Quantitative real-time PCR analysis

RNA was extracted and retro-transcribed as previously described [12 (link)]. cDNA was used to determine the expression of genes listed in Supplementary Table S1. cDNA was used to determine transcript levels by qRT-PCR in a StepOne RT-PCR machine (Applied Biosystems, Foster City, CA, USA) using SYBR^® Select Master Mix (Life Technologies, Carlsbad, CA, USA). Reactions were performed in triplicate and GAPDH used as endogenous control. Data were analysed using the ΔΔCt method. ΔCt was calculated subtracting the average Ct value of GAPDH to the average Ct value of a specific gene for each sample, then ΔΔCt as the difference between the ΔCt for each sample and the ΔCt of empty vector transfected fibroblasts as control. The reported fold expression, expressed as Relative Quantity, was calculated by 2^−ΔΔCt.