P53 mutations in keratocystic odontogenic tumour

Abstract

AbstractAim: The abrogation of the function for the tumour suppressor gene p53 has been suggested as one of the most common genetic alterations in neoplasia. We evaluated p53 mutations, clinico‐pathological and immunohistochemical findings in patients with sporadic keratocystic odontogenic tumours (KCOTs).Material and methods: A total of 32 patients with KCOT treated surgically were enrolled in this study. We performed mutation analysis of p53 using archival formalin‐fixed paraffin‐embedded tissue. The immunohistological technique was employed to identify TP53 expression. P53 mutations in exons 5–8 were evaluated by direct sequencing. These results were compared with the characteristics of each tumour.Results: Forty‐four percent of the cysts showed overexpression of TP53. P53 mutations were detected in 10 cases (31.3%) of 32 KCOTs; two cases within exon 5, two cases within exon 8, five cases within exon 7 and one case in both exons 5 and 7. Five missense mutations (R248G, D247K, Q136R, V272M, V143A) and four silence mutations (138A, 158R, 247D, 279G,) were detected. P53 mutation was detected in two (50%) out of four recurrence cases and eight (28.5%) out of 28 non‐recurrence cases (P = 0.572). R248G mutation was the most common in KCOTs (15.6%). We did not detect any remarkable associations of these cases carrying p53 mutations to clinico‐pathological and immunohistochemical characteristics.Conclusion: The results implied that the p53 gene alterations are involved in the development of KCOT.