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Regulatory Effect of let-7f Transfection in Non-Small Cell Lung Cancer on its Candidate Target Genes
Venus Zafari1,2, Milad Asadi, Nasim Bakhtiyari3,2
1Tuberculosis and Lung Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
Background:
Let-7f has essential impacts on biological processes; however, its biological and molecular functions in lung cancer pathogenesis have yet been remained unclear. We aimed to investigate the expression level of let-7f and its candidate target genes both in lung cancer tissues and A549 cell line.
Methods:
Bioinformatics databases were first used to select candidate target genes of let-7f. Then the relative gene and protein expressions of let-7f and its target genes, including HMGA2, ARID3B, SMARCAD1, and FZD3, were measured in lung tissues of NSCLC patients and A549 cell line using qRT-PCR and Western blotting. The electroporation method was used to transfect A549 cells with let-7f mimic and microRNA inhibitor. The impact of let-7f transfection on the viability of A549 cells was assessed using MTT assay. The expression data of studied genes were analyzed statistically.
Results:
Results indicated significant downregulated expression level of let-7f-5p (p = 0.0013) and upregulated level of the HMGA2 and FZD3 in NSCLC cases (p < 0.05). In A549 cells, after transfection with let-7f mimic, the expression of both mRNA and protein levels of HMGA2, ARID3B, SMARCAD1, and FZD3 decreased. Also, the overexpression of let-7f significantly inhibited the A549 cell proliferation and viability (p = 0.017).
Conclusion:
Our findings exhibited the high value of let-7f and HMGA2 as biomarkers for NSCLC. The let-7f, as a major tumor suppressor regulatory factor via direct targeting genes (e.g. HMGA2), inhibits lung cancer cell viability and proliferation and could serve as a marker for the early diagnostic of NSCLC.
Insights
Let-7f microRNA is downregulated in non-small cell lung cancer (NSCLC). Overexpressing let-7f inhibits lung cancer cell proliferation and viability, suggesting its potential as a diagnostic biomarker.
Area of Science:
- Molecular Biology
- Oncology
- Biochemistry
Background:
- Let-7f microRNA's role in biological processes is established, but its specific functions in lung cancer pathogenesis remain unclear.
- Investigating let-7f expression and its target genes in lung cancer is crucial for understanding disease mechanisms.
Purpose of the Study:
- To determine the expression levels of let-7f and its candidate target genes in lung cancer tissues and cell lines.
- To elucidate the molecular mechanisms underlying let-7f's function in lung cancer.
Main Methods:
- Bioinformatics analysis to identify let-7f target genes.
- Quantitative real-time PCR (qRT-PCR) and Western blotting to measure gene and protein expression in NSCLC tissues and A549 cells.
- Transfection of A549 cells with let-7f mimic and inhibitor, followed by MTT assay to assess cell viability.
Main Results:
- Let-7f-5p was significantly downregulated, while HMGA2 and FZD3 were upregulated in NSCLC tissues.
- Overexpression of let-7f in A549 cells led to decreased expression of HMGA2, ARID3B, SMARCAD1, and FZD3 at both mRNA and protein levels.
- Let-7f overexpression significantly inhibited A549 cell proliferation and viability.
Conclusions:
- Let-7f acts as a tumor suppressor in lung cancer by directly targeting genes like HMGA2.
- Let-7f and HMGA2 show potential as valuable biomarkers for NSCLC diagnosis and prognosis.
- Targeting let-7f could be a therapeutic strategy for NSCLC.
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