Total RNA was extracted with TRIzol Reagent (Invitrogen, Carlsbad, CA, USA) and cDNA was synthesized from 1 μg of total RNA using a TransScript All-in-One First-Strand cDNA Synthesis SuperMix (Transgen Biotech, Beijing, China). Next, qRT-PCR was performed progressively using FastStart Universal SYBR Green Master Mix (Roche, Indianapolis, IN, USA) in an ABI PRISM® 7900HT System (Applied Biosystems, Foster City, CA, USA). Beta-actin was used for normalization of the results. Primers used in the present study are as described previously 30 (link).