Expression of p73 in Non-small Cell Lung Carcinomas

ABSTRACT

BACKGROUND: The p73 is a recently identified homologue of the tumor suppressor gene, p53, and it has been found to induce apoptosis and inhibit cell proliferation. However, its role in the development of tumors is unclear. This study examined the expression of p73 in patients with non-small cell lung carcinomas (NSCLCs) to determine its clinical significance and association with the expressions of p53, pRb, and mdm2. METHODS: A total of 183 NSCLCs were analyzed immunohistochemically using a tissue microarray. RESULTS: The p73 protein was expressed in the cell nuclei in 156 (85.2%) out of the 183 cases. There was no correlation between the p73 expression and the clinicopathological variables. However, there was a correlation between the p73 expression and the mdm2 and pRb expressions. Multivariate Cox survival analysis identified tumor size and lymph node metastasis to be independent prognostic factors, but the p73 expression was not found to be associated with the patients' survival. CONCLUSIONS: p73 is commonly expressed in NSCLC and it might, in conjunction with pRb and mdm2, be involved in the development of these tumors.