RESUMO
The basal transcription of heme oxygenase-1 (HO-1) regulation is dependent upon a GT repeat germ line polymorphism (GTn) in the promoter of the HO-1 gene. We determined the prognostic value of HO-1 promoter polymorphism on the natural postoperative course of complete resected oesophageal cancer. Genomic DNA from 297 patients was amplified by polymerase chain reaction and sequenced. The results were correlated with clinicopathological parameters, disseminated tumour cells in bone marrow (DTC) and clinical outcome. Depending on short allele with <25 and long allele with ≥25, GTn repeats three genotypes (SS, SL and LL) were defined. A diverse role of GTn was evident in squamous cell carcinoma (SCC) and adenocarcinoma (AC). In SCC, the SS genotype presented less advanced tumours with lower rate DTC in bone marrow and relapse compared with L-allele carriers. In contrast, AC patients with the SS genotype displayed a complete opposing tumour characteristic. The disease-free (DFS) and overall survival (OS) in SCC patients was markedly reduced in LL genotypes (p < 0.001). In AC contrarily the SS genotype patients displayed the worst DFS and OS (p < 0.001). GTn is a strong prognostic factor with diverse prognostic value for recurrence and survival in AC and SCC.
Assuntos
Adenocarcinoma/genética , Carcinoma de Células Escamosas/genética , Neoplasias Esofágicas/genética , Heme Oxigenase-1/genética , Polimorfismo Genético , Regiões Promotoras Genéticas , Adenocarcinoma/patologia , Adenocarcinoma/cirurgia , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/cirurgia , Análise Mutacional de DNA , Intervalo Livre de Doença , Neoplasias Esofágicas/patologia , Neoplasias Esofágicas/cirurgia , Feminino , Heme Oxigenase-1/química , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Recidiva , Sequências Repetitivas de Ácido Nucleico , Resultado do TratamentoRESUMO
BACKGROUND: Transcriptional activity of the heme oxygenase-1 gene (HMOX-1) is modulated by a GTn-repeat promoter polymorphism. The long GTn-repeat allele has been previously reported to be associated with increased risk of oral squamous cell carcinoma (OSCC) in male areca chewer and short GTn-repeat allele has been proposed to have protective properties in OSCC patients. The aim of the present study was to correlate the GTn-repeat genotypes with clinicopathological characteristics along with clinical outcome of non-areca chewer OSCC patients. METHODS: DNA of 99 patients that underwent complete surgical resection of OSCC was analyzed for GTn-repeat polymorphism in the HMOX-1 promoter by polymerase chain reaction, capillary electrophoresis and DNA sequencing. RESULTS: Seven SS (7.1%), 51 SL (51.5%) and 41 LL (41.4%) genotypes were found. In a total of 14 (14.1%) patients, tumor recurrence (TR) was observed. There was no TR in the SS allele carriers. In SL carriers three and in LL 11 TR occurred (P = 0.009, chi-squared test). Mean relapse-free survival was 109.2 months in SL allele carriers compared with 72.3 months in LL allele carriers (P = 0.01, log-rank test). Multivariate Cox regression modeling identified GTn-repeat genotype as an independent prognostic factor (P = 0.03; relative risk (RR) 4.1; 95% CI 1.1-14.6). CONCLUSION: Presence of S allele was associated with a lower TR rate and better relapse-free survival in OSCC patients. HMOX-1 promoter polymorphism might be considered as a potential prognostic marker in OSCC patients.
