Adv Pharm Bull. 2017;7(1):53-59.
doi: 10.15171/apb.2017.007
PMID: 28507937
PMCID: PMC5426734
Scopus id: 85017558190
  Abstract View: 331
  PDF Download: 276

Research Article

The Utilization of RNA Silencing Technology to Mitigate the Voriconazole Resistance of Aspergillus Flavus; Lipofectamine-Based Delivery

Sanam Nami 1, Behzad Baradaran 2, Behzad Mansoori 2, Parivash Kordbacheh 1, Sasan Rezaie 1, Mehraban Falahati 3, Leila Mohamed Khosroshahi 4, Mahin Safara 1, Farideh Zaini 1 *

1 Department of Medical Mycology and Parasitology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
2 Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
3 Department of Medical Mycology and Parasitology, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran.
4 Department of Immunology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.


Purpose: Introducing the effect of RNAi in fungi to downregulate essential genes has made it a powerful tool to investigate gene function, with potential strategies for novel disease treatments. Thus, this study is an endeavor to delve into the silencing potentials of siRNA on cyp51A and MDR1 in voriconazole-resistant Aspergillus flavus as the target genes.

Methods: In this study, we designed three cyp51A-specific siRNAs and three MDR1-specific siRNAs and after the co-transfection of siRNA into Aspergillus flavus, using lipofectamine, we investigated the effect of different siRNA concentrations (5, 15, 25, 50nM) on cyp51A and MDR1 expressions by qRT-PCR. Finally, the Minimum Inhibitory Concentrations (MICs) of voriconazole for isolates were determined by broth dilution method.

Results: Cyp51A siRNA induced 9, 22, 33, 40-fold reductions in cyp51A mRNA expres­sion in a voriconazole-resistant strain following the treatment of the cells with concentrations of 5, 15, 25, 50nM siRNA, respectively. Identically, the same procedure was applied to MDR1, even though it induced 2, 3, 4, 10-fold reductions. The results demonstrated a MIC for voriconazole in the untreated group (4µg per ml), when compared to the group treated with cyp51A-specific siRNA and MDR1-specific siRNA, both at concentrations of 25 and 50nM, yielding 2µg per ml and 1µg per ml when 25 nM was applied and 2µg per ml and 0.5µg per ml when the concentration doubled to 50 nM.

Conclusion: In this study, we suggested that siRNA-mediated specific inhibition of cyp51A and MDR1 genes play roles in voriconazole-resistant A.flavus strain and these could be apt target genes for inactivation. The current study promises a bright prospect for the treatment of invasive aspergillosis through the effective deployment of RNAi and gene therapy.

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