In this study, our results indicate that down-regulation of DBCCR1-003 in BC is responsible for the down-regulation of DBCCR1 via DNMT1, and overexpression of DBCCR1-003 can inhibit cell growth by inducing apoptosis and arresting the cell cycle in phase in T24 cells, revealing a new lncRNA DBCCR1-003 which can affect the tumorigenesis and development of BC by mediating tumor suppress gene DBCCR1 via DNMT1. This evidence concerns the gene DNMT1 and breast cancer.