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

RUBIO M F, WERBAJH S, CAFFERATA EG, QUAGLINO A, COLÓ GP, NOJEK IM, NAHMOD VE, KORDON E.C AND COSTAS MA.

ONCOGENE

Año: 2006

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.Oncogene advance online publication, 12 December 2005; doi:10.1038/sj.onc.1209176.