A molecular screening approach to identify and characterize inhibitors of glioblastoma stem cells
Koppany Visnyei1, Hideyuki Onodera, Robert Damoiseaux
1Intellectual and Developmental Disabilities Research Center, Department of Psychiatry, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA.
Abstract:
Glioblastoma (GBM) is among the most lethal of all cancers. GBM consist of a heterogeneous population of tumor cells among which a tumor-initiating and treatment-resistant subpopulation, here termed GBM stem cells, have been identified as primary therapeutic targets. Here, we describe a high-throughput small molecule screening approach that enables the identification and characterization of chemical compounds that are effective against GBM stem cells. The paradigm uses a tissue culture model to enrich for GBM stem cells derived from human GBM resections and combines a phenotype-based screen with gene target-specific screens for compound identification. We used 31,624 small molecules from 7 chemical libraries that we characterized and ranked based on their effect on a panel of GBM stem cell-enriched cultures and their effect on the expression of a module of genes whose expression negatively correlates with clinical outcome: MELK, ASPM, TOP2A, and FOXM1b. Of the 11 compounds meeting criteria for exerting differential effects across cell types used, 4 compounds showed selectivity by inhibiting multiple GBM stem cells-enriched cultures compared with nonenriched cultures: emetine, n-arachidonoyl dopamine, n-oleoyldopamine (OLDA), and n-palmitoyl dopamine. ChemBridge compounds #5560509 and #5256360 inhibited the expression of the 4 mitotic module genes. OLDA, emetine, and compounds #5560509 and #5256360 were chosen for more detailed study and inhibited GBM stem cells in self-renewal assays in vitro and in a xenograft model in vivo. These studies show that our screening strategy provides potential candidates and a blueprint for lead compound identification in larger scale screens or screens involving other cancer types.
Insights
Researchers identified effective compounds against glioblastoma (GBM) stem cells using a high-throughput screening approach. This method targets treatment-resistant GBM stem cells, offering new therapeutic strategies for this lethal cancer.
Area of Science:
- Oncology
- Molecular Biology
- Drug Discovery
Background:
- Glioblastoma (GBM) is a highly lethal cancer characterized by a heterogeneous cell population.
- A subpopulation of GBM cells, known as GBM stem cells, are responsible for tumor initiation and treatment resistance.
- Identifying effective therapeutic targets against GBM stem cells is crucial for improving patient outcomes.
Purpose of the Study:
- To develop and implement a high-throughput small molecule screening approach for identifying compounds effective against GBM stem cells.
- To characterize and rank chemical compounds based on their effects on GBM stem cell-enriched cultures and specific gene expression.
- To identify novel lead compounds for GBM stem cell-targeted therapies.
Main Methods:
- Utilized a tissue culture model to enrich for GBM stem cells from human GBM resections.
- Performed a phenotype-based screen combined with gene target-specific screens for compound identification.
- Screened 31,624 small molecules from 7 chemical libraries, assessing effects on GBM stem cell cultures and expression of key genes (MELK, ASPM, TOP2A, FOXM1b).
Main Results:
- Identified 11 compounds with differential effects across cell types; 4 compounds (emetine, n-arachidonoyl dopamine, n-oleoyldopamine (OLDA), n-palmitoyl dopamine) selectively inhibited GBM stem cell-enriched cultures.
- Two ChemBridge compounds (#5560509 and #5256360) inhibited the expression of the four targeted mitotic module genes.
- OLDA, emetine, and compounds #5560509 and #5256360 demonstrated efficacy in inhibiting GBM stem cells in vitro self-renewal assays and in vivo xenograft models.
Conclusions:
- The developed high-throughput screening strategy is effective for identifying potential therapeutic candidates against GBM stem cells.
- The identified compounds, including OLDA and emetine, show promise as lead compounds for further drug development.
- This screening paradigm provides a blueprint for future large-scale screens and applications in other cancer types.
