Journal Article DKFZ-2025-02851

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png
Tamoxifen metabolites acting via BKCa orchestrate the dynamics of K+ and Ca2+ in breast cancer cells.

 ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;

2025
Soc. Bethesda, Md.

The journal of biological chemistry nn, nn () [10.1016/j.jbc.2025.111015]
 GO

Abstract: And calcium (Ca2+)-activated potassium (K+) channel of large conductance (BKCa) is aberrantly expressed in various breast cancer (BC) subtypes including estrogen receptor (ER) positive tumors. Increased proliferation of BC cells in response to tamoxifen (TAM) and its metabolites (TAM+M) has been shown to rely on the cell's BKCa status. However, the mechanism by which TAM+M impact on BKCa activity to promote malignancy is as of yet not clear. By examining murine MMTV-PyMT tumor-derived BC cells and human BC cell lines with a genetically encoded K+ ion indicator and electrophysiological recordings, we identified BKCa-dependent intracellular K+ signals and currents provoked by treatment with clinically relevant TAM+M in an ER-independent manner. In line with this, genetical or pharmacological blockade of BKCa significantly diminished the TAM+M-induced modulation of BKCa K+ currents and consequently also the intracellular drop of intracellular K+ ions in BC cells. Changes in the K+ balance subsequently triggered intra- and extracellular Ca2+ mobilization, which was in turn stimulated by the TAM+M-BKCa axis. Our results highlight that BKCa 'oncochannels' may modulate the response of BC cells to TAM+M. Activation of the TAM+M-BKCa axis causes significant changes in K+ and Ca2+ ion homeostasis, which ultimately contributes to the outcome of endocrine-based BC pharmacotherapy.

Keyword(s): 4-Hydroxytamoxifen ; BK(Ca,) breast cancer ; Endoxifen ; Estrogen receptor ; K(+) channels ; Tamoxifen

Classification:

Note: epub

Contributing Institute(s):
  1. DKTK Koordinierungsstelle Tübingen (TU01)
Research Program(s):
  1. 899 - ohne Topic (POF4-899) (POF4-899)

Appears in the scientific report 2025
Database coverage:
Medline ; BIOSIS Previews ; Biological Abstracts ; Clarivate Analytics Master Journal List ; Current Contents - Life Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF < 5 ; JCR ; PubMed Central ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection
Click to display QR Code for this record

The record appears in these collections:
Document types > Articles > Journal Article
Public records
Publications database

 Record created 2025-12-09, last modified 2025-12-10



Rate this document:

Rate this document:
1
2
3
 
(Not yet reviewed)