SUZ 12 is a novel putative oncogene promoting tumorigenesis in head and neck squamous cell carcinoma

The suppressor of zest 12 ( SUZ 12), one of the core polycomb repressive complex 2 ( PRC 2) components, has increasingly appreciated as a key mediator during human tumorigenesis. However, its expression pattern and oncogenic roles in head and neck squamous cell carcinoma ( HNSCC ) remain largely unexplored yet. Here, we sought to determine its expression pattern, clinicopathological significance and biological roles in HNSCC . Through data mining and interrogation from multiple publicly available databases, our bioinformatics analyses revealed that SUZ 12 mRNA was significantly overexpressed in multiple HNSCC patient cohorts. Moreover, SUZ 12 protein was markedly up‐regulated in primary HNSCC samples from our patient cohort as assessed by immunohistochemical staining and its overexpression significantly associated with cervical node metastasis and reduced overall and disease‐free survival. In the 4‐nitroquinoline 1‐oxide (4 NQO )‐induced HNSCC mouse model, increased SUZ 12 immunostaining was observed along with disease progression from epithelial hyperplasia to squamous cell carcinoma in tongue. Furthermore, sh RNA ‐mediated SUZ 12 knock‐down significantly inhibited cell proliferation, migration and invasion in HNSCC cells, and resulted in compromised tumour growth in vivo. Collectively, our data reveal that SUZ 12 might serve as a putative oncogene by promoting cell proliferation, migration and invasion, and also a novel biomarker with diagnostic and prognostic significance for HNSCC .