Anthracyclines effects on polyamine uptake and proliferation of T. cruzi epimastigotes

RUIZ, MD; L. FRACCAROLI,; BALCAZAR, D; MARÍA L. SBARAGLINI; L. LAROCCA; CAROLINA CARRILLO

Congreso; Drug Discovery for Neglected Diseases International; 2018

Chagas diseases an endemic parasitosis originally from Latin America, caused by theprotozoan Trypanosoma cruzi (T. cruzi). The current therapies arelimited in efficacy and show multiple side effects. Thus, there is a need toidentify new effective and specific trypanocidal strategies.Anthracyclines, used asanticancer agents, exert their citotoxicity by blocking DNA metabolism. Inhumans, these are transported into cells by the organic cation transporter hOCT1[1]. Previous results have shown that these compounds inhibit DNA topoisomerasesfrom trypanosomatids [2], however no specific transporters have been identifed. Aim: As hOCT1 functionsas a low affinity polyamine permease, we were interested in analyzing the interactionand/or incorporation of anthracyclines in T.cruzi by the putrescine permease TcPAT12[3], a member of the TcAAAPtransporters family [4]. Methods & Materials: Anthracyclines tested wereDaunorubicin (Dnr) and Doxorubicin (Dxr). We evaluated T. cruzi epimastigotesproliferation and viability by growth curves and MTT assay under differentculture conditions. The strains assayed were Y-GFP (control) and Y-TcPAT12-GFP (overexpressing TcPAT12 permease). To evaluate theeffects of Dnr y Dxr, transport assays were performed for putrescine (TcPAT12), arginine (TcAAAP411) and riboflavin (TcRibj)[5]. Results: Dnr y Dxr significantly decreased T. cruzi epimastigotesproliferation rate in a dose dependent manner, assesed by MTT and cell counting.Growth curves showed that higher anthracyclines concentration is required toaffect the proliferation of Y-TcPAT12-GFPstrain compared to control. Both strains became more sensitive to Dnr and Dxrwhen epimastigotes were putrescine deprived during 15 days.Putrescine uptakewas affected by Dnr and Dxr in both strains under study. Percentage ofputrescine uptake respect to untreated epimastigotes: control + Dnr 50uM:46.4±8.8% vs TcPAT12 + Dnr 50uM:78.2±2.5%; control + Dxr 50uM: 59.9±2.4% vs TcPAT12+ Dxr 50uM: 91.4±8.6%. Arginine andriboflavin uptake was not affected under these conditions. Conclusion: The findings presented herein showed that Dnr andDxr affect T. cruzi epimastigotessurvival and proliferation. This effect could be related to the decrease ofpolyamine uptake and/or to anthracyclines incorporation by TcPAT12 transporter and their intracellular toxic effects.