Cited by 4043D Printing in Biomedical ResearchCancer Cells and MetastasisHydrogels: synthesis, properties, applications

The production of 3D tumor spheroids for cancer drug discovery

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Sant, Shilpa, Johnston, Paul A.·2017·Drug Discovery Today: Technologies

Abstract

New cancer drug approval rates are ≤ 5% despite significant investments in cancer research, drug discovery and development. One strategy to improve the rate of success of new cancer drugs transitioning into the clinic would be to more closely align the cellular models used in the early lead discovery with pre-clinical animal models and patient tumors. For solid tumors, this would mandate the development and implementation of three dimensional (3D) in vitro tumor models that more accurately recapitulate human solid tumor architecture and biology. Recent advances in tissue engineering and regenerative medicine have provided new techniques for 3D spheroid generation and a variety of in vitro 3D cancer models are being explored for cancer drug discovery. Although homogeneous assay methods and high content imaging approaches to assess tumor spheroid morphology, growth and viability have been developed, the implementation of 3D models in HTS remains challenging due to reasons that we discuss in this review. Perhaps the biggest obstacle to achieve acceptable HTS assay performance metrics occurs in 3D tumor models that produce spheroids with highly variable morphologies and/or sizes. We highlight two methods that produce uniform size-controlled 3D multicellular tumor spheroids that are compatible with cancer drug research and HTS; tumor spheroids formed in ultra-low attachment microplates, or in polyethylene glycol dimethacrylate hydrogel microwell arrays.

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Crossref · 10.1016/j.ddtec.2017.03.002

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  • When a tumor exceeds a critical diameter of 200 μm, hypoxia develops at its central core.

    “When a tumor exceeds a critical diameter of 200 μm, hypoxia develops at its central core, and a complex biochemical cascade commands vascularization to start [126,184].”

    From The Tumor-on-Chip: Recent Advances in the Development of Microfluidic Systems to Recapitulate the Physiology of Solid Tumors (2019) · cites this paper as [126]

    The PEGDMA hydrogel microwell arrays section reports a hypoxic central core in large (600 μm) breast-cancer microtumors. It does not establish 200 μm as a critical diameter for tumors generally. The section also reports increased pro-angiogenic VEGF, but not that vascularization begins. (LLM, conf=0.88)

    Experimental — accuracy not yet measured
  • A complex biochemical cascade commands vascularization to start when a tumor exceeds a critical diameter of 200 μm.

    “When a tumor exceeds a critical diameter of 200 μm, hypoxia develops at its central core, and a complex biochemical cascade commands vascularization to start [126,184].”

    From The Tumor-on-Chip: Recent Advances in the Development of Microfluidic Systems to Recapitulate the Physiology of Solid Tumors (2019) · cites this paper as [126]

    The PEGDMA hydrogel microwell arrays section reports a hypoxic central core and increased pro-angiogenic VEGF in 600 μm breast-cancer microtumors. It does not establish a critical diameter of 200 μm or show that a biochemical cascade initiates vascularization at that threshold; the reported finding concerns an angiogenic signal, not observed vessel formation. No page number is available in our copy. (LLM, conf=0.88)

    Experimental — accuracy not yet measured
  • Suspension culture generally has high throughput but lacks the ability to control the size and uniformity of the spheroids formed.

    “Suspension culture generally has high throughput but lack the ability to control the size and uniformity of the spheroids formed [64,65].”

    From Microfluidic modelling of the tumor microenvironment for anti-cancer drug development (2019) · cites this paper as [65]

    The ‘Anchorage-independent tumor spheroids’ section says many methods produce aggregates with widely varying sizes and morphologies, supporting the uniformity concern. It does not support the claim that suspension culture generally has high throughput: it says some methods are labor-intensive and have been used only for small pilot screens. The ‘Ultra-low attachment microplates’ section also describes a method that is suitable for high-throughput screening and produces uniform-sized spheroids. (LLM, conf=0.88)

    Experimental — accuracy not yet measured
  • Tumor spheroids can be used to mimic in vivo tumor microenvironments because they have the ability to provide metabolism, proliferation, and species concentration gradients similar to those found in vivo.

    “It can be used to mimic in vivo tumor microenvironments because it has the ability to provide metabolism, proliferation, and species concentration gradients similar to those found in vivo175,176.”

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Authors
Sant, S., & Johnston, P. A.
Affiliations
University of Pittsburgh (US)
Corresponding author
Johnston, Paul A.
Venue
Drug Discovery Today: Technologies
Publisher
Elsevier BV
Published
2017-03
Volume
23
Pages
27-36
ISSN
1740-6749 (ISSN-L)
OpenAlex
W2606980922
Cited by
404
References
51
Citations by year
2026: 29 · 2025: 38 · 2024: 45 · 2023: 53 · 2022: 52 · 2021: 55 · 2020: 64 · 2019: 37 · 2018: 25 · 2017: 6
FWCI
2.90
Type
journal article
Language
en
Open access
Locations
  • Drug Discovery Today Technologies (publishedVersion)
  • PubMed (publishedVersion)
  • Europe PMC (PubMed Central) (acceptedVersion)
  • PubMed Central (acceptedVersion)
Funders
  • NIH (EB018575)
  • Department of Pharmaceutical Sciences at University of Pittsburgh
Topics
  • Physical Sciences › Engineering › Biomedical Engineering › 3D Printing in Biomedical Research
  • Health Sciences › Medicine › Oncology › Cancer Cells and Metastasis
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Medicine › Hydrogels: synthesis, properties, applications
Keywords
tumor spheroids, anticancer drug discovery, high-throughput screening, 3D tumor models, spheroid morphology, tissue engineering
MeSH terms
Animals, Antineoplastic Agents, Humans, Methacrylates, Polyethylene Glycols, Tumor Cells, Cultured, Spheroids, Cellular, Hydrogels, Drug Discovery, High-Throughput Screening Assays, Tumor Microenvironment

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