High expression of SETDB1 mediated by miR-29a-3p associates with poor prognosis and immune invasion in breast invasive carcinoma

BACKGROUND: Breast invasive carcinoma (BRCA) has a poor prognosis. Numerous studies have shown that SET domain bifurcated histone lysine methyltransferase 1 (SETDB1) is involved in the initiation and progression of many cancers. This study aims to reveal the potential mechanism of SETDB1 in the development and progression of BRCA. METHODS: The ONCOMINE database, TIMER database, UALCAN database and GEPIA database were used to analyze the expression of SETDB1 in human cancers. We evaluated the expression level of SETDB1 in cell lines by quantitative real-time polymerase chain reaction (qPCR), and the survival analysis of SETDB1 was performed on PrognoScan and Kaplan-Meier plotter websites. The upstream regulator was obtained from starBase database. RESULTS: We confirmed that SETDB1 messenger RNA (mRNA) level showed high expression in breast cell lines, and we also found that SETDB1 showed high expression in many types of cancers. Moreover, SETDB1 overexpression was positively correlated with poor prognosis in BRCA. Furthermore, we first predicted miR-29a-3p was a potential upstream regulator of SETDB1 in BRCA. Our findings indicated that SETDB1 might play a carcinogenic role by increasing the infiltration of immune cell and influencing immune checkpoint expression. CONCLUSIONS: This study suggested that miR-29a-3p can mediate the expression of SETDB1 with poor prognosis and tumor immune infiltration in BRCA.