Fig 2: TFAP2B promoted thyroid cancer cell growth via the COX-2 signaling pathway in vivo.a TFAP2B knockdown suppressed thyroid cancer cell growth in a mouse xenograft. Images of the thyroid cancer cell tumor xenograft from each mouse (n = 7 mice/group). e TFAP2B overexpression promoted thyroid cancer cell growth in a mouse xenograft, but suppressed by COX-2 inhibitor celecoxib when feeded to mice. Images of the thyroid cancer cell tumor xenograft from each mouse (n = 5 mice/group). b, f Tumor volumes were analyzed. *P < 0.05. c, g Tumor weights were recorded and analyzed. *P < 0.05. d, h The expression of TFAP2B and COX-2 in tumor tissues was analyzed by immunohistochemistry (IHC) staining

Fig 3: TFAP2B promoted thyroid cancer cell proliferation and clonogenicity via the COX-2 signaling pathway in vitro.a Cell proliferation and clonogenicity were suppressed by downregulating TFAP2B in TPC-1 cell line. b Cell proliferation and clonogenicity were promoted by upregulating TFAP2B in KTC-1 cell line. c, d Cell proliferation was suppressed by COX-2 inhibitor celecoxib; overexpression of TFAP2B promoted the expression of COX-2 and increased thyroid cancer cell proliferation, which was reversed by COX-2 knockdown or COX-2 inhibitor celecoxib in TPC-1 and BCPAP cell line. *P < 0.05 (n = 3). e, f Overexpression of TFAP2B promoted the thyroid cancer cell clonogenicity, which was reversed by COX-2 knockdown or COX-2 inhibitor celecoxib in TPC-1 and BCPAP cell line. *P < 0.05 (n = 3)

Fig 4: TFAP2B regulates thyroid cancer cell migration, invasion and cell apoptosis via the COX-2 signaling pathway in vitro.a Knockdown of TFAP2B inhibited the cell migration and invasion in TPC-1 cells. b Knockdown of COX-2 reversed the promotion of cell migration and invasion by TFAP2B overexpression in BCPAP cells. c Cell apoptosis was measured by Annexin-V/PI assays in TFAP2B overexpression BCPAP cells (with or without COX-2 knockdown, 60 µM celecoxib, n = 3), histograms indicated subpopulation of cells positive for Annexin V/PI

Fig 5: TFAP2B was identified as a COX-2 promoter-binding protein in thyroid cancer cells.a Binding of TFAP2B on the 5'-biotin-labeled COX-2 promoter probe or a nonspecific probe (NSP) was detected by western blot using anti-TFAP2B antibody in thyroid cancer cell lines (BCPAP, TPC-1, KTC-1, K2). b Relative COX-2 promoter activity in TFAP2B knockdown BCPAP cells and TFAP2B overexpress K2 cells (n = 3). c COX-2 protein expression was upregulated in TFAP2B overexpressed TPC-1 cells, and relative COX-2 mRNA level was upregulated in TFAP2B overexpressed TPC-1 cells (n = 3). c COX-2 protein expression was downregulated in TFAP2B knockdown TPC-1 cells, and relative COX-2 mRNA level was downregulated in TFAP2B knockdown TPC-1 cells (n = 3)