Histone deacetylase-1 and -2 expression in mobile tongue squamous cell carcinoma: associations with clinicopathological parameters and patients survival.

BACKGROUND: Histone deacetylases (HDACs) have been associated with tumor development and progression in several types of human malignancy and HDAC inhibitors are currently being explored as anti-cancer agents in clinical trials. The aim of the present study was to evaluate the clinical significance of HDAC-1 and -2 protein expression in mobile tongue squamous cell carcinoma (SCC).

METHODS: HDAC-1 and -2 protein expression was assessed immunohistochemically on 49 mobile tongue SCC tissue samples and was analyzed in relation with clinicopathological characteristics, overall and disease-free patients' survival.

RESULTS: HDAC-1 overexpression was significantly associated with younger patients' age (P = 0.0381) and male gender (P = 0.0345), poor histopathological grade of differentiation (P = 0.0236) and the presence of lymph node metastases (P = 0.0104). Intense HDAC-1 staining intensity was significantly associated with male gender (P = 0.0127), increased stromal infiltration reaction (P = 0.0125) and well-defined shape of tumor invasion (P = 0.0396). HDAC-2 overexpression did not show significant correlations with any clinicopathological parameters, whereas intense HDAC-2 staining intensity was significantly associated with the presence of muscular invasion (P = 0.0466) and advanced depth of invasion (P = 0.0251). Mobile tongue SCC patients with HDAC-1 overexpression presented shorter overall and disease-free survival compared to those with no evidence of HDAC-1 overexpression (log-rank test, P = 0.0651 and 0.0247, respectively).

CONCLUSIONS: The present study supported evidence that HDACs may participate in the formation and progression of mobile tongue SCC, reinforcing their possible use as biomarkers as also the therapeutic utility of HDAC inhibitors in mobile tongue SCC chemoprevention and treatment.