cDNA Microarray Analysis of Differential Gene Expression in Candida albicans Biofilm Exposed to Farnesol

Abstract

ABSTRACT Candida albicans biofilms are structured microbial communities with high levels of drug resistance. Farnesol, a quorum-sensing molecule that inhibits hyphal formation in C. albicans , has been found to prevent biofilm formation by C. albicans . There is limited information, however, about the molecular mechanism of farnesol against biofilm formation. We used cDNA microarray analysis to identify the changes in the gene expression profile of a C. albicans biofilm inhibited by farnesol. Confocal scanning laser microscopy was used to visualize and confirm normal and farnesol-inhibited biofilms. A total of 274 genes were identified as responsive, with 104 genes up-regulated and 170 genes down-regulated. Independent reverse transcription-PCR analysis was used to confirm the important changes detected by microarray analysis. In addition to hyphal formation-associated genes (e.g., TUP1 , CRK1 , and PDE2 ), a number of other genes with roles related to drug resistance (e.g., FCR1 and PDR16 ), cell wall maintenance (e.g., CHT2 and CHT3 ), and iron transport (e.g., FTR2 ) were responsive, as were several genes encoding heat shock proteins (e.g., HSP70 , HSP90 , HSP104 , CaMSI3 , and SSA2 ). Further study of these differentially regulated genes is warranted to evaluate how they may be involved in C. albicans biofilm formation. Consistent with the down-regulation of the cell surface hydrophobicity-associated gene ( CSH1 ), the water-hydrocarbon two-phase assay showed a decrease in cell surface hydrophobicity in the farnesol-treated group compared to that in the control group. Our data provide new insight into the molecular mechanism of farnesol against C. albicans biofilm formation.