TY - JOUR
T1 - Contrasting activities of estrogen receptor beta isoforms in triple negative breast cancer
AU - Yan, Shunchao
AU - Dey, Parama
AU - Ziegler, Yvonne
AU - Jiao, Xin
AU - Kim, Sung Hoon
AU - Katzenellenbogen, John A
AU - Katzenellenbogen, Benita S
N1 - Funding Information:
This research was supported by grants from the Breast Cancer Research Foundation (BCRF-084 to JAK and BSK and BCRF-083 to BSK) and the NIH/NCI (1R01 CA220284 to BSK and JAK). SY was a Visiting Scholar supported in part by 345 Talent Project from Shengjing Hospital of China Medical University. XJ was a Visiting Scholar supported in part by a fellowship from Shenyang Chest Hospital, Shenyang, China. We thank Dr. Dorraya El-Ashry of the University of Minnesota for kindly providing DT28 cells.
Funding Information:
This research was supported by grants from the Breast Cancer Research Foundation (BCRF-084 to JAK and BSK and BCRF-083 to BSK) and the NIH/NCI (1R01 CA220284 to BSK and JAK). SY was a Visiting Scholar supported in part by 345 Talent Project from Shengjing Hospital of China Medical University. XJ was a Visiting Scholar supported in part by a fellowship from Shenyang Chest Hospital, Shenyang, China. We thank Dr. Dorraya El-Ashry of the University of Minnesota for kindly providing DT28 cells.
PY - 2021/1
Y1 - 2021/1
N2 - PURPOSE: Triple negative breast cancer (TNBC), an aggressive subtype of breast cancer, lacks the three major receptors for predicting outcome or targeting therapy. Hence, our aim was to evaluate the potential of estrogen receptor beta (ERβ) as a possible endocrine therapy target in TNBC.METHODS: The expression and prognostic effect of ERβ isoforms were analyzed using TCGA breast tumor data, and the expression of ERβ isoform mRNA and protein in TNBC cell lines was assayed. Endogenous ERβ2 and ERβ5 were knocked down with siRNA, and ERβ2, ERβ5, and ERβ1 were upregulated using a doxycycline-inducible lentiviral system. Cell proliferation, migration and invasion, and specific gene expressions were evaluated.RESULTS: ERβ2 and ERβ5 were the predominant endogenous forms of ERβ in TNBC tumors and cell lines. High ERβ2 predicted worse clinical outcome. Knockdown of endogenous ERβ2/ERβ5 in cell lines suppressed proliferation, migration and invasion, and downregulated proto-oncogene survivin expression. ERβ2/ERβ5 upregulation did the reverse, increasing survivin and these cell activities. ERβ1 was barely detectable in TNBC cell lines, but its upregulation reduced survivin, increased tumor suppressor expression (E-cadherin and cystatins), and suppressed proliferation, migration and invasion in both ligand-independent and dependent manners, suggesting the possible translational benefit of ERβ ligands.CONCLUSIONS: ERβ2/ERβ5 and ERβ1 exhibit sharply contrasting activities in TNBC cells. Our findings imply that delineating the absolute amounts and relative ratios of the different ERβ isoforms might have prognostic and therapeutic relevance, and could enable better selection of optimal approaches for treatment of this often aggressive form of breast cancer.
AB - PURPOSE: Triple negative breast cancer (TNBC), an aggressive subtype of breast cancer, lacks the three major receptors for predicting outcome or targeting therapy. Hence, our aim was to evaluate the potential of estrogen receptor beta (ERβ) as a possible endocrine therapy target in TNBC.METHODS: The expression and prognostic effect of ERβ isoforms were analyzed using TCGA breast tumor data, and the expression of ERβ isoform mRNA and protein in TNBC cell lines was assayed. Endogenous ERβ2 and ERβ5 were knocked down with siRNA, and ERβ2, ERβ5, and ERβ1 were upregulated using a doxycycline-inducible lentiviral system. Cell proliferation, migration and invasion, and specific gene expressions were evaluated.RESULTS: ERβ2 and ERβ5 were the predominant endogenous forms of ERβ in TNBC tumors and cell lines. High ERβ2 predicted worse clinical outcome. Knockdown of endogenous ERβ2/ERβ5 in cell lines suppressed proliferation, migration and invasion, and downregulated proto-oncogene survivin expression. ERβ2/ERβ5 upregulation did the reverse, increasing survivin and these cell activities. ERβ1 was barely detectable in TNBC cell lines, but its upregulation reduced survivin, increased tumor suppressor expression (E-cadherin and cystatins), and suppressed proliferation, migration and invasion in both ligand-independent and dependent manners, suggesting the possible translational benefit of ERβ ligands.CONCLUSIONS: ERβ2/ERβ5 and ERβ1 exhibit sharply contrasting activities in TNBC cells. Our findings imply that delineating the absolute amounts and relative ratios of the different ERβ isoforms might have prognostic and therapeutic relevance, and could enable better selection of optimal approaches for treatment of this often aggressive form of breast cancer.
KW - Estrogen receptor beta (ERβ)
KW - Invasion
KW - Migration
KW - Proliferation
KW - Triple negative breast cancer (TNBC)
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U2 - 10.1007/s10549-020-05948-0
DO - 10.1007/s10549-020-05948-0
M3 - Article
C2 - 33001337
SN - 0167-6806
VL - 185
SP - 281
EP - 292
JO - Breast Cancer Research and Treatment
JF - Breast Cancer Research and Treatment
IS - 2
ER -