Radiofrequency ablation for dysplasia in Barrett's esophagus restores β-catenin activation within esophageal progenitor cells
| Autor: | Rebecca B. Katzman, Ramanarao Dirisina, Preetika Sinh, Kumar Krishnan, Jeffrey Z. Ko, Srinadh Komanduri, Linheng Li, John D. Cluley, Terrence A. Barrett |
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| Rok vydání: | 2011 |
| Předmět: |
Adult
Pathology medicine.medical_specialty Physiology Radiofrequency ablation Blotting Western Epithelium law.invention Barrett Esophagus Esophagus law medicine Humans Progenitor cell Phosphorylation beta Catenin business.industry Stem Cells Gastroenterology medicine.disease Immunohistochemistry surgical procedures operative medicine.anatomical_structure Dysplasia Barrett's esophagus Catenin Catheter Ablation Tumor Suppressor Protein p53 business therapeutics Proto-Oncogene Proteins c-akt |
| Zdroj: | Digestive diseases and sciences. 57(2) |
| ISSN: | 1573-2568 |
| Popis: | Endoscopic therapies for Barrett's esophagus (BE) associated dysplasia, particularly radiofrequency ablation (RFA), are popular alternatives to surgery. The effect of such therapies on dysplastic stem/progenitor cells (SPC) is unknown. Recent studies suggest that AKT phosphorylation of β-Catenin occurs in SPCs and may be a marker of activated SPCs. We evaluate the effect of RFA in restoring AKT-mediated β-Catenin signaling in regenerative epithelium.Biopsies were taken from squamous, non-dysplastic BE, dysplastic BE and esophageal adenocarcinoma (EAC). Also, post-RFA, biopsies of endoscopically normal appearing neosquamous epithelium were taken at 3, 6, and 12 months after successful RFA. Immunohistochemistry and Western blot analysis was performed for Pβ-Catenin(552) (Akt-mediated phosphorylation of β-Catenin), Ki-67 and p53.There was no difference in Pβ-Catenin552 in squamous, GERD, small bowel and non-dysplastic BE. There was a fivefold increase in Pβ-Catenin(552) in dysplasia and EAC compared to non-dysplastic BE (P0.05). Also, there was a persistent threefold increase in Pβ-Catenin(552) in neosquamous epithelium 3 months after RFA compared to native squamous epithelium (P0.05) that correlated with increased Ki-67. Six months after RFA, Pβ-Catenin(552) and Ki-67 are similar to native squamous epithelium.Enhanced AKT-mediated β-Catenin activation is seen in BE-associated carcinogenesis. Three months after RFA, squamous epithelial growth from SPC populations exhibited increased levels of Pβ-Catenin(552). This epithelial response becomes quiescent at 6 months after RFA. These data suggest that elevated Pβ-Catenin(552) after RFA denotes a repair response in the neosquamous epithelium 3 months post-RFA. |
| Databáze: | OpenAIRE |
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