Pt(IV)Ac-POA: new platinum compound Induced caspase independent apoptosis In B50 neuroblastoma stem cells

Neuroblastoma is a tumour that affects adults and children, characterized by a stem cells component. To date, cisplatin is the main antitumor agent used in the clinical treatment of this tumour; however, it induces side effects such as neurotoxicity in healthy cells and induces chemo resistance to therapy in cancer cells. New platinum-based compounds, platinum (II) have recently been synthesized, and due to their chemical characteristics, they are able to identify new cellular targets. These complexes act as prodrugs and performing their cytotoxic effect as platinum (II) after a reduction reaction within the hypoxic tumour cells. Among these prodrugs, Pt(IV)Ac-POA appears to be very promising, thanks to the presence of ligand (2 propinyl)octanoic acid (POA), which acts as an inhibitor of histone deacetylase (HDACi) and leads to the increase of histone acetylation, decreasing the interactions between histone and DNA, so as to produce chemo-sensitization to DNA-damaging agents. The greater cytotoxic effect of Pt(IV)Ac-POA on tumour cells, would therefore be mainly due to the mechanism of inhibition of histone deacetylase, which would increase the accessibility of DNA to platination mechanisms that induce cell death. In this study the results show that Pt(IV)Ac-POA, used at a concentration ten times lower than cisplatin, can induce apoptosis in B50 cells in culture both through the intrinsic pathway and through the independent caspase pathway. The data, obtained by immunohistochemical techniques in fluorescence microscopy, show that treatment with Pt(IV)Ac-POA has a greater proapoptotic effect on stem cells compared to the cisplatin standard treatment.