YEATS4 is associated with poor prognosis and promotes epithelial-to-mesenchymal transition and metastasis by regulating ZEB1 expression in breast cancer.

YEATS domain-containing protein 4 (YEATS4) is implicated in several oncogenic signaling pathways, and its expression is involved in various types of cancer; regardless, the pathophysiologic effects of YEATS4 on breast cancer remain unclear. This study finds that YEATS4 is increasingly expressed with breast cancer progression, and its expression is related to poor outcome and distant metastasis. YEATS4 overexpression in breast cancer cells strengthens their malignant characteristics and , particularly inducing epithelial-to-mesenchymal transition (EMT) and consequently, metastatic capability in breast cancer cells. By contrast, deleting YEATS4 in breast cancer cells with high-grade malignancy reduced these characteristics. With regard to the molecular mechanism, YEATS4 mediates histone H3K27ac at specific sites of the ZEB1 promoter to regulate its expression at the transcription level. Depleting ZEB1 blocks YEATS4-induced EMT, migration, invasion, and metastasis. YEATS4 expression is also positively correlated with ZEB1 expression in patients with breast cancer. Co-expression of YEATS4 and ZEB1 correlates with the shortest distant metastasis-free period. Taken together, our data reveal the critical role of YEATS4 in the progression and metastasis of breast cancer, as well as support YEATS4 as a potential therapeutic target and prognostic biomarker for breast cancer.