title: In Vitro Tumor Models: Advantages, Disadvantages, Variables, and Selecting the Right Platform.
abstract: In vitro tumor models have provided important tools for cancer research and serve as low-cost screening platforms for drug therapies; however, cancer recurrence remains largely unchecked due to metastasis, which is the cause of the majority of cancer-related deaths. The need for an improved understanding of the progression and treatment of cancer has pushed for increased accuracy and physiological relevance of in vitro tumor models. As a result, in vitro tumor models have concurrently increased in complexity and their output parameters further diversified, since these models have progressed beyond simple proliferation, invasion, and cytotoxicity screens and have begun recapitulating critical steps in the metastatic cascade, such as intravasation, extravasation, angiogenesis, matrix remodeling, and tumor cell dormancy. Advances in tumor cell biology, 3D cell culture, tissue engineering, biomaterials, microfabrication, and microfluidics have enabled rapid development of new in vitro tumor models that often incorporate multiple cell types, extracellular matrix materials, and spatial and temporal introduction of soluble factors. Other innovations include the incorporation of perfusable microvessels to simulate the tumor vasculature and model intravasation and extravasation. The drive toward precision medicine has increased interest in adapting in vitro tumor models for patient-specific therapies, clinical management, and assessment of metastatic potential. Here, we review the wide range of current in vitro tumor models and summarize their advantages, disadvantages, and suitability in modeling specific aspects of the metastatic cascade and drug treatment.
authors.affiliation: Institute for Nanobiotechnology (INBT), Johns Hopkins University, Baltimore, MD, USA; Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Moriah E
authors.initials: ME
authors.lastname: Katt
authors.affiliation: Institute for Nanobiotechnology (INBT), Johns Hopkins University, Baltimore, MD, USA; Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Amanda L
authors.initials: AL
authors.lastname: Placone
authors.affiliation: Institute for Nanobiotechnology (INBT), Johns Hopkins University, Baltimore, MD, USA; Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Wong
authors.affiliation: Institute for Nanobiotechnology (INBT), Johns Hopkins University, Baltimore, MD, USA; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Zinnia S
authors.initials: ZS
authors.lastname: Xu
authors.affiliation: Institute for Nanobiotechnology (INBT), Johns Hopkins University, Baltimore, MD, USA; Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD, USA; Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Searson
keywords: metastasis; microvessel models; spheroids; transwell assay; tumor models