To synthesize cDNA from cells, RNA was isolated using Qiagen RNeasy mini kit according to manufacturer's instruction. In brief, cells were lysed in the presence of b-mercaptoethanol and lysates were loaded to a column, washed and eluted in RNase-free water. For reverse transcription 3 mg total RNA, 0.5 mg oligo dT primer in a total volume of 12 ml were heated for 10 minutes at 70uC. Enzyme mix was prepared (56 Enzyme Buffer (Fermentas), water and 500 mM dNTPs) and pre-warmed at 42uC for 2 minutes before adding 535 U/100 ml RevertAid H 2 M-MuLV (Fermentas).