A molecular carrier to transport and deliver cisplatin into endometrial cancer cells

The leader peptide of a recombinant MnSOD, conjugated to cisplatin, facilitates delivery of cisplatin into endometrial adeno-carcinoma cells (HBT-112) cells. Clonogenic tests on both, normal (MRC-5) and (HBT-112) cancer cells were made in the presence of rMnSOD-Lp, cisplatin alone or cisplatin conjugated to the rMnSOD-Lp (rMnSOD-Lp-CC). The amount of platinum delivered into the cells was measured through atomic spectrophotometric absorbance. The effects of drug treatments on tumor cells were finally evaluated by light (LM) and (TEM) microscopy. By using 0.5 ,M cisplatin alone on tumor cells, its cytotoxic effect resulted minimal, while in the same concentration of rMnSOD-Lp-CC, no tumor cells survived. The atomic absorbance analysis showed that rMnSOD-Lp-CC delivered approximately 5 times more cisplatin into HTB-112 cells than the amount delivered using cisplatin alone. It is worthy to note that rMnSOD-Lp resulted not toxic at all on all tested cells. By observation at LM, the cells treated with rMnSOD-Lp-CC proved signs of nuclear and cytoplasmic fragmentation, i.e. apoptosis induced by the treatment, as confirmed by TEM analysis. We retain that rMnSOD-Lp deserves to be considered as a molecular carrier to deliver cisplatin directly into tumor cells, and transforming its antireplicative activity in a specific and selective antitumor agent.