Investigation of ZNF148 function in squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is a progressive and invasive tumor originating from the oral cavity and is among the most common cancers. HNSCC is characterized by immunosuppression, which supports uncontrolled cancer progression by suppressing the anti-tumoral response. In this context, pro-inflammatory cytokines and interferon pathways play a pivotal role in promoting cancer immune escape. Cancer cells can also support tumor growth by altering the expression of ZNF148, a member of the zinc-finger DNA-binding family. ZNF148 is important for cell growth and proliferation under both physiological and pathological conditions. To understand the function of ZNF148 in tumorigenesis, we analyzed the expression of this transcription factor in various human cancers. We found that ZNF148 is significantly overexpressed and shows genomic amplification in HNSCC. Transcriptome analyses revealed that ZNF148-activated genes are part of the type I and II interferon signaling pathways. Consequently, we focused on the role of ZNF148 in the inflammatory response in HNSCC. Our data demonstrated that type I interferon genes are predominantly downregulated by ZNF148 knockdown. Integrating RNA-seq data with genome-wide ZNF148 DNA binding sites, we observed an enrichment for the interferon α (IFNα) pathway. We found a positive correlation between ZNF148 expression and type I interferon signalling genes in highly inflamed HNSCC samples. To assess the impact of ZNF148 as a transcriptional regulator of type I interferon genes, we conducted experiments under IFNαstimulated conditions. We showed that ZNF148 silencing significantly impaired the expression of MX1, an example of an interferon stimulated gene (ISG). Additionally, we discovered that ZNF148 binds to the MX1 promoter region, thereby promoting its expression and facilitating the inflammatory response. IFNα signaling induces the association of STAT1, STAT2, and IRF9 complex to activate ISGs. We observed that ZNF148 is crucial for maintaining STAT1 nuclear import. Furthermore, ZNF148 knockdown affected the relative mRNA expression of two STAT1 targets, OASL and IFI27, suggesting that ZNF148 modulates STAT1 transcriptional activity. Interestingly, STAT1 nuclear import requires binding with importin subunit alpha-5 (KPNA1) and importin subunit beta-1 (KPNB1) transporters. Upon IFNα stimulation, we noted that ZNF148 slightly modulates KPNA1 and KPNB1 expression. In conclusion, our results suggest a novel role for ZNF148 in the inflammatory context of HNSCC. This work proposes ZNF148 as a new modulator of type I inflammatory response genes in human cancer. Future experiments will elucidate novel therapeutic approaches for targeting HNSCC.