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Updated: Jun 2, 2026
Characterization of Functionally Associated miRNAs in Glioblastoma and their Engineering into Artificial Clusters for Gene Therapy
Published on: October 4, 2019
Analysis of miR-221 and p27 expression in human gliomas
Xiaoming Lu1, Peng Zhao, Chunzhi Zhang
1Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, P.R. China.
Abstract:
MicroRNAs (miRNAs) are short (≈22-nt) non-coding RNA molecules implicated in both development and disease that act by repressing translation or by inducing the cleavage of target RNA transcripts. Emerging evidence suggests that the altered regulation of miRNA may be involved in the pathogenesis of cancer. Here, we investigated the expression of the miRNA gene miR-221 by real-time PCR in human glioma tissues of varying grades of malignancy. The expression level of miR-221 was found to increase with glioma malignancy, whereas protein levels of a putative target, the cell cycle inhibitor and tumor suppressor gene p27Kip1, decreased. Using a luciferase reporter assay, we further confirmed the translational repression activity of miR-221 on p27 by identifying the target recognition element within the 3'UTR of p27. Our results suggest that miR-221 is a regulator of the tumor suppressor gene p27, and that its increased expression in advanced gliomas might contribute to glioma cell proliferation by a mechanism involving the repression of p27.
Insights
MicroRNAs (miRNAs) regulate gene expression and are linked to cancer. This study shows miR-221 increases with glioma grade, repressing the tumor suppressor p27 and potentially driving cancer cell growth.
Area of Science:
- Molecular Biology
- Oncology
- Genetics
Background:
- MicroRNAs (miRNAs) are key regulators of gene expression, implicated in development and disease.
- Aberrant miRNA regulation is increasingly recognized in cancer pathogenesis.
- Gliomas are primary brain tumors with varying malignancy grades.
Purpose of the Study:
- To investigate the expression of microRNA-221 (miR-221) in human gliomas.
- To determine the relationship between miR-221 expression and glioma malignancy.
- To elucidate the role of miR-221 in regulating the tumor suppressor gene p27Kip1.
Main Methods:
- Real-time PCR was used to quantify miR-221 expression in glioma tissues.
- Luciferase reporter assays were employed to confirm miR-221's translational repression activity on p27.
- Western blotting or similar techniques were used to assess p27Kip1 protein levels.
Main Results:
- miR-221 expression levels were significantly elevated in higher-grade gliomas.
- p27Kip1 protein levels showed an inverse correlation with miR-221 expression.
- The 3' untranslated region (3'UTR) of p27 was identified as the target recognition element for miR-221.
Conclusions:
- miR-221 acts as a regulator of the tumor suppressor gene p27.
- Increased miR-221 expression in advanced gliomas may promote proliferation via p27 repression.
- miR-221 represents a potential therapeutic target in glioma treatment.
