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Published on: April 6, 2012
[microRNA let-7g-3p regulates proliferation, migration, invasion and apoptosis of bladder cancer cells by targeting
1Department of Urology, First Affiliated Hospital of Bengbu Medical College, Bengbu 233004, China.
Objective:
To explore the molecular mechanism by which microRNA let-7g-3p regulates biological behaviors of bladder cancer cells.
Methods:
The expression levels of let-7g-3p in bladder cancer and adjacent tissues, normal bladder epithelial cells (HUC cells) and bladder cancer cells (T24, 5637 and EJ cells) were detected using qRT- PCR. T24 cells were transfected with let-7g-3p mimic or inhibitor, and the changes in cell proliferation, migration, invasion, and apoptosis were examined. Transcriptome sequencing was carried out in cells overexpressing let-7g-3p, and the results of bioinformatics analysis, double luciferase reporter gene assay, qRT-PCR and Western blotting confirmed that HMGB2 gene was the target gene of let-7g-3p. The expression of HMGB2 was examined in HUC, T24, 5637 and EJ cells, and in cells with HMGB2 knockdown, the effect of let-7g-3p knockdown on the biological behaviors were observed.
Results:
qRT-qPCR confirmed that let-7g-3p expression was significantly lower in bladder cancer tissues and cells (P < 0.01). Overexpression of let-7g-3p inhibited cell proliferation, migration and invasion, and promoted cell apoptosis, while let-7g-3p knock-down produced the opposite effects. Bioinformatics and transcriptome sequencing results showed that HMGB2 was the key molecule that mediate the effect of let-7g-3p on bladder cancer cells. Luciferase reporter gene assay, qRT-PCR and Western blotting all confirmed that HMGB2 was negatively regulated by let-7g-3p (P < 0.01). Knocking down HMGB2 could partially reverse the effect of let-7g-3p knockdown on the biological behaviors of the bladder cancer cells.
Conclusion:
The microRNA let-7g-3p can inhibit the biological behavior of bladder cancer cells by negatively regulating HMGB2 gene.
Insights
MicroRNA let-7g-3p, found at lower levels in bladder cancer, inhibits tumor cell proliferation, migration, and invasion. It achieves this by downregulating the HMGB2 gene, offering a potential therapeutic target for bladder cancer.
Area of Science:
- Molecular Biology
- Oncology
- Biochemistry
Background:
- Bladder cancer is a significant health concern with complex molecular underpinnings.
- MicroRNAs (miRNAs) play crucial roles in regulating gene expression and are implicated in various cancers.
- Understanding the specific roles of miRNAs like let-7g-3p in bladder cancer is essential for developing targeted therapies.
Purpose of the Study:
- To elucidate the molecular mechanism by which microRNA let-7g-3p influences the biological behaviors of bladder cancer cells.
- To identify the target gene(s) regulated by let-7g-3p in the context of bladder cancer.
- To investigate the therapeutic potential of targeting the let-7g-3p/HMGB2 axis in bladder cancer.
Main Methods:
- Quantitative real-time PCR (qRT-PCR) was used to assess let-7g-3p and HMGB2 expression in bladder cancer tissues and cell lines.
- Functional assays (proliferation, migration, invasion, apoptosis) were performed on bladder cancer cells transfected with let-7g-3p mimics or inhibitors.
- Transcriptome sequencing, bioinformatics analysis, dual-luciferase reporter assays, and Western blotting were employed to identify and validate HMGB2 as a direct target of let-7g-3p.
Main Results:
- let-7g-3p expression was significantly downregulated in bladder cancer tissues and cells compared to normal controls.
- Overexpression of let-7g-3p suppressed bladder cancer cell proliferation, migration, and invasion, while promoting apoptosis.
- HMGB2 was confirmed as a direct target gene negatively regulated by let-7g-3p, and its knockdown partially reversed the effects of let-7g-3p inhibition.
Conclusions:
- The microRNA let-7g-3p acts as a tumor suppressor in bladder cancer.
- let-7g-3p inhibits bladder cancer cell biological behaviors, including proliferation, migration, and invasion, by negatively regulating the HMGB2 gene.
- Targeting the let-7g-3p/HMGB2 pathway represents a promising therapeutic strategy for bladder cancer.
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