Patient-Derived Xenografts of Non Small Cell Lung Cancer: Resurgence of an Old Model for Investigation of Modern Concepts of Tailored Therapy and Cancer Stem Cells

Table 1

Main advantages and disadvantages of GEM, XG, and PDX mouse models.

	Advantages	Disadvantages
Genetically engineered mice; (GEM)	(i) Studies on defined mutations; (ii) Possibility to follow tumor development from early time points; (iii) Tumor microenvironment is representative of the studied tumor; (iv) Potential analysis of effects of mutations in many genetic backgrounds by using a variety of mouse strains	(i) Limited number of genes (usually not representative of the heterogeneity of the tumor); (ii) Development costly and time consuming; (iii) Tumor development in animals slow and variable; (iv) Both, tumor and microenvironment are murine
Xenograft; (XG)	(i) Allows a rapid analysis of response to a therapeutic regimen; (ii) Source of material virtually unlimited for immortal cell lines; (iii) Can predict drug response of human patient’s tumor	(i) Human tumor microenvironment is not represented; (ii) Orthotopic implant is often technically complicated; (iii) Cells can undergo genetic modification as well as subpopulation rearrangements when cultured
Patient-derived xenograft; (PDX)	(i) Provides a realistic representation of the heterogeneity of tumor cell subpopulations; (ii) Can predict drug response of human patient’s tumor; (iii) Stromal component is representative of the parental tumor in the initial passages	(i) Orthotopic implant is often technically complicated; (ii) Surgical fragments must be processed rapidly; (iii) Limited source of original material