Prognostic value of apoptosis and apoptosis-associated proteins in salivary gland adenoid cystic carcinoma

The purpose of the present study was to investigate the level of apoptosis and expressions of p53, mdm2 and bcl-2 proteins in salivary gland adenoid cystic carcinoma (ACC) to determine potential relationships among apoptosis, apoptosis-associated proteins and clinical cumulative survival. Thirty-nine formalin-fixed, paraffin-embedded cases, cribriform (17), tubular (13) and solid (9), were studied by immunohistochemistry. Apoptosis detection and analysis were determined by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL). There was an inverse significance between the apoptotic index (AI) and bcl-2 expression (P = 0.018), whereas no correlation was found between the AI and either p53 or mdm2 expression (P = 0.416 and P = 0.456). Co-expression of p53 and mdm2 was found in 22 cases (P = 0.037). Patients with p53-positive tumors had a worse prognosis than those with p53-negative tumors (P = 0.014). Patients with a high AI had a better cumulative survival than patients with a low AI (P = 0.038). The present study suggests that p53 expression and AI can be useful as prognostic values; bcl-2 protein plays a role in the down-regulation of apoptosis and is also potentially useful as a prognostic parameter in salivary gland ACC.

Immunohistochemical analysis of centromere protein F expression in buccal and gingival squamous cell carcinoma

Centromere protein F (CENP-F) expression (localization and characteristics) in relation to tumor clinicopathological parameters was immunohistochemically examined and evaluated in 47 archival biopsy specimens of buccal and gingival squamous cell carcinomas (SCC). Centromere protein F expression was detected in 79% of the samples. An increase in the labeling index (LI) with WHO grading was obtained (P < 0.05). Correlations were obtained between the CENP-F LI and tumor size (P < 0.05). Immunoelectron microscopy showed CENP-F nuclear staining as punctate or fine dots. The present study shows that CENP-F expression and detection of a more specific cell subpopulation presents a theoretical advantage for the analysis of the precise cell cycle of G2 to M cells, compared to Ki-67.