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Analysis of Combinatorial miRNA Treatments to Regulate Cell Cycle and Angiogenesis
Published on: March 30, 2019
MiR-21 and let-7 cooperation in the regulation of lung cancer
Jinquan Bai1, Zhenzhou Shi1, Shuting Wang1
1Department of Radiology, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, China.
Background:
Lung cancer occurs and develops as a result of a complicated process involving numerous genes; therefore, single-gene regulation has a limited therapeutic effect. We discovered that miR-21 expression was high in lung cancer tissues and cells, whereas let-7 expression was low, and it is unclear whether their combined regulation would be superior to therapy involving single regulation. The goal of our research was to investigate this situation and the regulatory mechanism that exists between these genes.
Methods:
To regulate the levels of miR-21 and let-7 in these two types of lung cancer cells, we transfected miRNA mimics or inhibitors into A549 and H460 cells. Lung cancer cells were tested for proliferation, apoptosis, migration, and invasion. The results were verified using a Western blot and a qRT-PCR assay. Bioinformatics was used to investigate their potential regulatory pathways, and luciferase assays were used to confirm the binding sites.
Results:
The expression of miR-21 was increased and that of let-7 was decreased in lung cancer tissues and cells compared with paracancerous tissues and normal lung cells (p < 0.01). Tumor cells were inhibited by downregulation of miR-21 and upregulation of let-7, and cooperative regulation showed a better effect. Upregulation of miR-21 and downregulation of let-7 promoted tumor cells, and this tumor-promoting effect was amplified by cooperative regulation. MiR-21 regulated lung cancer cells directly via the Wnt/-catenin pathway, and let-7 exerted its effects via the PLAG1/GDH1 pathway. MiR-21 and let-7 cooperated to regulate lung cancer cells via the K-ras pathway.
Conclusions:
The effect of cooperative regulation of miR-21 and let-7 on lung cancer is greater than that of a single miRNA. MiR-21 and let-7 are important differentially expressed genes in lung cancer that are regulated by the K-ras pathway. As a result, for multigene lung cancer, the cooperative regulation of two miRNAs will provide a new target and direction for lung cancer treatment in the future.
Insights
Cooperative regulation of miR-21 and let-7 shows superior therapeutic effects in lung cancer compared to single miRNA therapy. This combined approach, targeting the K-ras pathway, offers a promising new direction for treating multigene lung cancers.
Area of Science:
- Molecular Biology
- Oncology
- Gene Regulation
Background:
- Lung cancer involves complex genetic alterations, limiting single-gene therapeutic efficacy.
- MicroRNA-21 (miR-21) is upregulated, while let-7 is downregulated in lung cancer tissues and cells.
- The combined regulatory effects of miR-21 and let-7 on lung cancer remain largely unexplored.
Purpose of the Study:
- To investigate the synergistic or antagonistic regulatory mechanisms of miR-21 and let-7 in lung cancer.
- To explore the therapeutic potential of combined miR-21 and let-7 modulation in lung cancer.
- To elucidate the molecular pathways involved in the cooperative regulation of these miRNAs in lung cancer.
Main Methods:
- Transfection of miRNA mimics/inhibitors into A549 and H460 lung cancer cells.
- Assessment of cell proliferation, apoptosis, migration, and invasion.
- Validation using Western blot, qRT-PCR, bioinformatics, and luciferase assays.
Main Results:
- miR-21 expression was significantly higher, and let-7 expression was lower in lung cancer cells.
- Downregulation of miR-21 and upregulation of let-7 inhibited tumor cells, with cooperative regulation showing enhanced efficacy.
- miR-21 directly targets the Wnt/β-catenin pathway, let-7 targets the PLAG1/GDH1 pathway, and both cooperate via the K-ras pathway.
Conclusions:
- Cooperative regulation of miR-21 and let-7 yields superior therapeutic outcomes in lung cancer compared to single miRNA intervention.
- miR-21 and let-7 are key differentially expressed genes in lung cancer, regulated by the K-ras pathway.
- Combined modulation of miR-21 and let-7 presents a novel therapeutic strategy for multigene lung cancers.
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