RESUMO
PURPOSE: The endothelins are a family of three highly conserved and homologous vasoactive peptides that are expressed across all organ systems. Endothelin (Edn) dysregulation has been implicated in a number of pathophysiologies, including diabetes and diabetes-related complications. Here we examined Edn2 and endothelin receptor B (Endrb) expression in retinae of diabetic mouse models and measured serum Edn2 to assess its biomarker potential. MATERIALS AND METHODS: Edn2 and Ednrb mRNA and Edn2 protein expression were assessed in young (8wk) and mature (24wk) C57Bl/6 (wild type; wt), Kimba (model of retinal neovascularisation, RNV), Akita (Type 1 diabetes; T1D) and Akimba mice (T1D plus RNV) by qRT-PCR and immunohistochemistry. Edn2 protein concentration in serum was measured using ELISA. RESULTS: Fold-changes in Edn2 and Ednrb mRNA were seen only in young Kimba (Edn2: 5.3; Ednrb: 6.0) and young Akimba (Edn2: 7.9, Ednrb: 8.8) and in mature Kimba (Edn2:9.2, Ednrb:11.2) and mature Akimba (Edn2:14.0, Ednrb:17.5) mice. Co-localisation of Edn2 with Müller-cell-specific glutamine synthetase demonstrated Müller cells and photoreceptors as the major cell types for Edn2 expression in all animal models. Edn2 serum concentrations in young Kimba, Akita and Akimba mice were not elevated compared to wt. However, in mature mice, Edn2 serum concentration was increased in Akimba (6.9pg/mg total serum protein) compared to wt, Kimba and Akita mice (3.9, 4.6, and 3.8pg/mg total serum protein, respectively; p<0.05). CONCLUSIONS: These results demonstrated that long-term hyperglycaemia in conjunction with VEGF-driven RNV increased Edn2 serum concentration suggesting Edn2 might be a candidate biomarker for vascular changes in diabetic retinopathy.
Assuntos
Diabetes Mellitus Tipo 1/diagnóstico , Endotelina-2/genética , Hiperglicemia/diagnóstico , Receptor de Endotelina B/genética , Neovascularização Retiniana/diagnóstico , Fator A de Crescimento do Endotélio Vascular/genética , Animais , Biomarcadores/sangue , Glicemia/metabolismo , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/patologia , Modelos Animais de Doenças , Endotelina-2/sangue , Células Ependimogliais/metabolismo , Células Ependimogliais/patologia , Expressão Gênica , Hemoglobinas Glicadas/metabolismo , Hiperglicemia/sangue , Hiperglicemia/genética , Hiperglicemia/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos , Células Fotorreceptoras de Vertebrados/metabolismo , Células Fotorreceptoras de Vertebrados/patologia , RNA Mensageiro/sangue , RNA Mensageiro/genética , Receptor de Endotelina B/sangue , Neovascularização Retiniana/sangue , Neovascularização Retiniana/genética , Neovascularização Retiniana/patologia , Fator A de Crescimento do Endotélio Vascular/sangueRESUMO
BACKGROUND: Detection of hypermethylated circulating tumor DNA has the potential to be a minimally invasive, low cost, and reproducible method for cancer detection. METHODS: We evaluated serum from 100 patients with known head and neck squamous cell carcinoma (HNSCC) and 50 healthy control patients for 3 previously described methylation targets, endothelin receptor type B (EDNRB), cyclin-dependent kinase inhibitor 2A (CDKN2A or p16), and deleted in colorectal carcinoma (DCC), using quantitative methylation specific polymerase chain reaction (qMSPCR). RESULTS: EDNRB hypermethylation was identified in the serum of 10% of the patients with HNSCC but in none of the control patients. DCC hypermethylation was detected in 2 serum samples from patients with cancer that also amplified EDNRB and one of these samples also had p16 hypermethylation. EDNRB hypermethylation was statistically significant by Fisher's exact test (p = .03) when comparing HNSCC to controls. CONCLUSIONS: Serum EDNRB hypermethylation is a highly specific but not sensitive serum biomarker for HNSCC.