Neurosphere Assays: Growth Factors and Hormone Differences in Tumor and Nontumor Studies

Authors

  • Kaisorn Chaichana,

    1. Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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  • Grettel Zamora-Berridi,

    1. Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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  • Joaquin Camara-Quintana,

    1. Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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  • Alfredo Quiñones-Hinojosa M.D.

    Corresponding author
    1. Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
    • The Johns Hopkins Hospital, Department of Neurosurgery, Johns Hopkins University, CRB II, 1550 Orleans Street, Room 253, Baltimore, Maryland 21231, USA. Telephone: 410-502-3204; Fax: 410-502-5559
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Abstract

The “no new neuron” dogma that the brain is quiescent throughout adult life has been challenged by the discovery of cells with stem cell-like qualities of self-renewal and multipotency in the subventricular zone of the lateral ventricles and the dentate gyrus of the hippocampus in adults. This self-renewing capacity also makes these neural stem cells a possible source of brain tumors, which was supported by the discovery of self-sustaining brain tumor stem-like cells in cancers such as glioblastoma multiforme. Neurosphere assays are the standard for studying these stem-like cells in both normal and cancer tissues. Despite the importance of these assays, there is no standardized protocol to allow for a comparison of results because several studies use different growth factors and hormones at different concentrations. The primary objective of this study is to review the literature for both nontumor and tumor studies to assess their respective neurosphere assay components. We found significant variation in assay components, namely hormones and growth factors, as well as their respective concentrations. This illustrates the need for a standardized protocol to allow proper comparison among studies and a better assessment of the effects of different factors.

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