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In Vivo Inhibition of MicroRNA to Decrease Tumor Growth in Mice
Published on: August 23, 2019
A TARBP2 mutation in human cancer impairs microRNA processing and DICER1 function
Sonia A Melo1, Santiago Ropero, Catia Moutinho
1Cancer Epigenetics Laboratory, Spanish National Cancer Research Centre (CNIO), 28029 Madrid, Spain.
Nature Genetics
|February 17, 2009
Summary
Truncating mutations in TARBP2 impair microRNA (miRNA) processing, leading to reduced mature miRNA expression in certain cancers. Restoring TARBP2 function inhibits tumor growth, highlighting its role in cancer development.
Area of Science:
- Molecular Biology
- Genetics
- Oncology
Background:
- MicroRNAs (miRNAs) are key regulators of gene expression.
- Human tumors often exhibit global miRNA downregulation.
- Potential causes include transcriptional silencing and oncogenic repression, but defects in miRNA processing machinery were unconfirmed.
Purpose of the Study:
- To investigate genetic alterations in miRNA processing pathways in human cancers.
- To identify the molecular basis for miRNA downregulation in tumors with microsatellite instability.
Main Methods:
- Analysis of TARBP2 (TAR RNA-binding protein 2) in sporadic and hereditary carcinomas.
- Assessment of miRNA processing defects upon TARBP2 mutation.
- Functional studies involving reintroduction of TRBP in deficient cells.
- Investigation of DICER1 protein stability.
Main Results:
- Truncating mutations in TARBP2 were identified in carcinomas with microsatellite instability.
- TARBP2 mutations led to reduced TRBP protein expression and impaired miRNA processing.
- Reintroduction of TRBP restored miRNA production and inhibited tumor growth.
- TRBP deficiency destabilized DICER1 protein.
Conclusions:
- Genetic disruption of TARBP2 is a mechanism underlying miRNA processing defects in a subset of human tumors.
- TARBP2 mutations contribute to cellular transformation by affecting miRNA biogenesis.
- This finding provides a novel explanation for miRNA downregulation in specific cancer types.
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