MiRNA-378 Is Downregulated by XBP1 and Inhibits Growth and Migration of Luminal Breast Cancer Cells
Overview
Chemistry
Molecular Biology
Authors
Affiliations
X-box binding protein 1 (XBP1) is a transcription factor that plays a crucial role in the unfolded protein response (UPR), a cellular stress response pathway involved in maintaining protein homeostasis in the endoplasmic reticulum (EnR). While the role of XBP1 in UPR is well-characterised, emerging evidence suggests its involvement in endocrine resistance in breast cancer. The transcriptional activity of spliced XBP1 (XBP1s) is a major component of its biological effects, but the targets of XBP1s in estrogen receptor (ER)-positive breast cancer are not well understood. Here, we show that the expression of miR-378 and PPARGC1B (host gene of miR-378) is downregulated during UPR. Using chemical and genetic methods, we show that XBP1s is necessary and sufficient for the downregulation of miR-378 and PPARGC1B. Our results show that overexpression of miR-378 significantly suppressed cell growth, colony formation, and migration of ER-positive breast cancer cells. Further, we found that expression of miR-378 sensitised the cells to UPR-induced cell death and anti-estrogens. The expression of miR-378 and PPARGC1B was downregulated in breast cancer, and higher expression of miR-378 is associated with better outcomes in ER-positive breast cancer. We found that miR-378 upregulates the expression of several genes that regulate type I interferon signalling. Analysis of separate cohorts of breast cancer patients showed that a gene signature derived from miR-378 upregulated genes showed a strong association with improved overall and recurrence-free survival in breast cancer. Our results suggest a growth-suppressive role for miR-378 in ER-positive breast cancer where downregulation of miR-378 by XBP1 contributes to endocrine resistance in ER-positive breast cancer.
Potential therapies for non-coding RNAs in breast cancer.
Li R, Ji Y, Ye R, Tang G, Wang W, Chen C Front Oncol. 2024; 14:1452666.
PMID: 39372872 PMC: 11449682. DOI: 10.3389/fonc.2024.1452666.
Liu Y, Dong L, Ma J, Chen L, Fang L, Wang Z Clin Exp Med. 2024; 24(1):113.
PMID: 38795164 PMC: 11127859. DOI: 10.1007/s10238-024-01372-6.
Karamali N, Daraei A, Rostamlou A, Mahdavi R, Jonoush Z, Ghadiri N Cancer Cell Int. 2024; 24(1):104.
PMID: 38468244 PMC: 10926595. DOI: 10.1186/s12935-024-03296-3.