Evaluation of caspase-3 and caspase-8 deregulation in tongue squamous cell carcinoma, based on immunohistochemistry and computerised image analysis

Aims: To investigate the potential role of caspase-3 and caspase-8 protein expression in the biological behaviour of tongue squamous cell carcinoma. Materials and methods: We conducted immunohistochemical analyses of 87 specimens of primary tongue squamous cell carcinoma, using monoclonal anti-caspase-3 and anti-caspase-8 antibodies. A digital image analysis assay was also performed in order to evaluate the results. Results: Reduced expression of caspase-8 and -3 proteins was observed in 30/87 (34.5 per cent) and 79/87 (90.5 per cent) cases, respectively. Cox regression analysis showed no prognostic significance for the association between overall protein expression of either marker and survival probability (p = 0.174 for caspase-3; p = 0.608 for caspase-8). Interestingly, the size of the examined tumours was strongly correlated with survival status (p = 0.024). Conclusions: Simultaneous deregulation of caspase-8 and -3 is a frequent event in tongue squanlous cell carcinoma. Activation of caspase-3, which is predominantly down-regulated, may be a crucial process for induction of apoptosis and response to therapeutic strategies.