Histone H3 lysine 23 acetylation is associated with oncogene TRIM24 expression and a poor prognosis in breast cancer.

Acetylated H3 lysine 23 (H3K23ac) is a specific histone post-translational modification recognized by oncoprotein TRIM24. However, it is not clear whether H3K23ac levels are correlated with TRIM24 expression and what role H3K23ac may have in cancer. In this study, we collected breast carcinoma samples from 121 patients and conducted immunohistochemistry to determine the levels of TRIM24 and H3K23ac in breast cancer. Our results demonstrated that TRIM24 expression is positively correlated with H3K23ac levels, and high levels of both TRIM24 and H3K23ac predict shorter overall survival of breast cancer patients. We also showed that both TRIM24 and H3K23ac are higher in HER2-positive patients, and their levels were positively correlated with HER2 levels in breast cancer. Moreover, TRIM24 expression is associated with estrogen receptor (ER) and progesterone receptor (PR) statuses in both our cohort and The Cancer Genome Atlas (TCGA) breast carcinoma. In summary, our results revealed an important role of TRIM24 and H3K23ac in breast cancer and provided further evidence that TRIM24 small-molecule inhibitors may benefit ER- and PR-negative or HER2-positive breast cancer patients.