Gene amplification and point mutations in pyrimidine metabolic genes in 5-fluorouracil resistant Leishmania infantum.

• Published in: PLoS Neglected Tropical Diseases
• Main Authors: Jean-François Ritt, Frédéric Raymond, Philippe Leprohon, Danielle Légaré, Jacques Corbeil, Marc Ouellette
• Format: Article in Journal/Newspaper
• Language: English
• Published: Public Library of Science (PLoS) 2013
• Subjects: Arctic medicine. Tropical medicine; RC955-962; Public aspects of medicine; RA1-1270; Arctic
• Online Access: https://doi.org/10.1371/journal.pntd.0002564; https://doaj.org/article/dc5d49615973427fb11c5d47d452b3be

The human protozoan parasites Leishmania are prototrophic for pyrimidines with the ability of both de novo biosynthesis and uptake of pyrimidines.Five independent L. infantum mutants were selected for resistance to the pyrimidine analogue 5-fluorouracil (5-FU) in the hope to better understand the metabolism of pyrimidine in Leishmania. Analysis of the 5-FU mutants by comparative genomic hybridization and whole genome sequencing revealed in selected mutants the amplification of DHFR-TS and a deletion of part of chromosome 10. Point mutations in uracil phosphorybosyl transferase (UPRT), thymidine kinase (TK) and uridine phosphorylase (UP) were also observed in three individual resistant mutants. Transfection experiments confirmed that these point mutations were responsible for 5-FU resistance. Transport studies revealed that one resistant mutant was defective for uracil and 5-FU import.This study provided further insights in pyrimidine metabolism in Leishmania and confirmed that multiple mutations can co-exist and lead to resistance in Leishmania.