The Zn(S-pr-thiosal)2 complex attenuates murine breast cancer growth by inducing apoptosis and G1/S cell cycle arrest.

Aim: We investigated the antitumor effects of zinc(II) complex with S-propyl thiosalicylic acid [Zn(S-pr-thiosal)2] in 4T1 murine breast cancer model. Results: The Zn(S-pr-thiosal)2 complex reduced primary tumor growth in vivo and induced tumor cell apoptosis. The Zn(S-pr-thiosal)2 complex disrupted the balance between pro- and antiapoptotic Bcl-2 family members in 4T1 cells and induced G1/S cell cycle arrest. The Zn(S-pr-thiosal)2 complex increased the percentage of p16, p21 and p27 positive 4T1 cells. There was a significantly decreased expression of STAT3 and its targets c-Myc and cyclin D3 in 4T1 cells treated with the Zn(S-pr-thiosal)2 complex thus contributing to G1/S cell cycle arrest and/or apoptosis. Conclusion: Our data suggest that the Zn(S-pr-thiosal)2 complex restricted tumor growth through induction of mitochondrial-driven apoptosis and suppression of cell cycle progression.