Tumor protein D52 is upregulated in oral squamous carcinoma cells under hypoxia in a hypoxia-inducible-factor-independent manner and is involved in cell death resistance

Abstract Background Tumor protein D52 (TPD52) reportedly plays an important role in the proliferation and metastasis of various cancer cells, including oral squamous cell carcinoma (OSCC) is expressed strongly at center tumor, where microenvironment hypoxic. Thus, present study investigated roles TPD52 survival death OSCC cells under hypoxia, relationship with hypoxia-inducible factor (HIF). We examined expression hypoxic conditions analyzed effects HIF on modulation expression. Finally, combinational knockdown inhibition were both vitro vivo. Results The mRNA levels increased hypoxia. However, increase was independent transcription. Importantly, observation due to upregulation stability by binding T-cell intercellular antigen (TIA) 1 TIA-related (TIAR). Simultaneous significantly reduced viability. In addition, vivo tumor-xenograft experiments showed that acts as autophagy inhibitor caused a decrease p62. Conclusions This increases hypoxia HIF-independent manner concordance HIF, suggesting novel therapeutics might be led suppression.