Avaliação in vitro de potenciais biomarcadores de nefrotoxicidade através de expressão gênica utilizando cisplatina

Abstract

Toxicological tests are required to develop new drugs. However, the lack of predictability of in vivo models has increased the failure rate of drug candidates, increasing time and cost for developing a new medicine. In vitro alternative methods may lead to the development of safer drugs, reduce cost, and can be used in preclinical trials of new molecules. The lack of sensitivity of current markers for nephrotoxicity makes its effects are discovered later. Therefore, it is crucial to search for better early biomarkers. Renal system receives large blood flow due to its functions, and therefore it is important target to many drugs. Whereas the molecular and cellular damage precede the histopathological changes, the study of gene expression induced by drugs has becoming important. Once the expression of a set of genes is consistently changed after the exposure to xenobiotics, these genes can be used as biomarkers. Hence, nephrotoxic drugs have been used such as biomarker studies to identify these genes. Cisplatin is a chemotherapeutic agent widely used in medical practice that has in nephrotoxicity its biggest limitation. The major cells affected by cisplatin-induced nephrotoxicity are the proximal tubule. In this study, LLC-PK1 cells were exposed to cisplatin for 48 hours and the concentrations at 1 µM, 6 µM and 15 µM were selected after the MTT assay. The expression of nephrotoxicity related genes was analyzed by real-time PCR in cells exposed to the aforementioned concentrations. Decrease in cell viability observed at concentrations of 1 µM and 6 µM and was not accompanied by changes in gene expression studies and require further research for understanding such as cisplatin affect cell growth. The HAVCR1 (KIM-1), BAX, CASP9, CASP3 and ICAM-1 genes have increased expression after exposure to 15 µM of cisplatin when compared to unexposed cells. The present studys results suggest that these genes may be used as biomarkers in vitro nephrotoxicity, requiring further studies for validation.