Abstract 5324: Cathepsin E expression: A new potential target for pancreatic tumor imaging

Abstract

Abstract Purpose: Pancreatic ductal adenocarcinoma (PDAC) shows unique high expression of Cathepsin E (CTSE). Here we assessed the usefulness of detecting CTSE activity in vivo as a prognostic biomarker for PDAC using mouse xenografts and transgenic models of PDAC. Procedures: CTSE expression in human and mouse pancreases with/without cancer were assessed by immunohistochemistry. Transgenic animal models of PDAC and xenografts of primary human PDAC tumors or establish pancreatic cancer cell lines in nude mice were injected with the CTSE selective fluorescent probe via tail vein. CTSE expressions in transgenic pancreatic tumors and xenografts were imaged using IVIS-100 optical imaging system. Negative control tumors were imaged in parallel. Tumors, organs and tissues of interest were imaged ex vivo for their associated Cath E expression. Data: Results confirmed the over expression of CTSE in pancreatic cancer patients and transgenic mouse models of pancreatic cancer. Images illustrate the capability of detecting CTSE expression within pancreatic tumors in both transgenic and xenograft mice models. In vivo and ex vivo images of PDAC were possible by targeting CTSE expression. Conclusions: Results represent the usefulness of CTSE as a potential molecular target for pancreatic cancer imaging. The elevated CTSE expression in pancreatic tumors allows in vivo detection of human PDAC xenografts and ex vivo imaging of transgenic PDAC tumors in mice. The study demonstrates CTSE as a promising target for tumor imaging. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5324. doi:10.1158/1538-7445.AM2011-5324