RESUMO
Alcohol drinking is a leading risk factor for the development of esophageal squamous cell carcinoma (ESCC). However, the molecular mechanisms of alcohol-associated ESCC remain poorly understood. One of the most commonly mutated genes in ESCC is nuclear factor erythroid 2 like 2 (NFE2L2 or NRF2), which is a critical transcription factor regulating oxidative stress response and drug detoxification. When NRF2 is hyperactive in cancer cells, however, it leads to metabolic reprogramming, cell proliferation, chemoradioresistance, and poor prognosis. In this study, hyperactive NRF2 was found to up-regulate acetyl-CoA synthetase short-chain family members 2 (ACSS2), an enzyme that converts acetate to acetyl-CoA, in ESCC cells and mouse esophagus. We also showed that knockdown of NRF2 or ACSS2 led to decreased ACSS2 expression, which in turn reduced the levels of acetyl-CoA and ATP with or without ethanol exposure. In addition, ethanol exposure enhanced lipid synthesis in ESCC cells. Moreover, we observed a change in the metabolic profile of ESCC cells exposed to ethanol as a result of their NRF2 or ACSS2 status. We further showed that ACSS2 contributed to the invasive capability of NRF2high ESCC cells exposed to ethanol. In conclusion, the NRF2/ACSS2 axis mediates the metabolic effect of alcohol drinking on ESCC.
Assuntos
Acetato-CoA Ligase/metabolismo , Consumo de Bebidas Alcoólicas/efeitos adversos , Reprogramação Celular , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas do Esôfago/patologia , Lipogênese , Fator 2 Relacionado a NF-E2/metabolismo , Acetato-CoA Ligase/genética , Animais , Proliferação de Células , Neoplasias Esofágicas/etiologia , Neoplasias Esofágicas/metabolismo , Carcinoma de Células Escamosas do Esôfago/etiologia , Carcinoma de Células Escamosas do Esôfago/metabolismo , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch/genética , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Camundongos , Camundongos Knockout , Fator 2 Relacionado a NF-E2/genéticaRESUMO
PAX9 is a transcription factor of the PAX family characterized by a DNA-binding paired domain. Previous studies have suggested a potential role of PAX9 in squamous cell differentiation and carcinogenesis of the oro-oesophageal epithelium. However, its functional roles in differentiation and carcinogenesis remain unclear. In this study, Pax9 deficiency in mouse oesophagus promoted cell proliferation, delayed cell differentiation, and altered the global gene expression profile. Ethanol exposure downregulated PAX9 expression in human oesophageal epithelial cells in vitro and mouse forestomach and tongue in vivo. We further showed that PAX9 was downregulated in human oro-oesophageal squamous cell carcinoma (OESCC), and its downregulation was associated with alcohol drinking and promoter hypermethylation. Moreover, ad libitum feeding with a liquid diet containing ethanol for 40 weeks or Pax9 deficiency promoted N-nitrosomethylbenzylamine-induced squamous cell carcinogenesis in mouse tongue, oesophagus, and forestomach. In conclusion, PAX9 regulates squamous cell differentiation in the oro-oesophageal epithelium. Alcohol drinking and promoter hypermethylation are associated with PAX9 silencing in human OESCC. PAX9 downregulation may contribute to alcohol-associated oro-oesophageal squamous cell carcinogenesis. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Assuntos
Diferenciação Celular , Transformação Celular Neoplásica/metabolismo , Neoplasias Esofágicas/metabolismo , Carcinoma de Células Escamosas do Esôfago/metabolismo , Fator de Transcrição PAX9/metabolismo , Fatores de Transcrição Box Pareados/metabolismo , Carcinoma de Células Escamosas de Cabeça e Pescoço/metabolismo , Neoplasias da Língua/metabolismo , Consumo de Bebidas Alcoólicas/efeitos adversos , Animais , Linhagem Celular , Proliferação de Células , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/patologia , Metilação de DNA , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas do Esôfago/genética , Carcinoma de Células Escamosas do Esôfago/patologia , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator de Transcrição PAX9/genética , Fatores de Transcrição Box Pareados/deficiência , Fatores de Transcrição Box Pareados/genética , Regiões Promotoras Genéticas , Fatores de Risco , Transdução de Sinais , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Neoplasias da Língua/genética , Neoplasias da Língua/patologia , TranscriptomaRESUMO
Kenya belongs to a high incidence region known as Africa's esophageal cancer (EC) corridor. It has one of the highest incidence rates of EC worldwide, but research on EC in Kenya has gone highly unnoticed. EC in Kenya is unique in its high percentage of young cases (< 30 years of age). In this review, we show the current status of EC in the country. We mainly focus on significant risk factors such as alcohol drinking, genetic factors, malnutrition and hot food/drink. Future directions in the study and prevention of EC in Kenya are also discussed.