Expression of DDR2 in tumor tissues of PTC with local metastasis and human PTC cell lines. (A) The DDR2 mRNA expression level in tumor tissues and adjacent non-tumor tissues from 10 patients with PTC with local metastasis was detected using RT-qPCR (n=10; P=0.0011). (B) The DDR2 protein expression in tumor tissues and adjacent non-tumor tissues from 10 patients with PTC with local metastasis was detected using western blotting. (C) The DDR2 mRNA expression in human normal follicular cell line (Nthy-ori 3-1) and PTC cell lines (BAPCP, TPC-1 and GLAG-66) was detected by RT-qPCR (*P<0.05 vs. Nthy-ori 3-1). (D) The DDR2 protein expression in Nthy-ori 3-1, BAPCP, TPC-1 and GLAG-66 cell lines was detected by western blotting. RT-qPCR, reverse transcription-quantitative polymerase chain reaction; DDR2, discoidin domain receptor tyrosine kinase 2; PTC, papillary thyroid carcinoma; NT, non-tumor tissue; TT, tumor tissue.