The molecular basis of EPCAM expression loss in Lynch syndrome-associated tumors

• Verfasst von: Huth, Cathrin [VerfasserIn]
• Verfasst von: Kloor, Matthias [VerfasserIn]
• Verfasst von: Voigt, Anita Yvonne [VerfasserIn]
• Verfasst von: Bozukova, Gergana [VerfasserIn]
• Verfasst von: Evers, Christina [VerfasserIn]
• Verfasst von: Gaspar, Harald [VerfasserIn]
• Verfasst von: Tariverdian, Mirjam [VerfasserIn]
• Verfasst von: Schirmacher, Peter [VerfasserIn]
• Verfasst von: Knebel Doeberitz, Magnus von [VerfasserIn]
• Verfasst von: Bläker, Hendrik [VerfasserIn]
• Titel: The molecular basis of EPCAM expression loss in Lynch syndrome-associated tumors
• Verf.angabe: Cathrin Huth, Matthias Kloor, Anita Y. Voigt, Gergana Bozukova, Christina Evers, Harald Gaspar, Mirjam Tariverdian, Peter Schirmacher, Magnus von Knebel Doeberitz and Hendrik Bläker
• Umfang: 6 S.
• Fussnoten: Gesehen am 12.10.2018
• Titel Quelle: Enthalten in: Modern pathology
• Jahr Quelle: 2012
• Band/Heft Quelle: 25(2012), 6, S. 911-916
• ISSN Quelle: 1530-0285
• DOI: doi:10.1038/modpathol.2012.30
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1581869843

Abstract

Germline deletions affecting the Epithelial cell adhesion molecule (EPCAM) gene lead to silencing of MSH2 and cause Lynch syndrome. We have recently reported that lack of EPCAM expression occurs in many, but not all tumors from Lynch syndrome patients with EPCAM germline deletions. The differences in EPCAM expression were not related to the localization of EPCAM germline deletions. We therefore hypothesized that the type of the second somatic hit, which leads to MSH2 inactivation during tumor development, determines EPCAM expression in the tumor cells. To test this hypothesis and to evaluate whether lack of EPCAM expression can already be detected in Lynch syndrome-associated adenomas, we analyzed four carcinomas and two adenomas from EPCAM germline deletion carriers for EPCAM protein expression and allelic deletion status of the EPCAM gene region by multiplex ligation-dependent probe amplification. In four out of six tumors we observed lack of EPCAM expression accompanied bybiallelic deletions affecting the EPCAM gene. In contrast, monoallelic retention of the EPCAM gene was observed in the remaining two tumors with retained EPCAM protein expression. These results demonstrate that EPCAM expression in tumors from EPCAM deletion carriers depends on the localization of the second somatic hit that inactivates MSH2. Moreover, we report lack of EPCAM protein expression in a colorectal adenoma, suggesting that EPCAM immunohistochemistry may detect EPCAM germline deletions already at a precancerous stage.