The stromal immunoexpression of CLIC4 may be related to the difference in the biological behavior between oral squamous cell carcinoma and oral verrucous carcinoma

BACKGROUND: Oral squamous cell carcinoma (OSCC) has high morbidity and mortality rates while oral verrucous carcinoma (OVC), an uncommon variant of OSCC, exhibits a distinct biological behavior. CLIC4 protein plays a role in the cell cycle and apoptosis regulation and participates in the myofibroblasts transdifferentiation process, which are the main cells of the tumor stroma. This study analyzed the immunoexpression of CLIC4 and α-SMA in 20 OSCC cases and 15 OVC cases. MATERIAL AND METHODS: A semiquantitative analysis of CLIC4 and α-SMA immunoexpression was performed in the parenchyma and stroma. Nuclear and cytoplasmic reactivity was analyzed separately for the CLIC4 immunostaining. The data were submitted to Pearson's chi-square and Spearman's correlation tests (p ≤ 0.05). RESULTS: In the CLIC4 analysis, there was a significant difference in the immunoexpression of this protein between OSCC and OVC stroma (p < 0.001). It was observed a higher expression of α-SMA in the OSCC stroma. There was a positive and significant correlation between CLIC4 and α-SMA immunoexpression in the OVC stroma (r = 0,612; p = 0,015). CONCLUSIONS: The decrease or absence of nuclear CLIC4 immunoexpression in the neoplastic epithelial cells and the increase of its expression in the stroma may influence the difference in biological behavior between OSCC and OVC. Key words:Squamous cell carcinoma, verrucous carcinoma, CLIC4, myofibroblasts.