downregulation of calcineurin gene is associated with glucantime(®) resiatance in leishmania infantum.

background: pentavalent antimonials are the first line drugs for the treatment of leishmaniasis. unresponsiveness of leishmania spp. to antimonial drugs is a serious problem in some endemic areas. investigations on molecular mechanisms involved in drug resistance are essential for monitoring and managing of the disease. cal-cineurin is an essential protein phosphatase for number of signal transduction pathways in eukaryotic cells and it has a mediated role in apoptosis. this study aimed to determine of biomarker(s) in glucantime® resiatance strain of l. infan-tum. methods: we used cdna amplified fragment length polymorphism (cdna-aflp) and real time-rt pcr assays to compare gene expression profiles at the mrna levels in resistant and susceptible l . infantum field isolates. results: the cdna-aflp results showed downlegulation of calcineurin in resis-tant isolate in comparison with susceptible one. significant downregulation of cal-cineurin (0.42 fold) ( p <0.05) was found in resistant isolate compared to susceptible one by real time-rt pcr. conclusion: this is the first report of calcineurin implication in glucantime ® drug resistance of field (natural) isolate of l. infantum . downregulation of calcineurin could protect parasites from antimonial-induced apoptosis.