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Updated: Feb 22, 2026
Characterization of Functionally Associated miRNAs in Glioblastoma and their Engineering into Artificial Clusters for Gene Therapy
Published on: October 4, 2019
MiR-320 inhibits the growth of glioma cells through downregulating PBX3
Cuicui Pan1, Hua Gao1, Ni Zheng1
1Department of Clinical Laboratory, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China.
Background:
MiR-320 is downregulated in multiple cancers, including glioma and acts as tumor suppressor through inhibiting tumor cells proliferation and inducing apoptosis. PBX3 (Pre-B cell leukemia homeobox 3), a putative target gene of miR-320, has been reported to be upregulated in various tumors and promote tumor cell growth through regulating MAKP/ERK pathway. This study aimed to verify whether miR-320 influences glioma cells growth through regulating PBX3.
Methods:
Twenty-four human glioma and paired adjacent nontumorous tissues were collected for determination of miR-320 and PBX3 expression using RT-qPCR and western blot assays. Luciferase reporter assay was performed to verify the interaction between miR-320 and its targeting sequence in the 3' UTR of PBX3 in glioma cells U87 and U251. Increased miR-320 level in U87 and U251 cells was achieved through miR-320 mimic transfection and the effect of which on glioma cells growth, proliferation, cell cycle, apoptosis and activation of Raf-1/MAPK pathway was determined using MTT, colony formation, flow cytometry and western blot assays. PBX3 knockdown was performed using shPBX3 and the influence on MAPK pathway activation was evaluated.
Results:
MiR-320 downregulation and PBX3 upregulation was found in glioma tissues. Luciferase reporter assays identified miR-320 directly blinds to the 3' UTR of PBX3 in glioma cells. MiR-320 mimic transfection suppressed glioma cells proliferation, and induced cell cycle arrest and apoptosis. Both miR-320 overexpression and PBX3 knockdown inhibited Raf-1/MAPK activation.
Conclusion:
MiR-320 may suppress glioma cells growth and induced apoptosis through the PBX3/Raf-1/MAPK axis, and miR-320 oligonucleotides may be a potential cancer therapeutic for glioma.
Insights
MicroRNA-320 (miR-320) suppresses glioma growth by targeting PBX3 (Pre-B cell leukemia homeobox 3) and inhibiting the Raf-1/MAPK pathway. This suggests miR-320 oligonucleotides could be a potential therapeutic for glioma.
Area of Science:
- Molecular Biology
- Oncology
- Gene Regulation
Background:
- MicroRNA-320 (miR-320) is downregulated in glioma, acting as a tumor suppressor by inhibiting proliferation and inducing apoptosis.
- Pre-B cell leukemia homeobox 3 (PBX3) is upregulated in tumors and promotes growth via the MAPK/ERK pathway, with miR-320 potentially targeting it.
Purpose of the Study:
- To investigate if miR-320 influences glioma cell growth by regulating PBX3.
- To elucidate the molecular mechanisms underlying miR-320's role in glioma.
Main Methods:
- Expression analysis of miR-320 and PBX3 in glioma tissues using RT-qPCR and Western blot.
- Luciferase reporter assays to confirm direct interaction between miR-320 and PBX3 3' UTR in glioma cells.
- Functional assays (MTT, colony formation, flow cytometry) to assess the impact of miR-320 mimic transfection and PBX3 knockdown on glioma cell behavior and MAPK pathway activation.
Main Results:
- Glioma tissues showed decreased miR-320 and increased PBX3 expression.
- miR-320 directly binds to the 3' UTR of PBX3 in glioma cells.
- miR-320 overexpression suppressed proliferation, induced cell cycle arrest, and apoptosis, while inhibiting Raf-1/MAPK activation. PBX3 knockdown also inhibited this pathway.
Conclusions:
- MiR-320 suppresses glioma growth and induces apoptosis via the PBX3/Raf-1/MAPK pathway.
- miR-320 oligonucleotides represent a potential therapeutic strategy for glioma treatment.
