Original Article
Copyright ©2014 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jul 28, 2014; 20(28): 9476-9485
Published online Jul 28, 2014. doi: 10.3748/wjg.v20.i28.9476
Establishment of an orthotopic pancreatic cancer mouse model: Cells suspended and injected in Matrigel
Yong-Jian Jiang, Chong-Lek Lee, Qiang Wang, Zhong-Wen Zhou, Feng Yang, Chen Jin, De-Liang Fu
Yong-Jian Jiang, Chong-Lek Lee, Qiang Wang, Feng Yang, Chen Jin, De-Liang Fu, Department of Pancreatic Surgery, Huashan Hospital, Fudan University, Shanghai 200040, China
Zhong-Wen Zhou, Department of Pathology, Huashan Hospital, Fudan University, Shanghai 200040, China
Author contributions: Jiang YJ designed this study and wrote the first draft of the manuscript; Jiang YJ and Lee CL performed the experiments; Wang Q and Yang F analyzed the data; Zhou ZW reviewed all HE and immunohistochemical staining of the tumor specimens sections; Jin C and Fu DL critically reviewed the manuscript.
Supported by The Shanghai Municipal Natural Science Foundation, No. 11ZR1405500; and the Shanghai Municipal Science and Technology Commission grant, No. 13140902401
Correspondence to: De-Liang Fu, MD, PhD, Department of Pancreatic Surgery, Huashan Hospital, Fudan University, No. 12, Urumqi Middle Road, Shanghai 200040, China. surgeonfu@163.com
Telephone: +86-21-52887164 Fax: +86-21-52888277
Received: October 31, 2013
Revised: March 24, 2014
Accepted: April 5, 2014
Published online: July 28, 2014
Abstract

AIM: To establish an orthotopic mouse model of pancreatic cancer that mimics the pathological features of exocrine pancreatic adenocarcinoma.

METHODS: Pan02 cells were suspended in low-temperature Matrigel and injected into the parenchyma of pancreatic tails of C57BL/6 mice, with cells suspended in phosphate buffered saline (PBS) serving as a control. Primary and implanted tumors were confirmed pathologically. The rate of tumor formation and intraperitoneal implantation in the two groups were compared at different time points after injection. Leakage and intra-abdominal dispersion of Matrigel and PBS, both dyed with methylene blue, were compared after injection into the parenchyma of the pancreas. We observed adherence and proliferation in Pan02 cells suspended in Matrigel in vitro. We also compared the pathological manifestation of this orthotopic pancreatic cancer model in the head and tails of the pancreas. The characteristics of the origin of epithelial cells and exocrine markers of established orthotopic pancreatic tumors were confirmed using immunohistochemistry.

RESULTS: Diluted Matrigel could form a gel drip in the pancreatic parenchyma, effectively preventing leakage from the injection site and avoiding dispersion in the abdominal cavity. Pan02 cells were able to adhere to a dish, proliferate, and migrate in the gel drip. The tumor formation rate in the Matrigel group was 100% at both 2 and 3 wk after injection, whereas it was 25.0% and 37.5% in the PBS group at 2 and 3 wk, respectively (P < 0.05). The intraperitoneal tumor implantation rate was 75.0% in the PBS group after 3 wk of injection, while it was 12.5% in the Matrigel group (P < 0.05). Hepatoduodenal ligament and duodenal invasions with obstructive jaundice and upper digestive obstruction with mesenteric lymph node metastasis were observed in the pancreatic head group. In the pancreatic tail group, spleen and gastric invasion were dominant, leading to retroperitoneal lymph nodes metastasis. Positive immunohistochemical staining of cytokeratin and negative staining of vimentin and chromogranin A confirmed that the orthotopic pancreatic tumor injected with Pan02 cells suspended in Matrigel was of epithelial origin and expressed exocrine markers of cancer.

CONCLUSION: This method of low-temperature Matrigel suspension and injection is effective for establishing an orthotopic mouse model of pancreatic cancer.

Keywords: Pancreatic cancer, Orthotopic mouse model, Matrigel, C57BL/6 mouse, Pan02

Core tip: This article describes a simple and effective method to establish an orthotopic pancreatic cancer model in immunocompetent mice. The orthotopic pancreatic cancer models in the pancreatic head and tail both effectively mimic the relative pathological features of exocrine adenocarcinoma of the human pancreas. This model system will provide a platform for exploring new research outcomes for the effective treatment and management of pancreatic cancer.