Transarterial Administration of Oncolytic Viruses for Locoregional Therapy of Orthotopic HCC in Rats

Summary

Oncolytic virotherapies are under development as novel therapeutics for the treatment of hepatocellular carcinoma (HCC). Here we describe a method for locoregional therapy of HCC via hepatic arterial administration of oncolytic virus.

Abstract

Hepatocellular carcinoma (HCC) is a disease with limited treatment options and poor prognosis. In recent years, oncolytic virotherapies have proven themselves to be potentially powerful tools to fight malignancy. Due to the unique dual blood supply in the liver, it is possible to apply therapies locally to orthotopic liver tumors, which are predominantly fed by arterial blood flow. We have previously demonstrated that hepatic arterial delivery of oncolytic viruses results in safe and efficient transduction efficiency of multifocal HCC lesions, resulting in significant prolongation of survival in immune competent rats. This procedure closely mimics the application of transarterial embolization in patients, which is the standard palliative care provided to many HCC patients. The ability to administer tumor therapies through the hepatic artery in rats allows for a highly sophisticated preclinical model for evaluating novel viral vectors under development. Here we describe the detailed protocol for microdissection of the hepatic artery for infusion of oncolytic virus vectors to treat orthotopic HCC.

Introduction

Hepatocellular carcinoma (HCC) is the fifth most prevalent cancer worldwide, and the third leading cause of cancer-related death, making it a significant health concern^1,2. For patients who are not eligible for tumor resection, or those awaiting liver transplantation, locoregional therapy involving transarterial embolization (TAE) or transarterial chemoembolization (TACE) are applied as standard palliative care^3,4. These therapies exploit the unique feature of dual blood supply in the liver whereby tumors are fed almost exclusively by hepatic arterial blood flow, while the surrounding liver receives the majority of its blood supply from the porta....

Protocol

Note: The following steps have been performed in accordance with the guidelines of our institution and the local government of Bavaria, Germany. All attempts to reproduce this protocol must be made in adherence with the local guidelines for the humane treatment of animals, as dictated by local animal care and use committee. For example, many institutes require that sterile gloves are worn during rodent surgery. Furthermore, work with viruses must be performed according to local regulations, taking care for personal and environmental safety. Care must be taken to properly dispose of contaminated waste and to clean instruments and workspace (i.e., by autoc....

Results

With experience, a nearly 100% success rate (meaning that the artery was successfully dissected and injected, and the animal survived surgery) can be achieved. However, the health status of the rat prior to surgery (degree of tumor burden, underlying liver function, etc.) will obviously play a role in the outcome of the surgical intervention. Following surgery, rats can be expected to experience transient weight loss and a slight, transient elevation of liver enzymes, even if buf.......

Discussion

Although direct intratumoral injection is undoubtedly the simplest method to result in efficient tumor transduction of a single tumor nodule, hepatic arterial infusion represents an ideal administration route to target multifocal, orthotopic HCC. This method has proven to be both safe and effective for treating HCC in immune competent rats with oncolytic viruses. Furthermore, since HCC patients are routinely treated by transarterial application of chemoembolization, the method described here is readily translatable to .......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Veterinary clippers	Aesculap	GT415	Small, cordless trimmer ideal for removing fur from surgical area
Stereomicroscope	Zeiss	Stemi SV6
30 G Needles	Braun	4656300	30 G x ½”
1 ml syringes	Braun	9161406V	Tuberculin syringe
Disposable scalpel	Feather	2975#15	#15 blade
Standard surgical scissors	Fine Science Tools	14001-13	Sharp/blunt, for opening skin and muscle
Adson forcep	Fine Science Tools	1101-12	With teeth, for grasping skin and muscle
Alm retractor	Fine Science Tools	17008-07	With blunt teeth, for spreading abdominal cavity open during surgery
Gauze swabs	Lohmann & Rauscher	18504	7.5 cm x 7.5 cm, should be autoclaved prior to use
Cotton-tipped applicator swabs	Lohmann & Rauscher	11970	Sterile
Fine-tipped foreceps	Fine Science Tools	11063-07	0.4 mm, angled tip, for dissecting hepatic artery
Vannas spring scissors	Fine Science Tools	91500-09	For delicate cutting
Micro-needle holder	Fine Science Tools	12076-12	For ligating gastroduodenal artery
Needle holder	Fine Science Tools	12005-15	Tungsten carbide jaws
7-0 Prolene sutures	Ethicon	8648H	Polypropylene suture with curved needle, for ligating gastroduodenal artery
4-0 Vicryl sutures	Ethicon	V3040H	With curved needle attached
Infrared warming lamp	Beurer	IL11	For maintaining body temperature post-operatively