Antitumor Activity of Palladium(II) Complexes on DU-145 Cell Line in Vitro

In the area of non-platinum complexes, various complexes containing gold, copper, ruthenium, and palladium have shown a strong cytotoxic effect on different cancer cell lines. The aim of our study was to examine the cytotoxicity of the Pd(II) complexes (C1-C5) and the corresponding ligands (L1-L5) on the DU-145 prostate cancer cell line. Also, due to its clinical application, the cytotoxicity of cisplatin has been examined. Our findings showed that C1- C5 complexes and cisplatin show dose-dependent and strong cytotoxic effects against the DU-145 cell line in vitro. Furthermore, the results demonstrated that early apoptosis was induced by all five Pd(II) complexes. Also, the results showed that complexes C1, C3, and C5 induced G0/G1 phase arrest on DU- 145 cells. Pd(II) complex C2 induced S phase arrest, while C4 complex induced G2/M phase arrest on cancer cells. Additionally, all tested complexes significantly reduced the amount of antiapoptotic protein Bcl-2. Also, there was a significant increase in the concentration of proapoptotic Bax protein in DU-145 cells treated C1-C5 complexes. The results of our research demonstrated that Pd(II) complexes induced apoptosis via the mitochondrial pathway. Thus, it is crucial to further investigate the cytotoxicity of these Pd(II) complexes in vivo. Complex C2 might be a good candidate for a new generation of anticancer drugs.