Clinicopathologic and genetic studies of nasal NK/T-cell lymphoma: 2. Mutations of the p53, β-catenin, and ras genes

Abstract

The p53 is a well-known tumor suppressor gene that causes cell with damaged DNA to arrest cell cycle or promote apoptosis. Ras gene is a well-known oncogene, and its function is to switch from an inactive GDP-bound state to an active GTP-bound state after ligand interaction of a variety of extra cellular receptors. β-Catenin originally has a role in E-cadherin-mediated cell–cell adhesion, but its stabilization plays important role in carcinogenesis. There are many reports about mutations of the genes in various malignancies, but few report in nasal NK/T-cell lymphoma (N-NKTL). In this study, we analyzed mutations of the p53 and β-catenin gene in 32 cases of nasal NK/T-cell lymphoma.The CD56 or EBER-1 positive lymphoma cells were dissected from tissue section using laser capture micro dissection. Genomic DNA corresponding to p53, ras and beta-catenin gene were amplified by polymerase chain reaction (PCR), and gene mutations were detected by direct sequencing.As a result of this study, missense mutations of p53 gene were observed in four cases, those of ras gene in one case, and those of β-catenin gene in two cases. Patients with p53 gene mutation showed significantly shorter survival as compared to patients without mutation.Therefore, p53 gene mutation may be important for predisposing to clinical course in nasal NK/T-cell lymphoma.