Lentivirus-mediated shRNA interference of trefoil factor 3 blocks cell viability, migration and invasion in the papillary thyroid carcinoma cells.

Trefoil factor 3 (TFF3), a regulatory protein composed of 59 amino acids, has been suggested to be involved in pathogen- esis, proliferation, invasion, migration and apoptosis in multiple malignant tumors. However, the roles of TFF3 concerning the viability, migration and invasion in papillary thyroid carcinoma cells have not yet been studied. This study aimed to investigate the effect of TFF3 knockdown on a thyroid papillary carcinoma TPC-1 cell line both in vitro and in vivo. In the present study, lentivirus-mediated short hairpin RNA (shRNA) targeting TFF3 plasmids were first constructed and stable TPC-1 cells were obtained while their TFF3 gene was silenced with either shTFF3-TPC-1, or a scrambled shRNA control. TFF3 expression was detected using quantitative real-time PCR and western blot analyses. The TPC-1 cell viability was measured by CCK-8 assay and colony formation. The cell migration and invasion were assessed by wound scratch assay and transwell filters. AKT phosphorylation, MMP-9, and BCL-2 expression levels were detected by western blot analyses. Our results showed that TFF3 knockdown significantly inhibits TPC-1 cell viability, migration and invasion. AKT phosphoryla- tion, MMP-9, and BCL-2 levels were all remarkably depressed in TFF3 knockdown TPC-1 cells. Using a thyroid papillary carcinoma xenograft mouse model, we further investigated the effects of TFF3 knockdown in vivo. Significantly delayed xenograft emerging, slower growth rate and lower final tumor weights and volumes were observed in the shTFF3 group as compared to the control group. As expected, the expression levels of MMP-9 and BCL-2 in the xenograft are consistent with those of shTFF3-TPC-1 and shTFF3-TPC-1 cells in vitro. Our results suggest that TFF3 plays a vital role in the viability and oncogenesis of TPC-1 cells and may be a potential target for effective treatment of thyroid papillary carcinoma.