RESUMO
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.
Assuntos
Carcinoma de Células Escamosas/genética , Inibidor p16 de Quinase Dependente de Ciclina/genética , Neoplasias Laríngeas/genética , Mutação/genética , Proteína Supressora de Tumor p53/genética , Carcinoma de Células Escamosas/diagnóstico , DNA de Neoplasias/genética , Feminino , Genes Neoplásicos/genética , Neoplasias de Cabeça e Pescoço/genética , Humanos , Neoplasias Laríngeas/diagnóstico , Masculino , Pessoa de Meia-Idade , Prognóstico , Análise de Sequência de DNARESUMO
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.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Carcinoma de Células Escamosas/genética , Inibidor p16 de Quinase Dependente de Ciclina/genética , Metilação de DNA , Metilases de Modificação do DNA/genética , Enzimas Reparadoras do DNA/genética , Proteínas Quinases Associadas com Morte Celular/genética , Neoplasias Laríngeas/genética , Proteínas Nucleares/genética , Proteínas Supressoras de Tumor/genética , Adulto , Idoso , Bulgária , Carcinoma de Células Escamosas/patologia , Feminino , Humanos , Neoplasias Laríngeas/patologia , Masculino , Pessoa de Meia-Idade , Proteína 1 Homóloga a MutL , Prevalência , Regiões Promotoras GenéticasRESUMO
BACKGROUND: Recurrent respiratory papillomatosis (RRP) is a rare manifestation of human papilloma virus (HPV) infection with extremely high relapse frequency, poorly understood immunopathogenesis, and lack of efficient treatment. Immunotherapy with Calgevax (BCG) in combination with CO2 surgery significantly improves the outcome of RRP. The present study investigates cellular immunity parameters in RRP patients, and the effects of 20-month Calgevax immunomodulation. MATERIALS AND METHODS: RRP patients (n = 15) subjected to combined therapy were tested before, 6, 12 and 20 months after the start of immunomodulation. Absolute counts and percentage of T, B and NK cells, effector T1 (CD8 + IFNgamma+); Th1 (CD4+IFNgamma+), Th17 (CD4+IL-17+) and regulatory (CD4+FoxP3+) T lymphocytes, as well as the in vitro stimulated secretion of IL-2, IL-4, IL-5, IL-10, IFNgamma and TNFalpha were determined by flow cytometry (FACSCanto II, BD). RESULTS: While no significant changes were detected in the circulating T, B and NK subsets, RRP patients presented increased proportions of Tc1, Th1 and Th17 cells, and significantly reduced IFNgamma/IL-4 and IFNgamma/IL-10 ratios as compared to healthy controls (15% vs. 8%), (58 vs. 139 and 15 vs. 26, respectively), p < 0.05 for all comparisons. Increased Treg (9% vs. 4%), and decreased Th17 effectors share (0.7% vs. 0.4%) were observed at 12 months, while IFNgamma/IL-4 and IFNgamma/IL-10 ratios were restored after 20 months of Calgevax application. CONCLUSIONS: Antiviral response closely depends on cytokine background. Calgevax potentiates Treg differentiation at the expense of proinflammatory Th17, limits hyperactivation and virus-specific T cell clones depletion, and restores a Th1 cytokine background.