NFkB signaling is important for growth of antiestrogen resistant breast cancer cells
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NFkB signaling is important for growth of antiestrogen resistant breast cancer cells. / Yde, Christina Westmose; Emdal, Kristina Bennet; Guerra, Barbara; Lykkesfeldt, Anne E.
In: Breast Cancer Research and Treatment, Vol. 135, No. 1, 2012, p. 67-78.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - NFkB signaling is important for growth of antiestrogen resistant breast cancer cells
AU - Yde, Christina Westmose
AU - Emdal, Kristina Bennet
AU - Guerra, Barbara
AU - Lykkesfeldt, Anne E
PY - 2012
Y1 - 2012
N2 - Resistance to endocrine therapy is a major clinical challenge in current treatment of estrogen receptor-positive breast cancer. The molecular mechanisms underlying resistance are yet not fully clarified. In this study, we investigated whether NF¿B signaling is causally involved in antiestrogen resistant cell growth and a potential target for re-sensitizing resistant cells to endocrine therapy. We used an MCF-7-derived cell model for antiestrogen resistant breast cancer to investigate dependence on NF¿B signaling for antiestrogen resistant cell growth. We found that targeting NF¿B preferentially inhibited resistant cell growth. Antiestrogen resistant cells expressed increased p50 and RelB, and displayed increased phosphorylation of p65 at Ser529 and Ser536. Moreover, transcriptional activity of NF¿B after stimulation with tumor necrosis factor a was enhanced in antiestrogen resistant cell lines compared to the parental cell line. Inhibition of NF¿B signaling sensitized tamoxifen resistant cells to the growth inhibitory effects of tamoxifen but was not sufficient to fully restore sensitivity of fulvestrant resistant cells to fulvestrant. In support of this, depletion of p65 with siRNA in tamoxifen resistant cells increased sensitivity to tamoxifen treatment. Our data provide evidence that NF¿B signaling is enhanced in antiestrogen resistant breast cancer cells and plays an important role for antiestrogen resistant cell growth and for sensitivity to tamoxifen treatment in resistant cells. Our results imply that targeting NF¿B might serve as a potential novel treatment strategy for breast cancer patients with resistance toward antiestrogen.
AB - Resistance to endocrine therapy is a major clinical challenge in current treatment of estrogen receptor-positive breast cancer. The molecular mechanisms underlying resistance are yet not fully clarified. In this study, we investigated whether NF¿B signaling is causally involved in antiestrogen resistant cell growth and a potential target for re-sensitizing resistant cells to endocrine therapy. We used an MCF-7-derived cell model for antiestrogen resistant breast cancer to investigate dependence on NF¿B signaling for antiestrogen resistant cell growth. We found that targeting NF¿B preferentially inhibited resistant cell growth. Antiestrogen resistant cells expressed increased p50 and RelB, and displayed increased phosphorylation of p65 at Ser529 and Ser536. Moreover, transcriptional activity of NF¿B after stimulation with tumor necrosis factor a was enhanced in antiestrogen resistant cell lines compared to the parental cell line. Inhibition of NF¿B signaling sensitized tamoxifen resistant cells to the growth inhibitory effects of tamoxifen but was not sufficient to fully restore sensitivity of fulvestrant resistant cells to fulvestrant. In support of this, depletion of p65 with siRNA in tamoxifen resistant cells increased sensitivity to tamoxifen treatment. Our data provide evidence that NF¿B signaling is enhanced in antiestrogen resistant breast cancer cells and plays an important role for antiestrogen resistant cell growth and for sensitivity to tamoxifen treatment in resistant cells. Our results imply that targeting NF¿B might serve as a potential novel treatment strategy for breast cancer patients with resistance toward antiestrogen.
U2 - 10.1007/s10549-012-2053-1
DO - 10.1007/s10549-012-2053-1
M3 - Journal article
C2 - 22527100
VL - 135
SP - 67
EP - 78
JO - Breast Cancer Research and Treatment
JF - Breast Cancer Research and Treatment
SN - 0167-6806
IS - 1
ER -
ID: 41844514