title: Exploring Drug Dosing Regimens In Vitro Using Real-Time 3D Spheroid Tumor Growth Assays.
abstract: Two-dimensional monolayer cell proliferation assays for cancer drug discovery have made the implementation of large-scale screens feasible but only seem to reflect a simplified view that oncogenes or tumor suppressor genes are the genetic drivers of cancer cell proliferation. However, there is now increased evidence that the cellular and physiological context in which these oncogenic events occur play a key role in how they drive tumor growth in vivo and, therefore, in how tumors respond to drug treatments. In vitro 3D spheroid tumor models are being developed to better mimic the physiology of tumors in vivo, in an attempt to improve the predictability and efficiency of drug discovery for the treatment of cancer. Here we describe the establishment of a real-time 3D spheroid growth, 384-well screening assay. The cells used in this study constitutively expressed green fluorescent protein (GFP), which enabled the real-time monitoring of spheroid formation and the effect of chemotherapeutic agents on spheroid size at different time points of sphere growth and drug treatment. This real-time 3D spheroid assay platform represents a first step toward the replication in vitro of drug dosing regimens being investigated in vivo. We hope that further development of this assay platform will allow the investigation of drug dosing regimens, efficacy, and resistance before preclinical and clinical studies.
authors.affiliation: 1 National Center for Advancing Translations Sciences, Division of Preclinical Innovation, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Madhu
authors.initials: M
authors.lastname: Lal-Nag
authors.affiliation: 1 National Center for Advancing Translations Sciences, Division of Preclinical Innovation, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Lauren
authors.initials: L
authors.lastname: McGee
authors.affiliation: 1 National Center for Advancing Translations Sciences, Division of Preclinical Innovation, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Steven A
authors.initials: SA
authors.lastname: Titus
authors.affiliation: 1 National Center for Advancing Translations Sciences, Division of Preclinical Innovation, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Kyle
authors.initials: K
authors.lastname: Brimacombe
authors.affiliation: 1 National Center for Advancing Translations Sciences, Division of Preclinical Innovation, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Sam
authors.initials: S
authors.lastname: Michael
authors.affiliation: 1 National Center for Advancing Translations Sciences, Division of Preclinical Innovation, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Gurusingham
authors.initials: G
authors.lastname: Sittampalam
authors.affiliation: 1 National Center for Advancing Translations Sciences, Division of Preclinical Innovation, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Marc
authors.initials: M
authors.lastname: Ferrer
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D018929:Cell Culture Techniques / Q000379:methods; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D055808:Drug Discovery / Q000379:methods; D004354:Drug Screening Assays, Antitumor / Q000379:methods*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D018874:Spheroids, Cellular / Q000187:drug effects* / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D049452:Green Fluorescent Proteins
keywords: 3D; high throughput; phenotypic drug discovery; physiologically relevant