Abstract: Objective To explore the role of CTHRC1 in regulating the proliferation and apoptosis of papillary thyroid cancer cells. Methods Papillary thyroid cancer TPC-1 cells were transfected with a small interfering RNA (siRNA) targeting CTHRC1, with the cells transfected with a scrambled sequence as the negative control. The changes in cell proliferation and apoptosis were assessed using cell counting kit-8 (CCK-8) and flow cytometry with AV/PI double staining, respectively. The expression of c-caspase-3, c-PARP1 and phosphorylation of ERK1/2 in the cells were examined with Western blotting. Results Transfection with the siRNA sequence significantly decreased the mRNA and protein levels of CTHRC1 in TCP-1 cells (P<0.05). Compared with blank and negative control cells, TCP-1 cells with RNA interference of CTHRC1 showed significantly lowered proliferative activity and enhanced cell apoptosis (P<0.05) with significantly increased expressions of c-caspase-3 and c-PARP1 and phosphorylation of ERK1/2 (P<0.05). Conclusion RNA interference of CTHRC1 promotes the proliferation and inhibits apoptosis of papillary thyroid cancer cells possibly by activating the ERK1/2 pathway

Key words: thyroid carcinoma; CTHRC1; proliferation; apoptosis; siRNA interference