Quantitative Analysis of Growth Factor Expression

Total RNA was isolated from the hDPC with RNeasy Mini Kit reagents (Qiagen, Valencia, CA, USA) according to the manufacturer’s instructions. cDNA was synthesized according to the manufacturer’s protocol using maxim RT Pre Mix reagents (iNtRON Biotechnology, Kyungki-Do, Korea) and the following respective forward and reverse primers: 5′-CAGCAGTCTTCCAACCCAAT-3′ and 5′-CCTGCACTCCCTCTACTTGC-3′) for IGF-1, 5′-GCCTGAAAGATATCCCGACA-3′ and 5′-TTCCATGTTCTTGTCCCACA-3′ for HGF, 5′-GACATGGATCCTGCCAACTT-3′ and 5′-GGAAGAAAGTGGGCTGTTTTT-3′ for KGF, 5′-CTACCTCCACCATGCCAAGT-3′ and 5′-GCGAGTCTGTGTTTTTGCAG-3′ for VEGF, and 5′-CGCCAACCGCGAGAAGAT-3′ and 5′-CGCCAACCGCGAGAAGAT-3′ for human β-actin, which served as the internal standard. qRT-PCR analysis was performed using FastStart Essential DNA Green Master Mix (Roche, Indianapolis, IN, USA) in a C1000 Touch Thermal Cycler instrument (Bio-Rad, Hercules, CA, USA). Quantification of marker genes was performed according to the ΔΔCt method^{19 (link)}.