Establishment of Gastric Cancer Patient-derived Xenograft Models and Primary Cell Lines

Summary

The current protocol describes methods to establish patient-derived xenograft (PDX) models and primary cancer cell lines from surgical gastric cancer samples. The methods provide a useful tool for drug development and cancer biology research.

Abstract

The use of preclinical models to advance our understanding of tumor biology and investigate the efficacy of therapeutic agents is key to cancer research. Although there are many established gastric cancer cell lines and many conventional transgenic mouse models for preclinical research, the disadvantages of these in vitro and in vivo models limit their applications. Because the characteristics of these models have changed in culture, they no longer model tumor heterogeneity, and their responses have not been able to predict responses in humans. Thus, alternative models that better represent tumor heterogeneity are being developed. Patient-derived xenograft (PDX) models preserve the histologic appearance of cancer cells, retain intratumoral heterogeneity, and better reflect the relevant human components of the tumor microenvironment. However, it usually takes 4-8 months to develop a PDX model, which is longer than the expected survival of many gastric patients. For this reason, establishing primary cancer cell lines may be an effective complementary method for drug response studies. The current protocol describes methods to establish PDX models and primary cancer cell lines from surgical gastric cancer samples. These methods provide a useful tool for drug development and cancer biology research.

Introduction

Gastric cancer is the fifth-most common cancer worldwide and the third leading cause of cancer death. In 2018, over 1,000,000 new cases of gastric cancer were diagnosed globally, and an estimated 783,000 people were killed by this disease¹. The incidence and mortality of gastric cancer remain very high in northeastern Asian countries^2,3. Despite significant progress in the field of cancer therapeutics, the prognosis of patients with advanced gastric cancer remains poor, with a five-year survival rate of approximately 25%^4,5....

Protocol

This human study was approved by the Institutional Ethics Review Board of Sun Yat-sen University Cancer Center (SYSUCC, Guangzhou, China). The animal study was approved by the Institutional Animal Care and Use Committee of Sun Yat-sen University. Note: all experiments were performed in compliance with the relevant laws and institutional guidelines, including the Guideline for occupational exposure protection against blood-borne pathogens.

1. Sample preparation

1. Obtain gastric cancer tissues (P0 = passage 0) directly from the operation. The tumor specimen should be larger than 0.5 cm³.
2. Prepare 3-4 mL of s....

Results

Here, tumor tissues from an operation were preserved in stock solution until the next step. Within 4 hours, tumor tissues were cut into small pieces and implanted into the dorsal flanks of NSG mice that had been anesthetized using isoflurane-soaked cotton. Tumors larger than 1 cm³ could be resected for implantation into new mice (Figure 1) or sliced carefully and preserved in liquid nitrogen following the protocol. In this study, the first-generation tumors grew more slowly than t.......

Discussion

Gastric cancer is an aggressive disease with limited therapeutic options; thus, models of gastric cancer have become a critical resource to enable functional research studies with direct translation to the clinic^4,8,17. Here, we have described the methods and protocol of establishing gastric cancer PDX models and primary cell lines. Importantly, both morphological and biological characteristics of gastric cancer specimens were m.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
40 μm Cell Strainer	Biologix, Shandong, China	15-1040
Biological Microscope	OLYMPUS, Tokyo, Japan	OLYMPUS CKX41
Centrifuge	Eppendorf, Mittelsachsen, Germany.	5427R
CO2 Incubator	Thermo Fisher Scientific, Carlsbad, California, USA	HERACELL 150i
DPBS	Basalmedia Technology, Shanghai, China	L40601
Electro-Thermostatic Water Cabinet	Yiheng, Shanghai, China	DK-8AXX
Fetal bovine serum	Wisent Biotechnology, Vancouver, Canada	86150040
Isoflurane	Baxter, China	CN2L9100
Live Tissue Kit Cryo Kit	Celliver Biotechnology, Shanghai, China	LT2601
Live Tissue Thaw Kit	Celliver Biotechnology, Shanghai, China	LT2602
NSG	Biocytogen, Beijing, China	B-CM-002-4-5W
Penicilin&streptomycin	Thermo Fisher Scientific, Carlsbad, California, USA	15140122
Red blood cell lysis buffer	Solarbio, Beijing, China	R1010
RPMI-1640 medium	Thermo Fisher Scientific, Carlsbad, California, USA	8118367
Surgical Suture Needles with Thread	LingQiao, Ningbo, China	3/8 arc 4×10
Tissue-processed molds and auxiliary blades	Celliver Biotechnology, Shanghai, China	LT2603
Trypsin-EDTA	Thermo Fisher Scientific, Carlsbad, California, USA	2003779
Type 1 collagenase	Thermo Fisher Scientific, Carlsbad, California, USA	17100017