A Syngeneic Mouse Model of Metastatic Renal Cell Carcinoma for Quantitative and Longitudinal Assessment of Preclinical Therapies

Summary

Implementation of an orthotopic model of renal cell carcinoma in immunocompetent mice affords the investigator a clinically-relevant system defined by the presence of a primary renal tumor and lung metastases in the same animal. This system can be used to preclinically test a variety of treatments in vivo.

Abstract

Renal cell carcinoma (RCC) affects > 60,000 people in the United States annually, and ~ 30% of RCC patients have multiple metastases at the time of diagnosis. Metastatic RCC (mRCC) is incurable, with a median survival time of only 18 months. Immune-based interventions (e.g., interferon (IFN) and interleukin (IL)-2) induce durable responses in a fraction of mRCC patients, and multikinase inhibitors (e.g., sunitinib or sorafenib) or anti-VEGF receptor monoclonal antibodies (mAb) are largely palliative, as complete remissions are rare. Such shortcomings in current therapies for mRCC patients provide the rationale for the development of novel treatment protocols. A key component in the preclinical testing of new therapies for mRCC is a suitable animal model. Beneficial features that recapitulate the human condition include a primary renal tumor, renal tumor metastases, and an intact immune system to investigate any therapy-driven immune effector responses and the formation of tumor-induced immunosuppressive factors. This report describes an orthotopic mRCC mouse model that has all of these features. We describe an intrarenal implantation technique using the mouse renal adenocarcinoma cell line Renca, followed by the assessment of tumor growth in the kidney (primary site) and lungs (metastatic site).

Introduction

Renal cell carcinoma (RCC) accounts for the majority of malignant kidney neoplasms and roughly 3% of all adult malignancies worldwide^1,2. Due to lack of symptoms, misdiagnosis, and insufficient screening tools for RCC, almost 30% of patients will present with metastatic RCC (mRCC) at the time of diagnosis, with an additional 20-30% of patients progressing to a metastatic stage². These cases result in ~13,500 deaths annually^1,3. Though earlier detection and treatment of primary RCC has improved, the rate of RCC-related death cont....

Protocol

The following protocol describes an experimental procedure for inducing and monitoring the growth of experimental orthotopic renal tumors and any potential spontaneous metastases. All of the following procedures are done in accordance with institutional policies and approved procedures regarding the humane use of experimental animals.

1. Maintenance of Cell Lines

1. Maintain murine renal adenocarcinoma cell line, Renca, in Roswell Park Memorial Institute (RPMI) 1640 medium supplemented with 10% fetal calf serum (FCS), 1% penicillin-streptomycin, and 1 mM each of non-essential amino acids, L-glutamine, and sodium pyruvate (referred to as complete RPMI).....

Results

The successful implantation of Renca cells will result in tumor development in the kidney and metastasis to the lungs of the mice. After the excision of the tumor-bearing and the contralateral kidneys, wet tissue weights (g) were measured to demonstrate the tumor burden based on increased weight (Figure 1). Renca tumors can be identified by immunohistochemistry through cytokeratin 8 and 18 staining (Figure 2). For longitudinal studies, a luciferase-expres.......

Discussion

We present a protocol for an orthotopic RCC mouse model. Implantation of mouse renal adenocarcinoma tumor cells into the mouse kidney provides a clinically-relevant model of mRCC. This model results in a primary tumor within the kidney and distant metastasis in the lungs, both of which are hallmarks of advanced RCC. The description presented herein is specific for the Renca cell line in immunocompetent Balb/c mice. Using this orthotopic model, we have shown that the Renca tumors are responsive to immunotherapy, demonstra.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Artificial tears ophthalmic ointment	Akorn	NDC 17478-162-35
Vetbond Tissue Adhesive	3M	CBGBIW011019
Betadine Solution (Povidone-iodine, 5%)	Purdue Products, L.P.	NDC 67618-155-32
0.25% Marcaine (bupivavaine HCl injection)	Hospira	0409-1587-50
Heating pad	Sunbeam
Syringes	BD	309659
Gauze	Venture	908291
Ketamine	Phoenix Pharmaceuticals	NDC 57319-609-02
Xylazine	Akorn	NDC 59399-111
Hank’s Balanced Salts	Sigma-Aldrich	H2387
IVIS	Caliper
D-Luciferin, Potassium Salt	GoldBio	LUCK-1G
India Ink	Chartpak Inc	44201
Scissors
Forceps
Sleeping Beauty (SB) transposon system	Neuromics	SBT0200
Renca	ATCC	CRL-2947