Sex hormone-binding globulin, the plasma carrier for sex steroids, inhibits the estradiol-induced proliferation of breast cancer cells. Estradiol induces cell proliferation triggering multiple mechanisms. Besides regulating growth factors, it activates Erk-1/-2, thus inhibiting apoptosis. In the present study, we investigated the effect of SHBG on estradiol-mediated anti-apoptotic effect in MCF-7 breast cancer cells. As expected, estradiol reduced the number of cells undergoing apoptosis. Although no modification of estradiol action was observed in cells treated contemporarily with estradiol and SHBG, pre-incubation with SHBG before estradiol treatment contrasted the anti-apoptotic effect completely. A mutant form of SHBG, lacking the O-linked oligosaccharide in Thr(7), displayed no such effect. Moreover, SHBG prevented the estradiol-induced phosphorylation of Erk-1/-2, whereas it had no effect on estradiol-induced transcription. Taken together, our observations suggest that the interaction of SHBG with MCF-7 cell membranes causes inhibition of the anti-apoptotic effect of estradiol which might account for SHBG's inhibitory effect on breast cancer cell growth.

Sex hormone-binding globulin antagonizes the anti-apoptotic effect of estradiol in breast cancer cells

CATALANO, Maria Graziella;FRAIRIA, Roberto;BOCCUZZI, Giuseppe;
2005

Abstract

Sex hormone-binding globulin, the plasma carrier for sex steroids, inhibits the estradiol-induced proliferation of breast cancer cells. Estradiol induces cell proliferation triggering multiple mechanisms. Besides regulating growth factors, it activates Erk-1/-2, thus inhibiting apoptosis. In the present study, we investigated the effect of SHBG on estradiol-mediated anti-apoptotic effect in MCF-7 breast cancer cells. As expected, estradiol reduced the number of cells undergoing apoptosis. Although no modification of estradiol action was observed in cells treated contemporarily with estradiol and SHBG, pre-incubation with SHBG before estradiol treatment contrasted the anti-apoptotic effect completely. A mutant form of SHBG, lacking the O-linked oligosaccharide in Thr(7), displayed no such effect. Moreover, SHBG prevented the estradiol-induced phosphorylation of Erk-1/-2, whereas it had no effect on estradiol-induced transcription. Taken together, our observations suggest that the interaction of SHBG with MCF-7 cell membranes causes inhibition of the anti-apoptotic effect of estradiol which might account for SHBG's inhibitory effect on breast cancer cell growth.
230
31
37
M.G. CATALANO; R. FRAIRIA; G. BOCCUZZI; N. FORTUNATI
File in questo prodotto:
File Dimensione Formato  
Mol Cell Endo Catalano Frairia.pdf

Accesso riservato

Tipo di file: PDF EDITORIALE
Dimensione 252.47 kB
Formato Adobe PDF
252.47 kB Adobe PDF   Visualizza/Apri   Richiedi una copia
307653_MCE 2010_4aperto.pdf

Accesso aperto

Tipo di file: POSTPRINT (VERSIONE FINALE DELL’AUTORE)
Dimensione 624.69 kB
Formato Adobe PDF
624.69 kB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2318/37578
Citazioni
  • ???jsp.display-item.citation.pmc??? 14
  • Scopus 47
  • ???jsp.display-item.citation.isi??? 42
social impact