Quantitative real-time polymerase chain reaction (qRT-PCR) was
performed using a Platinum® SYBR® Green qPCR SuperMix-UDG kit
(Invitrogen) according to the manufacturer's instructions. Each reaction
contained the cDNA reverse-transcribed from 50 ng of RNA and 125 nM
(each) of one of the pairs of primers in Table 1. Amplicon size was determined
by agarose gel electrophoresis and the identity of each amplicon
was confirmed by nucleotide sequencing. Primer efficiency was determined
using at least five different dilutions (spanning at least five
orders of magnitude) of the purified PCR products for each of the
genes as the template for qRT-PCR. Primer efficiency values close to
1.0 are considered acceptable (Kubista et al., 2006). The qRT-PCR reactions
were performed and the resulting data were analysed using a
Rotorgene 3000 thermal cycler (Corbett Research). The fluorescence
curves produced for each sample were used to calculate the threshold
cycle (Ct) values. Using these values, the fold-change in expression
normalised to β-actin and relative to the control cells was calculated
using the 2−ΔΔCt method (Livak and Schmittgen, 2001).