Fig. 6: HN1L-AP-2γ-PLK1 axis promotes ESCC progression via up-regulation of Cyclin D1 and Slug.

A AP-2γ transcriptional binding sites in the PLK1 gene promoter. B Luciferase reporter assay showed that HN1L transcriptionally up-regulated PLK1 expression by activating AP-2γ in KYSE30 cells. C ChIP-qPCR assay to validate that AP-2γ bound to the promoter of PLK1 in Vector or HN1L-transfected KYSE30 cells. D Co-IP was performed with HN1L antibody on KYSE30-HN1L cells. E Double IF staining with antibodies against HN1L and AP-2γ in KYSE30-HN1L cells. F, G The rescue experiments on cell proliferation (F) and metastasis (G) mediated by PLK1 were performed in AP-2γ-silenced KYSE150 cell. H The protein levels of Cyclin D1 and Slug in KYSE30 cells after HN1L overexpression were analyzed with western blotting. I The protein levels of Cyclin D1 and Slug in KYSE30 cells after HN1L overexpression or PLK1 inhibitor BI-2536 treatment were analyzed with western blotting. J The diagram shows that HN1L enhances PLK1 expression by activating transcription factor AP-2γ, which further increases Cyclin D1 and Slug expression levels, promoting ESCC cell proliferation, metastasis and drug resistance. In B, C, E, F, data are presented as the mean ± SD; two-sided Student’s t test; *P < 0.05, **P < 0.01, ***P < 0.001, ns: no significant difference.