Moreover, over-expression of miR-145 increased the cleaved-PARP expression and induced apoptosis in breast cancer cells, by repression of oestrogen receptor-α (ER-α) and up-regulation of the TP53 transcriptional targets, such as p53 up-regulated modulator of apoptosis (PUMA) and P21, indicating that miR-145 activates the TP53 pathway and suppresses ER-α 70. Here, TP53 is linked to breast cancer.