ABSTRACT
BACKGROUND: Resistance to pentavalent antimonial drugs has become a serious problem in the treatment of cutaneous leishmaniasis in some endemic areas. Investigations on molecular markers involved in drug resistance are essential for monitoring of the disease. Leishmania-activated C kinase gene (LACK1) is involved in multiple central processes such as signal transduction. According to the probable role of the LACK1 gene in antimony resistance, we used real-time reverse transcription-polymerase chain reaction (PCR) to investigate the expression of this gene in clinical L. tropica strains, which were resistant or sensitive to meglumine antimoniate. METHODS: We analyzed the expression level of LACK in 18 sensitive and 14 resistant L. tropica isolates collected from patients with anthroponotic cutaneous leishmaniasis. After cDNA synthesis, gene expression analysis was performed by quantitative real-time PCR using SYBR Green. In addition, the full length of the LACK gene from six reference strains was cloned and sequenced then deposited in the NCBI database to confirm our strains. RESULTS: Real-time reverse transcription-PCR revealed that the average RNA expression level of LACK in isolates from unresponsive and responsive patients were 0.479 and 4.583, respectively, and expression of LACK was significantly downregulated (9.56-fold) in resistant isolates compared to sensitive ones. CONCLUSION: Results of the present study suggest the probable role of the LACK gene in antimony resistance. Moreover, it can be considered as a potential marker for monitoring antimony resistance in clinical isolates. However, further studies are required to exploit the biological functions of it in antimony resistance.
