Krt15

Samples were embedded in paraffin and cut into 5-μm-thick sections. The primary antibodies against the following proteins were used: Sox4, Krt10, invulcrin, AE13 (all diluted 1:100, Santa Cruz, USA), Krt14 (1:50, Sangon Biotech, China), Krt15 (1:50, Sangon Biotech, China), AE15 (1:100, Abcam, USA), BrdU (1:200, Abcam, USA), BMP6 (1:100, Abcam, USA) and Wnt10b (1:100, Abcam, USA). Cy3-labeled or AF488-labeled secondary antibodies (Beyotime, China) were used. The sections were counterstained with DAPI (Beyotime, China). Finally, the sections were mounted with anti-fade mount media (Beyotime, China) and observed under a microscope.

DPCs were seeded into 60 mm dishes at a density of 1 × 10⁶ cells per dish. Forty-eight hours after viral infection, the cells were washed twice with cold PBS and then lysed with RIPA buffer (Beyotime, Shanghai, China). Cell lysates were collected and the protein concentration was measured with a BCA protein assay (Beyotime, Shanghai, China). Subsequently, the protein was separated by SDS-PAGE and transferred to a PVDF membrane. The membrane was then blocked with 5% non-fat milk in TBS, and incubated overnight at 4°C with diluted primary antibodies. The primary antibodies were as follows: GAPDH, c-myc, survivin, CyclinD1, IGF-1, HGF, VEGF (R&D Systems, Minneapolis, MN, United States), Twist1 (Santa Cruz, CA, United States), KRT40 (Santa Cruz, CA, United States), MSX2 (Santa Cruz, CA, United States), KRT5 (Sangon, Shanghai, China), KRT15 (Sangon, Shanghai, China), and FGF7 (Boster, Wuhan, China). After washing, the membrane was incubated with HRP-labeled secondary antibodies. A Bio-Rad imaging system was used to collect and quantify images.