Notch-1 Activates Estrogen Receptor-alpha-dependent Transcription Via IKKalpha in Breast Cancer Cells
Overview
Affiliations
Approximately 80% of breast cancers express the estrogen receptor-alpha (ERalpha) and are treated with anti-estrogens. Resistance to these agents is a major cause of mortality. We have shown that estrogen inhibits Notch, whereas anti-estrogens or estrogen withdrawal activate Notch signaling. Combined inhibition of Notch and estrogen signaling has synergistic effects in ERalpha-positive breast cancer models. However, the mechanisms whereby Notch-1 promotes the growth of ERalpha-positive breast cancer cells are unknown. Here, we demonstrate that Notch-1 increases the transcription of ERalpha-responsive genes in the presence or absence of estrogen via a novel chromatin crosstalk mechanism. Our data support a model in which Notch-1 can activate the transcription of ERalpha-target genes via IKKalpha-dependent cooperative chromatin recruitment of Notch-CSL-MAML1 transcriptional complexes (NTC) and ERalpha, which promotes the recruitment of p300. CSL binding elements frequently occur in close proximity to estrogen-responsive elements (EREs) in the human and mouse genomes. Our observations suggest that a hitherto unknown Notch-1/ERalpha chromatin crosstalk mediates Notch signaling effects in ERalpha-positive breast cancer cells and contributes to regulate the transcriptional functions of ERalpha itself.
Mechanisms of endocrine resistance in hormone receptor-positive breast cancer.
Gao Y, Yu Y, Zhang M, Yu W, Kang L Front Oncol. 2024; 14:1448687.
PMID: 39544302 PMC: 11560879. DOI: 10.3389/fonc.2024.1448687.
17β-estradiol inhibits Notch1 activation in murine macrophage cell line RAW 264.7.
Severi P, Ascierto A, Marracino L, Ouambo Talla A, Aquila G, Martino V Mol Biol Rep. 2024; 51(1):1134.
PMID: 39514048 DOI: 10.1007/s11033-024-10058-x.
Riley C, Ammar U, Alsfouk A, Anthony N, Baiget J, Berretta G Molecules. 2024; 29(15).
PMID: 39124921 PMC: 11314561. DOI: 10.3390/molecules29153515.
Vigolo M, Urech C, Lamy S, Monticone G, Zabaleta J, Hossain F Cancers (Basel). 2023; 15(15).
PMID: 37568775 PMC: 10416998. DOI: 10.3390/cancers15153957.
Alam S, Wang L, Zhu Z, Hoeppner L NPJ Precis Oncol. 2023; 7(1):33.
PMID: 36966223 PMC: 10039943. DOI: 10.1038/s41698-023-00370-3.