SP3 and cancer: It has also been reported that zinc depletion induces apoptosis and decreases Sp1, Sp3 and Sp4 in cancer cell lines [32], [33], and we confirmed that aspirin-induced PARP cleavage and downregulation of Sp1, Sp3 and Sp4 was inhibited in RKO and SW480 cells cotreated with aspirin plus ZnSO4 (Figs. 7D and 7E).