Immunohistochemical Expressions of p16 and p21 Proteins in Laryngeal Squamous Cell Carcinomas / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Cyclin-dependent kinase inhibitor (CDKI) is known to play an important role in oncogenesis, but its clinical effect in head and neck cancer has not been reported yet. This study was designed to investigate the prognostic relevance of p16 and p21 protein expressions by evaluating the correlation between the expression pattern of p16 and p21 proteins, and tumor progress in laryngeal squamous cell carcinoma. MATERIALS AND METHODS: Paraffin-embedded tissue specimens from 54 patients, who were diagnosed with laryngeal squamous cell carcinoma between 1993 and 2002, were immunohistochemically stained for p16 and p21 proteins. The clinical features from these patients were retrospectively evaluated. The percentages of positive nuclei that stained positive for tumor were determined. RESULTS: In p16 protein, the proportion of strong expression was higher than that of weak expression in early tumor stage (T1, T2) and clinical stages (stage I, II): the proportion of weak expression was higher in the advanced tumor stage (T3, T4) and the clinical stages (stage III, IV): the correlations between the expressions of p16 protein and tumor clinical stages were significant (p0.05). In p16 and p21 protein, the proportion of weak expression was higher in nodal stage with neck metastasis than in nodal stage without neck metastasis: but the correlation between expression of p16 or p21 protein and nodal stage was not significant, respectively (p>0.05). CONCLUSION: There was a significant correlation between weak expression of p16 protein and more advanced tumor clinical stages. The expression of p16 protein may have prognostic value restrictively in laryngeal squamous cell carcinoma. Further study will be needed to understand the role of p16 and p21 protein in oncogenesis of laryngeal squamous cell carcinoma.

An Immunohistochemical Study of p53, Cyclin D1 and Cathepsin D Expression in Sinonasal Tumors / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Various host and tumor parameters, particularly the tumor size and lymph node metastasis have been studied in an attempt to evaluate and decide the optimal treatment of the patients with head and neck carcinomas. Moreover, it has been recognized that prognostic parameters can be useful for the evaluation of biological behaviors of malignancy. The p53 is a tumor suppressor gene and cyclin D1 is a cell cycle regulator, essential for G1 phase progression. Cathepsin D is a lysosomal aspartyl endopeptidase which degrades the extracellular matrix and proteoglycan. But there are still controversy in their clinical meanings in sinonasal malignant tumors. The purpose of this study is to assess the roles of p53, cyclin D1 and cathepsin D in sinonasal tumorigenesis. MATERIALS AND METHOD: 27 inverted papilloma (IPs), 5 IPs associated with malignant transformation, and 16 squamous cell carcinoma tissue specimens were investigated by immunohistochemical staining for p53, cyclin D1, and cathepsin D. Clinicopathologic values were compared with the incidence of p53, cyclin D1, cathepsin D expression in sinonasal malignant tumors. RESULTS: p53/cyclin D1 expressions were increased as tumor progressed and these expressions were statistically significant (p< .05). No significant correlations were found among p53, cyclin D1, cathepsin D and other clinicopathologic factors. CONCLUSION: These data suggest that expressions of p53, cyclin D1 and cathepsin D may play an important role in the tumorigenesis and progression of sinonasal malignant tumor sequence. Also, it is suggested that p53/cyclin D1 expressions may be useful variables for the prognostic assessment of sinonasal malignant tumors. However, it is not enough conclude so based on this result alone. Further studies, such as using molecular biological techniques, will be required to determine that p53/cyclin D1 expressions are related to the development or prognosis of sinonasal malignant tumors.