The induction of cell death by phosphine silver(I) thiocyanate complexes in SNO-esophageal cancer cells.

Esophageal cancer is one of the least studied cancers and is found to be prominent in black South African males. It is mainly diagnosed in the late stages, and patients tend to have a low 5-year survival rate of only 10%. Silver is generally used as an antimicrobial agent, with limited reports on anticancer studies. In this study, dimeric silver(I) thiocyanate complexes were used containing a variation of 4-substitued triphenylphosphines, including [AgSCN(PPh(3))(2)](2) (1), [AgSCN{P(4-MeC(6)H(4))(3)}(2)](2) (2), [AgSCN{P(4-FC(6)H(4))(3)}(2)](2) (3) and [AgSCN{P(4-ClC(6)H(4))(3)}(2)](2) (4). All four complexes, with their respective phosphine ligands, PPh(3) (L1), P(4-MeC(6)H(4))(3) (L2), P(4-FC(6)H(4))(3) (L3) and P(4-ClC(6)H(4))(3) (L4), were subjected to in vitro toxicity studies in SNO-esophageal cancer cells, using an alamarBlue(®) assay. Morphological changes, including blebbing and apoptotic body formation, were observed. Phosphatidylserine externalization, a marker of apoptosis, was quantified by flow cytometry. The phosphine ligands L1-L4, on their own, had minimal effect on the malignant while complexes 1-4 resulted in significant cell death. A 10x decreased concentration of these complexes had similar effects than cisplatin, used as the positive control. These complexes show promise as anticancer agents.