Nuclear localization of mammary serine protease inhibitor (MASPIN): is its impact on the prognosis in laryngeal carcinoma due to a proapoptotic effect?

PURPOSE:Cell death by apoptosis is considered a regulator of cell number; cancer cells are defective in their response to apoptosis. Many potential markers of apoptosis are under study: M30 immunoreactivity is confined to the cytoplasm of apoptotic epithelial cells and is expressed during early apoptosis. Mammary serine protease inhibitor (MASPIN), a suppressor of tumor growth, seems to be involved in the induction of tumour cell apoptosis. The aim of our preliminary study was to investigate, for the first time, the relations between MASPIN subcellular pattern of expression, nuclear MASPIN expression, M30 expression, and prognosis in laryngeal carcinoma. MATERIALS AND METHODS: Subcellular pattern of distribution of MASPIN and nuclear MASPIN expression were immunohistochemically determined in 66 consecutive cases of laryngeal carcinoma. M30 expression in correspondent carcinoma fields was also calculated. RESULTS: M30 expression was significantly higher in the group of laryngeal carcinomas with MASPIN nuclear localization (P = .024). Our investigation found a reduced carcinoma recurrence rate in the group of patients with MASPIN nuclear localization (P value = .0086). The log-rank test showed a significantly longer disease-free interval in patients with nuclear MASPIN localization (P = .029). CONCLUSIONS: These preliminary results support the hypothesis of an apoptosis-sensitizing effect of nuclear MASPIN in laryngeal carcinoma with the potential perspective of a clinical use of the tumour suppressive proapoptotic function of MASPIN.