RESUMEN
Laryngeal squamous cell carcinoma (LSCC) is the second most common tumour of the head and neck. It is characterized by frequent aberrations in two cell-cycle regulators--CDKN2A and TP53. However, LSCC has been often studied as a part of the group of head and neck cancers and not as an individual entity. In the current study we aimed to examine mutation status of CDKN2A and TP53 genes in 108 LSCC patients. DNA was extracted from fresh-frozen tumour tissues; exons 1-3 of CDKN2A and exons 5-8 of TP53 were screened for mutations by direct sequencing. Genetic aberrations in CDKN2A were found in 16 (14.2%) and those in TP53--in 56/108 (51.9%) tumours. Seven mutations (two insertions, three deletions, one missense and one silent) detected in CDKN2A were not described previously. Also, we found seven novel deletions and a novel indel in TP53. No significant associations with clinical features were found. However, TP53 mutations were predominantly observed in smokers with advanced stage tumours. Screening for genetic aberrations in a defined group of LSCC contributes to the knowledge about laryngeal carcinogenesis. Further investigations are required to confirm the observed trends in associations with clinical features.
Asunto(s)
Carcinoma de Células Escamosas/genética , Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , Neoplasias Laríngeas/genética , Mutación/genética , Proteína p53 Supresora de Tumor/genética , Carcinoma de Células Escamosas/diagnóstico , ADN de Neoplasias/genética , Femenino , Genes Relacionados con las Neoplasias/genética , Neoplasias de Cabeza y Cuello/genética , Humanos , Neoplasias Laríngeas/diagnóstico , Masculino , Persona de Mediana Edad , Pronóstico , Análisis de Secuencia de ADNRESUMEN
BACKGROUND: Laryngeal squamous cell carcinoma (laryngeal SCC) is a frequently occurring cancer of the head and neck area. Epigenetic changes of tumor-related genes contribute to its genesis and progression. METHODS: We assessed promoter methylation status of the selected genes (CDKN2A, MGMT, MLH1, and DAPK) using methylation-sensitive high resolution melting (MS-HRM) in 100 patients with laryngeal SCC and studied the correlations with clinical characteristics. RESULTS: The prevalence of promoter methylation in MGMT, CDKN2A, MLH1, and DAPK was 59 of 97 (60.8%), 46 of 97 (47.4%), 45 of 97 (46.4%), and 41 of 97 patients (42.3%), respectively. Significantly increased methylation of CDKN2A was observed in heavy smokers. Epigenetic inactivation of CDKN2A and MLH1 were found to be associated with lymph node involvement. An inverse correlation was present between MLH1 methylation and alcohol consumption. CONCLUSION: Our results strongly suggest that deregulation of p16-associated, and MLH1-associated pathways, because of promoter hypermethylation, is associated with increased cancer cell migration, tumor invasiveness, and, thus, aggressive phenotype.