BACKGROUND: The DNA-binding protein p63, a member of the p53 family, regulates differentiation and proliferation of epithelial progenitor cells. In this study, we evaluated the expression of p63 in lung cancer to gain insight into the pathogenesis of these processes. METHODS: A total of 89 patients who had undergone potentially curative surgery for lung cancer were selected. Expressions of p53, p63, and deltaNp63 were analyzed immunohistologically using a tissue array method with formalin-fixed, paraffin-embedded specimens. Immunohistological results were then correlated with clinicopathological parameters with prognostic implications. RESULTS: Expressions of p63 and deltaNp63 were found in 47 (52.8%) and 38 (43.2%) of the 89 patients, respectively. No relationships between the p63 or deltaNp63 expressions and any clinicopathological variables were found. p63 was expressed in 92.5% (37/40) of the squamous cell carcinomas, 17.9% (7/39) of the adenocarcinomas, 20% (1/5) of the small cell carcinomas, and 0% (0/5) of the large cell carcinomas. deltaNp63 was expressed in 92.3% (36/39) of the squamous cell carcinomas, 2.5% (1/39) of the adenocarcinomas, 0% (0/5) of the small cell carcinomas, 0% (0/5) of the large cell carcinomas, and 50% (1/2) of the adenosquamous cell carcinomas. In the squamous cell carcinomas, significantly high expressions of p63 and deltaNp63 were found (p<0.05). p53 protein was detected in samples from 49 of the 89 patients (55.1%). No significant associations between the p53 expressions and the p63 or deltaNp63 expressions were noted. CONCLUSION: p63 or deltaNp63 is likely to be involved in the development of squamous cell carcinomas of the lung and no significant association was found between p63 or deltaNp63 and patient survival rates.
Adenocarcinoma ; Carcinoma, Large Cell ; Carcinoma, Small Cell ; Carcinoma, Squamous Cell ; Humans ; Lung Neoplasms* ; Lung* ; Stem Cells ; Survival Rate