A novel bystander effect in tamoxifen treatment: PPIB derived from ER+ cells attenuates ER- cells via endoplasmic reticulum stress-induced apoptosis.

ABSTRACT: Tamoxifen (TAM) is the frontline therapy for estrogen receptor-positive (ER+) breast cancer in premenopausal women that interrupts ER signaling. As tumors with elevated heterogeneity, amounts of ER-negative (ER-) cells are present in ER+ breast cancer that cannot be directly killed by TAM. Despite complete remissions have been achieved in clinical practice, the mechanism underlying the elimination of ER- cells during TAM treatment remains an open issue. Herein, we deciphered the elimination of ER- cells in TAM treatment from the perspective of the bystander effect. Markable reductions were observed in tumorigenesis of ER- breast cancer cells by applying both supernatants from TAM-treated ER+ cells and a transwell co-culture system, validating the presence of a TAM-induced bystander effect.

SUBMITTER: Yang T 

PROVIDER: S-EPMC10869711 | biostudies-literature | 2024 Feb

REPOSITORIES: biostudies-literature