A preclinical, murine model of hepatic metastases performed via a hemispleen injection technique.
Numerous murine models have been developed to study human cancers and advance the understanding of cancer treatment and development. Here, a preclinical, murine pancreatic tumor model of hepatic metastases via a hemispleen injection of syngeneic murine pancreatic tumor cells is described. This model mimics many of the clinical conditions in patients with metastatic disease to the liver. Mice consistently develop metastases in the liver allowing for investigation of the metastatic process, experimental therapy testing, and tumor immunology research.
Pancreatic ductal adenocarcinoma (PDA) is the fourth leading cause of cancer related deaths in the United States1. The five year survival for patients with metastatic PDA is 2-12%1. Although adjuvant and neoadjuvant chemotherapy for pancreatic cancer is more effective today than ever, there still remains a desperate need for novel therapies.
The development of novel therapeutics necessitates reliable preclinical animal models. Although subcutaneous tumor models are straightforward to use, drawbacks include the inability of these tumors to metastasize and mimic the tumor progression and microenvironments seen in human cancers. Genetically engineered models, such as the genetically engineered mouse containing Kras and p53 knock-in oncogenic mutations (the KPC model)2 and the KPC model with a YFP lineage tracer (the PKCY model)3 allow for the study of naturally occurring tumors in immunocompetent mice. Additionally, the tumor microenvironment is unaltered and more closely resembles that seen in human tumor progression. Unfortunately, the timing of tumor development is variable within these models, which makes it difficult to study experimental therapies. Additionally, backcrossing of these mice requires a significant amount of time and financial commitment, which is not always feasible. Finally, implanted xenograft PDA mouse models necessitate immunocompromised mice, which have altered or absent tumor microenvironments. As a result, the efficacy of experimental therapies demonstrated in these preclinical models are often not reproducible in human clinical trials4.
This hemisplenectomy mouse model utilizes Panc02 tumor cells, which are a highly tumorigenic, methylcholanthrene induced pancreatic tumor cell line derived from C57BL/6 mice5,6. Additionally, other murine PDA cell lines derived from the KPC mice can be used in this model. Schulick et al. have previously developed a hemisplenectomy technique and created a syngeneic mouse model of colon cancer metastases7. This hemisplenectomy model (Figure 1) offers consistent and equal tumor inoculation in immunocompetent mice lending itself to the investigation of novel therapeutic agents7-10.
This preclinical murine model of pancreatic cancer metastasis to the liver via a hemispleen injection technique is the first model described that mirrors many of the clinical and immunological conditions of patients with metastatic disease to the liver. This model offers several advantages over other murine models. First, unlike transgenic models of pancreatic cancer in which only 30% of the mice develop metastases to the liver and the timing of metastases formation is quite variable, this model offers the advantage of c…
The authors have nothing to disclose.
KF and KO are co first authors along with KS
This work was supported in part by the AHPBA Fellowship (K.S.), NIH K23 CA148964-01 (L.Z.), Johns Hopkins School of Medicine Clinical Scientist Award (L.Z.), Viragh Foundation and the Skip Viragh Pancreatic Cancer Center at Johns Hopkins (E.M.J. and L.Z.), the National Pancreas Foundation (L.Z.), the Lefkofsky Family Foundation (L.Z.), the NCI SPORE in Gastrointestinal Cancers P50 CA062924 (E.M.J., L.Z.), the Lustgarten Foundation (L.Z.), and the Sol Goldman Pancreatic Cancer Center grants (K.S., B.H.E., L.Z.).
Cell culture media and components | will vary depending on cell line | ||
Phosphate Buffered Saline | Gibco by Life Technologies | 10010-023 | |
15 mL centrifigure tubes | Corning | 430052 | |
Curved Operating Scissor | Roboz Surgical Store | RS-6835 | |
Micro dissecting Graefe Forceps | Roboz Surgical Store | RS-5130 | |
Needle holder (regular) | World Precision Instruments, Inc | ||
3-0 or 4-0 suture | courtesy of dept of surgery, Johns Hopkins | ||
Weck Horizon Open Ligating Clip Applier, small, angled | Teleflex | 137085 | |
Weck Horizon Open Ligating Clip Applier, medium, angled | Teleflex | 237115 | |
Weck Horizon medium ligating clips | Teleflex | 002200 | |
Weck Horizon small ligating clips | Teleflex | 001200 | |
Syringe, 1 cc, tb syringe, 3/8" slip tip | Becton Dickinson | 309625 | |
Syringe, 1 cc, tb syringe, 5/8" slip tip | Becton Dickinson | 309597 | |
9 mm Autoclip Applier | Mikron | 427630 | |
9 mm Autoclip | Becton Dickinson | 427631 | |
Heating pad | Sunbeam | CAT93 | |
70% Ethanol | sold by numerous vendors | ||
Ketamine Hydrochloride | Hospira | 22395DD | |
Xylazine hydrochloride | Sigma | X1251 |