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Yeast As a Chassis for Developing Functional Assays to Study Human P53
Published on: August 4, 2019
p53 Regulates LIF expression in human medulloblastoma cells
1Department of Biology, Yorkshire Cancer Research p53 Research Unit, University of York, Heslington YO10 5DD, UK.
Journal of Neuro-Oncology
|November 13, 2009
Summary
The tumor suppressor protein p53 regulates LIF, crucial for maintaining stem cell pluripotency. Inhibiting WIP1 or SIRT1 reactivates p53, promoting apoptosis in medulloblastoma cells, suggesting SIRT1 inhibitors as a potential treatment.
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Background:
- Medulloblastomas are aggressive pediatric brain tumors, rarely mutating the TP53 gene.
- The TP53 protein (p53) is vital in cancer and also plays a role in reproduction by regulating uterine LIF expression.
- LIF (Leukemia Inhibitory Factor) is known to maintain stem cell pluripotency.
Purpose of the Study:
- To investigate whether p53 regulates LIF expression in human medulloblastoma cell lines.
- To determine the dependency of alternative LIF transcripts (LIF M and T) on p53.
- To explore the therapeutic potential of targeting WIP1 and SIRT1 in medulloblastoma.
Main Methods:
- Utilized human medulloblastoma cell lines (DAOY, D283MED) and isogenic HCT116 colorectal carcinoma cell lines (p53-/- and p53+/+).
- Performed chromatin immunoprecipitation to assess p53 binding to the LIF gene.
- Employed RNA interference (siRNA) against WIP1 and SIRT1.
Main Results:
- All three full-length LIF transcripts were more abundant in p53+/+ cells compared to p53-/- cells, with LIF M and T transcripts showing particular p53 sensitivity.
- p53 directly bound to the LIF gene in p53 wild-type D283MED cells, but not in DAOY cells expressing mutant p53.
- Inhibition of WIP1 or SIRT1 stabilized p53, enhanced LIF transcription, and induced apoptosis in medulloblastoma cell lines.
Conclusions:
- p53 regulates LIF expression, including alternative transcripts, in medulloblastoma cells.
- Suppression of p53 by WIP1 and SIRT1 may contribute to medulloblastoma cell survival.
- Targeting SIRT1 with small molecule inhibitors could be a viable therapeutic strategy for medulloblastoma treatment.
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