Total RNA from transfected cells was isolated using the NucleoSpin RNA II kit (Macherey-Nagel). The first strand of cDNA was obtained with SuperScript Reverse Transcriptase (Invitrogen) from 1 mg of RNA, according to the manufacturer's instructions. Primers used in the experiment were designed to amplify 209 bp of the firefly luciferase transcript (forward: 5 0 -TCGTTGACCGCCT GAAGTCT-3 0 , reverse: 5 0 -GGCGACGTAATCCACGA TCT-3 0 ) and, as a reference, 232 bp of the Renilla luciferase transcript (forward: 5 0 -TGGAGCCATTCAA GGAGAAG-3 0 , reverse: 5 0 -TTCACGAACTCGGTGT TAGG-3 0 ). Quantitative PCR was performed using ABI Prism 7000 Sequence Detection System (Applied Biosystems). Power SYBR Green PCR Master Mix (Applied Biosystems) was used for detection. PCR was performed in the following conditions: precycling hold at 958C for 10 min, cycles: 958C, 30 s, 568C, 30 s, 728C, 30 s, up to 40. The ÁÁC T method was used for quantity calculations (23) . The slope of the validation curve was 50.1, which ensures, that target and reference efficiencies are approximately equal.