Abstract 2719: Development of bioluminescence orthotopic pancreatic-ductal-adenocarcinoma (PDAC) mouse models from primary PDAC cells as a new tool for therapeutic discovery.
Authors: Avan Amir , Caretti Viola , Funel Niccola , Galvani Elena , Lagerweij Tonny , Honeywell Richard J. , Boggi Ugo , Schuurhuis Gerrit Jan , Peters Godefridus J. , Würdinger Thomas , Giovannetti Elisa 
Published: August 2014

Pancreatic-ductal-adenocarcinoma (PDAC) remains a major unsolved health problem, and most drugs that successfully pass preclinical tests fail in the patients. The aim of this study was to establish orthotopic PDAC mice models from primary pancreatic tumor cells engineered for bioluminescent imaging as appropriate platform for development/screening of effective anticancer-drugs.

Early passages of four primary PDAC-cultures (PDAC-1, PDAC-2, PDAC-3 and PDAC-8) were successfully transduced with lentiviral vectors containing mCherry/Firefly-luciferase (Fluc), and CFP/Gaussia-luciferase (Gluc), as detected by fluorescence microscope and FACS analysis, and then injected orthotopically into the pancreas of at least 3 immunosuppressed athymic mice. The intensities of bioluminescence-signals (BLI), Fluc or Gluc, were monitored for 60 days by CCD camera and in blood samples, using Xenogen IVIS Lumina system and an illuminometer, respectively. In particular, BLI intensities of Fluc signals were increased within the range of 105-109 p/s/cm2/sr in PDAC-8 and 107-1011 p/s/cm2/sr in PDAC-2. Similarly, the Gluc signal in blood samples was increased overtime in all the developed PDAC-mouse-models. Additional imaging analyses to define tumor spatial characteristics were performed by magnetic resonance imaging (MRI) and Echo-Doppler.

Histopathological and immunohistochemical analyses were performed on paraffin-embedded slices of pancreas, as well as on metastatic lesions in liver, lungs and lymph nodes, while genetic characteristics of the xenografts were compared to the originator tumor and primary tumor cells using array-based comparative-genomic-hybridization (Agilent Human CGH Microarray 4x180K platform), in frozen specimens after laser-microdissection with the Leica LMD6000 instrument. These models presented extremely similar histopathological and genetics profile compared to their originator human tumors. The immunohistological analyses showed the overexpression of c-Met and phospho-c-Met in one tumor model (PDAC-3). Therefore, we tested the activity of the c-Met inhibitor crizotinib, alone or in combination with gemcitabine. Crizotinib significantly reduced tumor growth compared to untreated mice, while increasing gemcitabine concentrations, as monitored in blood and tissues samples with a LC-MS/MS validated method.

In conclusion, we developed orthotopic PDAC mice models enabled for bioluminescent imaging, showing similar genetic and histopathological features compared to their originator primary pancreatic tumors. Moreover, we demonstrated that these models provide a platform to monitor the effectiveness of targeted innovative anticancer drugs, representing a step toward personalized treatment in PDAC.

Citation Format: Amir Avan, Viola Caretti, Niccola Funel, Elena Galvani, Tonny Lagerweij, Richard J. Honeywell, Ugo Boggi, Gerrit Jan Schuurhuis, Godefridus J. Peters, Thomas Würdinger, Elisa Giovannetti. Development of bioluminescence orthotopic pancreatic-ductal-adenocarcinoma (PDAC) mouse models from primary PDAC cells as a new tool for therapeutic discovery. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2719. doi:10.1158/1538-7445.AM2013-2719