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Updated: Aug 9, 2026
Isolation, Enrichment, and Maintenance of Medulloblastoma Stem Cells
Published on: September 1, 2010
Shh pathway activity is down-regulated in cultured medulloblastoma cells: implications for preclinical studies
Ken Sasai1, Justyna T Romer, Youngsoo Lee
1Department of Developmental Neurobiology, Saint Jude Children's Research Hospital, Memphis, Tennessee 38105, USA.
Abstract:
Gene expression profiling indicates that the Sonic Hedgehog (Shh) pathway is active in approximately 30% of human medulloblastomas, suggesting that it could provide a useful therapeutic target. Previously, we showed that spontaneous medulloblastomas in Ptc1(+/-)p53-/- mice could be eradicated by treatment with a small-molecule inhibitor (HhAntag) of Smoothened (Smo). Here, we compared the responses of mouse medulloblastoma cells propagated in flank allografts, either directly or after culture in vitro, to HhAntag. We found that Shh pathway activity was suppressed in medulloblastoma cells cultured in vitro and it was not restored when these cells were transplanted into the flank of nude mice. The growth of these transplanted tumor cells was not inhibited by treatment of mice with doses of HhAntag that completely suppressed Smo activity. Interestingly, tumor cells transplanted directly into the flank maintained Smo activity and were sensitive to treatment with HhAntag. These findings indicate that propagation of tumor cells in culture inhibits Smo activity in a way that cannot be reversed by transplantation in vivo, and they raise concerns about the use of cultured tumor cells to test the efficacy of Shh pathway inhibitors as anticancer therapies.
Insights
Medulloblastoma cells cultured in vitro lose Sonic Hedgehog pathway activity, hindering their response to Smoothened inhibitors. Tumor cells transplanted directly retain pathway activity and sensitivity to Shh pathway targeted therapy.
Area of Science:
- Oncology
- Molecular Biology
- Cancer Research
Background:
- The Sonic Hedgehog (Shh) pathway is implicated in approximately 30% of human medulloblastomas.
- Shh pathway inhibitors targeting Smoothened (Smo) have shown promise in preclinical models.
Purpose of the Study:
- To compare the response of medulloblastoma cells to Shh pathway inhibition after in vitro culture versus direct transplantation.
- To assess the impact of cell culture on Smo activity and drug sensitivity.
Main Methods:
- Comparison of mouse medulloblastoma cells propagated in vitro versus directly in flank allografts.
- Treatment with a small-molecule Smo inhibitor (HhAntag).
- Assessment of Shh pathway activity and tumor growth inhibition.
Main Results:
- In vitro cultured medulloblastoma cells exhibited suppressed Shh pathway activity and Smo function.
- Transplantation of cultured cells into nude mice did not restore Shh pathway activity or drug sensitivity.
- Medulloblastoma cells transplanted directly into flank allografts maintained Smo activity and responded to HhAntag treatment.
Conclusions:
- Propagation of medulloblastoma cells in vitro leads to an irreversible loss of Smo activity.
- Cultured tumor cells are not suitable for testing the efficacy of Shh pathway inhibitors.
- These findings highlight the importance of using appropriate models for evaluating targeted cancer therapies.
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