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Updated: Sep 5, 2025
08:40
Genome-wide Screen for miRNA Targets Using the MISSION Target ID Library
Published on: April 6, 2012
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MicroRNA-21 is immunosuppressive and pro-metastatic via separate mechanisms
Lap Hing Chi1, Ryan S N Cross2, Richard P Redvers1
1Olivia Newton-John Cancer Research Institute, HeidelbergVIC, Australia.
Oncogenesis
|July 12, 2022
Summary
Suppression of microRNA-21 (miR-21) activity halted primary mammary tumor growth in immunocompetent mice by enhancing anti-tumor immunity. miR-21 also promotes cancer metastasis, suggesting miR-21 targeted therapies could combat tumor progression.
Area of Science:
- Oncology
- Immunology
- Molecular Biology
Background:
- MicroRNA-21 (miR-21) is linked to poor cancer prognosis and metastasis.
- Its role in spontaneous mammary tumor growth and metastasis requires further investigation.
Purpose of the Study:
- To investigate the role of miR-21 in mammary tumor growth and metastasis.
- To explore the potential of targeting miR-21 for cancer therapy.
Main Methods:
- Studied miR-21 suppression in murine mammary tumors in immunocompetent and immunocompromised mice.
- Analyzed immune cell infiltrates (CD4+, CD8+, PD-L1+), tumor transcriptomics, and proteomics.
- Assessed tumor growth, metastasis, and immune suppression.
Main Results:
- miR-21 suppression caused primary tumor regression in immunocompetent mice via T-cell influx and reduced PD-L1+ monocytes.
- Transcriptomic analysis revealed reduced cell cycle gene expression.
- miR-21 knockdown impaired metastasis in immunocompromised mice.
- Proteomic analysis showed deregulation of tumor progression proteins.
Conclusions:
- miR-21 drives mammary tumor growth by suppressing anti-tumor immunity and promotes metastasis.
- Targeting miR-21 may offer a therapeutic strategy against primary tumor growth and metastasis.
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