti-estrogenic activity has been observed but, at the present, it is poorly understood whether this latter activity could play a role in the Nar anti-tumoral effects. Here, we tested the ability of Nar to activate a specific, rapid signal transduction pathway committed to the generation of an apoptotic cascade in the presence of one of the two estrogen receptor (ER) isoforms (i.e., ERalpha or ERbeta). Cancer cells containing transfected (human cervix epitheloid carcinoma HeLa cells) or endogenous ERalpha (human hepatoma HepG2 cells) or ERbeta (human colon adenocarcinoma DLD-1 cells) were used. Our results show that Nar exerts an anti-proliferative effect only in the presence of ERalpha or ERbeta. Moreover, Nar stimulation induces the activation of p38/MAPK leading to the pro-apoptotic caspase-3 activation and to the poly(ADP-ribose) polymerase cleavage in all cancer cell lines considered. Notably, Nar shows an anti-estrogenic effect only in ERalpha containing cells; whereas in ERbeta containing cells, Nar mimics the 17beta-estradiol effects. These findings indicate new steps in the mechanism underlying ER-dependent anti-proliferative effects of Nar suggesting new potential chemopreventive actions of flavonoids on cancer growth.
authors.affiliation: Department of Biology, University Roma Tre, Viale G. Marconi, 446, I-00146 Rome, Italy.
authors.forename: Pierangela
authors.initials: P
authors.lastname: Totta
authors.forename: Filippo
authors.initials: F
authors.lastname: Acconcia
authors.forename: Stefano
authors.initials: S
authors.lastname: Leone
authors.forename: Irene
authors.initials: I
authors.lastname: Cardillo
authors.forename: Maria
authors.initials: M
authors.lastname: Marino
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis; D015153:Blotting, Western; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002460:Cell Line; D045744:Cell Line, Tumor; D002470:Cell Survival; D004958:Estradiol / Q000378:metabolism; D004965:Estrogen Antagonists / Q000494:pharmacology; D047628:Estrogen Receptor alpha / Q000378:metabolism*; D047629:Estrogen Receptor beta / Q000378:metabolism*; D044950:Flavanones / Q000494:pharmacology*; D006367:HeLa Cells; D006801:Humans; D015151:Immunoblotting; D008956:Models, Chemical; D009369:Neoplasms / Q000473:pathology*; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D015398:Signal Transduction; D013997:Time Factors; D014162:Transfection
chemical_list: D000970:Antineoplastic Agents; D000975:Antioxidants; D004965:Estrogen Antagonists; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D044950:Flavanones; D004958:Estradiol; D011065:Poly(ADP-ribose) Polymerases; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases; C005273:naringenin