Cystatin A Down-regulation in Head and Neck Squamous Cell Carcinoma Cell Lines Decreases Cancer Hallmark Signatures

Background Cystatin A (CSTA), an endogenous inhibitor of lysosomal cysteine protease, is expressed primarily in epithelial tissues. The expression of CSTA was found to be dysregulated in various cancers and associated with cancer pathogenesis, but its role is reported to be contradictory. Our previous preliminary study found CSTA to be upregulated in the saliva and tissues of patients with head and neck squamous cell carcinoma (HNSCC). In this current study, we have explored the role of CSTA in the pathophysiology of HNSCC.