The stepwise selection for ketoconazole resistance induces upregulation of C14-demethylase (CYP51) in Leishmania amazonensis

AUTOR(ES)

Andrade-Neto, Valter Viana, Matos-Guedes, Herbert Leonel de, Gomes, Daniel Cláudio de Oliveira, Canto-Cavalheiro, Marilene Marcuzzo do, Rossi-Bergmann, Bartira, Torres-Santos, Eduardo Caio

FONTE

Memórias do Instituto Oswaldo Cruz

DATA DE PUBLICAÇÃO

2012-05

RESUMO

Ketoconazole is a clinically safe antifungal agent that also inhibits the growth of Leishmania spp. A study was undertaken to determine whether Leishmania parasites are prone to becoming resistant to ketoconazole by upregulating C14-demethylase after stepwise pharmacological pressure. Leishmania amazonensis promastigotes [inhibitory concentration (IC)50 = 2 µM] were subjected to stepwise selection with ketoconazole and two resistant lines were obtained, La8 (IC50 = 8 µM) and La10 (IC50 = 10 µM). As a result, we found that the resistance level was directly proportional to the C14-demethylase mRNA expression level; we also observed that expression levels were six and 12 times higher in La8 and La10, respectively. This is the first demonstration that L. amazonensis can up-regulate C14-demethylase in response to drug pressure and this report contributes to the understanding of the mechanisms of parasite resistance.

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