Immunohistochemical and molecular analysis of BAX, BCL-2 and p53 genes in laryngeal squamous cell carcinomas

Background: We investigated the role of apoptosis and its potential alterat ions in laryngeal squamous cell carcinomas (LSCCs) by evaluating bax, bcl-2 and p53 protein expression in 50 cases and by characterising the molecular status of the bar and p53 genes. Material and Methods: p53 and bar gene mu tations were investigated by means of PCR/SSCP and direct DNA sequencing, a nd bar, bcl-2 and p53 protein expression by means of immunohistochemistry. Results: We identified p53 gene mutations in 17/50 cases (34%); p53 express ion in 26 of the 50 cases (52%); bcl-2 expression in 5/50 cases (10%); bar expression in 32/47 cases (68%). 18/33 cases with a wild type p53 gene over expressed p53 protein: 12 cases (approximate to 66%) were bax+/bcl-2-. Of t he remaining cases without p53 protein expression, seven cases (approximate to 47%) were bax+/bcl-2-. Conclusions: Our observations suggest that the o verexpression of p53 may contribute to the repression bf bcl-2 and the indu ction of bar expression in LSCCs. However, the fact that a number of cases not expressing p53 did not present any clear up-regulation of bax or down-r egulation of bcl-2 suggests that bcl-2 and bar may be regulated by various mechanisms other than p53.