TNF-alpha enhances estrogen-induced cell proliferation of estrogen-dependent breast tumor cells through a complex containing nuclear factor-kappa B.

RUBIO, MF; WERBAJH, S; CAFFERATA, EG; QUAGLINO, A; COLÓ, GP; NOJEK, IM; KORDON EC; NAHMOD VE; COSTAS MA

ONCOGENE

Nature publishing group

Año: 2006 vol. 25 p. 1367 - 1377

0950-9232

Breast tumors are usually classified according to their response to estrogens as hormone-dependent or -independent. In this work, we investigated the role of the proinflammatory cytokine TNF-alpha on the estrogen-receptor-positive T47D breast ductal tumor cells. We have found that TNF-alpha exerts a mitogenic effect, inducing cyclin D1 expression and activation of the transcription factor NF-kappaB. Importantly, activation of NF-kappaB was required for estrogen-induced proliferation and cyclin D1 expression. TNF-alpha enhanced the estrogen response by increasing the levels and availability of NF-kappaB. Chromatin immunoprecipitation analysis suggested that the action of estrogens is mediated by a protein complex that contains the activated estrogen receptor, the nuclear receptor coactivator RAC3 and a member of the NF-kappaB family. Finally, our results demonstrate that activation of this transcription factor could be one of the key signals for estrogen-mediated response.