Details

Autor(en) / Beteiligte

• Mullen, Matthew G.
• Newhook, Timothy E.
• Lindberg, James M.
• Adair, Sara J.
• Blais, Edik M.
• Michaels, Alex D.
• Stelow, Edward B.
• Papin, Jason A.
• Parsons, J. Thomas
• Bauer, Todd W.

Titel

Abstract A47: A patient-derived xenograft model of pancreatic cancer in mice to develop novel adjuvant therapies

Ist Teil von

• Cancer research (Chicago, Ill.), 2016-04, Vol.76 (7_Supplement), p.A47-A47

Erscheinungsjahr

2016

Link zum Volltext

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Abstract Background: Eighty percent of patients with pancreatic ductal adenocarcinoma (PDAC) die from their disease within five years of surgical resection, likely due to presence of occult metastases at diagnosis. We have developed a patient-derived xenograft (PDX) model in mice to investigate the behavior of occult metastatic cells in the liver microenvironment and derive novel adjuvant therapies. Methods: Five PDAC tumors (215, 366, 608, 654 and 738) were resected from patients and implanted orthotopically in mice. Tumors were harvested, cell lines generated and transduced with luciferase, then injected into spleens of mice to generate microscopic liver metastases, then primary tumors removed via splenectomy. Bioluminescence imaging of mice and histologic analysis and flow cytometry of livers were utilized to characterize each tumor's distinct pattern of cell clearance and outgrowth kinetics. Affymetrix gene expression of tumors was performed. Mice were treated with adjuvant therapy following resection of primary tumors in the spleen and time-to-progression (TTP) and overall survival (OS) were measured. Results: Each PDX cell line demonstrated unique and reproducible clearance in the liver and outgrowth kinetics as measured by bioluminescence imaging. Distinct differences in gene expression were identified in tumors exhibiting rapid vs. delayed outgrowth. The MEK inhibitor trametinib (0.3 mg/kg oral daily) prolonged TTP and OS vs. control (OS - Tumor 608: 114 vs. 43 days, p<0.001; Tumor 366: MS not achieved vs. 167 days, p=0.0488). In a randomized preclinical trial, sequential therapy with gemcitabine followed by trametinib provided a survival advantage and increased TTP when compared with control and single agent gemcitabine treatment. Conclusions: This PDX PDAC model of occult metastasis allows characterization of hepatic clearance of tumor cells and outgrowth kinetics. Metastatic outgrowth appears to be dependent upon distinguishable tumor cell-specific factors. Trametinib effectively inhibits KRAS-MEK-ERK signaling, delays outgrowth of occult metastases and prolongs survival of mice. Utilization of this model will help further define the complex interaction of PDAC cells and the metastatic microenvironment of the liver. Citation Format: Matthew G. Mullen, Timothy E. Newhook, James M. Lindberg, Sara J. Adair, Edik M. Blais, Alex D. Michaels, Edward B. Stelow, Jason A. Papin, J. Thomas Parsons, Todd W. Bauer. A patient-derived xenograft model of pancreatic cancer in mice to develop novel adjuvant therapies. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Metastasis; 2015 Nov 30-Dec 3; Austin, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(7 Suppl):Abstract nr A47.