Search

p53gene mutation is not a frequent event in the tumorigenesis of lymphomas and the expression of p53 protein is independent ofp53gene mutations. The present study aimed to investigate mutations in thep53gene in a series of extranodal B-cell lymphomas, and its association with p53 protein expression. A total of 52 cases were graded histologically into Grade 1, Grade 2 and Grade 3 tumors and p53 protein expression was detected using immunohistochemistry. Mutations in thep53gene were analyzed using polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) and mobility shifts were confirmed by direct sequencing. The tumors comprised 26 (50%) Grade 1, 9 (17%) Grade 2 and 15 (29%) Grade 3. A high proportion of Grade 2 (25%) tumors expressed p53 protein (P = 0.051) and carriedp53gene mutation (33%) (P = 0.218). However, p53 protein expression was not associated withp53gene mutations (P = 0.057). Transversion mutations (88%) were more frequently detected than transition mutations (12%). The present study revealed thatp53gene mutations and p53 protein expression occurred in higher frequencies in Grade 2 tumors, which may be of pathogenetic importance. The high frequency of transversion mutations may reflect the influence of an etiological agent in the tumorigenesis of mucosa-associated lymphoid tissue (MALT lymphoma). [ABSTRACT FROM AUTHOR]