Immunohistochemical Analyses of PTC and Tumor Tissues

IHC analyses of tissues were conducted as described in previous study [17 (link), 23 (link)]. Briefly, PTC tissue sections were incubated with an antibody to PELI1 (12,053–1-AP, diluted 1: 200; Proteintech, Rosemont, IL); mice tumor sections were incubated with an antibody to Ki-67 (ab16667, diluted 1: 200; Abcam, Cambridge, MA) or MMP2 (10,373–2-ap, diluted 1: 200; Proteintech) overnight at 4 °C, followed incubating by HPR-conjugated secondary antibody. Diaminobenzidine was used as the substrate. The nuclei were counterstained with hematoxylin. All pictures were captured using a Nikon microscope. Integrated optical density of Ki-67 and MMP2 in mice tumor sections were measured by using Image-Pro Plus software (Version X; Adobe, San Jose, CA).