Generation of a Liver Orthotopic Human Uveal Melanoma Xenograft Platform in Immunodeficient Mice

Summary

Orthotopic human liver metastatic uveal melanoma xenograft mouse models were created using surgical orthotopic implantation techniques with patient-derived tumor chunk and needle injection techniques with cultured human uveal melanoma cell lines.

Abstract

In recent decades, subcutaneously implanted patient-derived xenograft tumors or cultured human cell lines have been increasingly recognized as more representative models to study human cancers in immunodeficient mice than traditional established human cell lines in vitro. Recently, orthotopically implanted patient-derived tumor xenograft (PDX) models in mice have been developed to better replicate features of patient tumors. A liver orthotopic xenograft mouse model is expected to be a useful cancer research platform, providing insights into tumor biology and drug therapy. However, liver orthotopic tumor implantation is generally complicated. Here we describe our protocols for the orthotopic implantation of patient-derived liver-metastatic uveal melanoma tumors. We cultured human liver metastatic uveal melanoma cell lines into immunodeficient mice. The protocols can result in consistently high technical success rates using either a surgical orthotopic implantation technique with chunks of patient-derived uveal melanoma tumor or a needle injection technique with cultured human cell line. We also describe protocols for CT scanning to detect interior liver tumors and for re-implantation techniques using cryopreserved tumors to achieve re-engraftment. Together, these protocols provide a better platform for liver orthotopic tumor mouse models of liver metastatic uveal melanoma in translational research.

Introduction

Uveal melanoma is the most common intraocular malignant tumor among adults in the western world. During the past 50 years, the incidence of uveal melanoma (5.1 cases per million) has remained stable in the United States^1,2. Uveal melanoma arises from melanocytes in the iris, ciliary body, or choroid, and it is an extremely lethal disease when it develops metastasis. The death rate of patients with uveal melanoma metastasis was 80% at 1 year and 92% at 2 years after initial diagnosis of the metastases. The time between diagnosis of metastases and death is typically short, less than 6 months, without regards to ....

Protocol

Patients enrolled in the study should provide written consent allowing the use of discarded surgical samples for research purposes and genetic studies, according to an Institutional Review Board-approved protocol. This protocol was carried out in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health and approved by the Institutional Animal Care and Use Committee (IACUC).

1. Collection of Fresh Patient-derived Tumor.......

Discussion

The current orthotopic xenograft models are labor-intensive, time-consuming, and expensive to create. Orthotopic tumor xenograft mouse models for liver cancer were established more than two decades ago^19,20,21. However, this technique is complicated and requires use of special equipment, such as a micro-needle holder and 6-0 to 8-0 fine sutures under a microscope. Tumor and normal liver tissue must be sewn up carefully so that t.......

Materials

Name	Company	Catalog Number	Comments
Materials, tissues and animals
Buprenorphine
CO2 tank
Cryomedium
Exitron nano 12000 (Alkaline earth metal-based nanoparticle contrast agent)	Miltenyl Biotec	130-095-700
HBSS 1X, with calcium & magnesium	Corning	21-020-CM
Human liver metastatic uveal melanoma cell line
Human uveal melanoma tissue in the liver			All tissue handling should be done in a Biosafety Level 2 hood. Be careful when working with human tissue; always use gloves and avoid direct skin contact. Assume patients may have been infected with HIV or other highly transmissible organisms. Do not process samples known to carry infections.
Iodine
Isoflurane	Purdue Products	67618-150-17
Isopropanol	Fisher scientific	A416-1	Avoid direct contact to skin and eye and inhalation of anesthetic agent.
Liquid nitrogen
Matrigel HC	BD	354248
NOD.Cg-PrkdcscidIl2rgtm1Wjl/SzJ (NSG) mice	Jackson Lab	5557	4 to 8 weeks old
PBS 1X, without calcium and magnesium	Corning	21-031-CM
RPMI 1640	Corning	10-013-CV
Sterile alcohol prep pad (70% isopropyl alcohol)	Nice-Pak products	B603
4% paraformaldehyde phosphate buffer solution	Wako	163-20145
70% Ethyl alcohol solution	Fisher Scientific	04-355-122
Name	Company	Catalog Number	Comments
Equipments
Absorbable hemostat	Johnson and Johnson	63713-0019-61
Autoclave
Body weight measure
Cautery	Bovie Medical	MC-23009
Cell counter
Centrifuzer
Cotton swab
Cryo freezing container	NALGENE	5100-0001
Cryotube	SARSTEDT	72.379
Curved scissors	World Precision Instruments	503247
Curved ultrafine forceps	World Precision Instruments	501302
Fabric sheet
Freezer
F/AIR Filter Canister	Harvard Apparatus	600979
Heating pad
Isoflurane vaporizer	Artisan Scientific	66317-1
Liquid nitrogen
Liquid nitrogen jar	Thermo Fisher Scientific	2123
Micro-CT scan	Siemens
Needle holder	World Precision Instruments	501246
Petri dishes	Fisher Scientific	FB0875713
Pipette
Spray bottle
Sterile hood			Biosafety level 2 cabinet
Sterile No.11 scalpel	AD Surgical	A300-11-0
Straight forceps	World Precision Instruments	14226
Surgical drape
Tail vein restrainer	Braintree Scientific	TV-150-STD
Water bath
1 ml TB syringe with 27-gauge needle	BD	309623
1.7 ml tube	Bioexpress	C-3260-1
5-0 PDO Suture	AD Surgical	S-D518R13
15 mL conical tubes	AZER SCIENTIFIC	ES-9152N
27-gauge needle	BD	780301
27-gauge needle	Hamilton	7803-01
50 mL conical tubes	AZER SCIENTIFIC	ES-9502N
50 µl micro syringe	BD	80630
50 µl micro syringe	Hamilton	7655-01
100 mL container	Fisher Scientific	12594997
200μl tip