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Analysis of Combinatorial miRNA Treatments to Regulate Cell Cycle and Angiogenesis
Published on: March 30, 2019
MicroRNA-326 impairs chemotherapy resistance in non small cell lung cancer by suppressing histone deacetylase
Jinying Wei1,2, Guangping Meng1, Jing Wu2
1Department of Respiratory and Critical Care Medicine, The Second Hospital of Jilin University, Changchun, P. R. China.
Abstract:
Compelling evidence has implicated the role of microRNAs (miRs or miRNAs) in lung cancer. Sirtuin-1 (SIRT1) is a key contributor to the progression of non-small cell lung cancer (NSCLC). This study was intended to investigate whether miR-326 affected NSCLC associated with SIRT1. miR-326 and SIRT1 expression in H460 cells and chemoresistant cells H460-R was measured by RT-qPCR. Dual luciferase reporter gene assay and RIP assay were used to identify and validate the relationship between miR-326 and SIRT1. Using gain- and loss-of-function approaches, we evaluated their effects on the chemoresistance of NSCLC cells. ChIP assay was used to detect binding of SIRT1 to the promoter of HIF1α gene, and the binding H3K9Ac to HIF1α, binding of H3K9Ac and HIF1α after silencing SIRT1, and binding HIF1α to VEGFA promoter. In vivo experiments were performed to validate the in vitro findings. MiR-326 expression was decreased while SIRT1 expression was increased in NSCLC cells. SIRT1 was a target of miR-326. MiR-326 inhibited the proliferation of chemotherapy-resistant NSCLC cells and promoted their apoptosis by suppressing SIRT1. In addition, SIRT1 promoted chemoresistance of NSCLC cell by elevating VEGFA expression. Through this mechanism, miR-326 reduced the chemoresistance, which was validated in vivo. Taken together, miR-326 represses SIRT1 through impeding HIF1α expression, thus hindering chemotherapy resistance in lung cancer. These findings provide an exquisite therapeutic target for NSCLC.
Insights
MicroRNA-326 (miR-326) combats non-small cell lung cancer (NSCLC) chemoresistance by targeting Sirtuin-1 (SIRT1). This interaction inhibits cancer cell proliferation and enhances apoptosis, offering a new therapeutic strategy for lung cancer.
Area of Science:
- Molecular Biology
- Oncology
- Biochemistry
Background:
- MicroRNAs (miRNAs) play a significant role in lung cancer development.
- Sirtuin-1 (SIRT1) is identified as a critical factor in the progression of non-small cell lung cancer (NSCLC).
Purpose of the Study:
- To investigate the regulatory role of miR-326 in NSCLC, specifically its association with SIRT1.
- To elucidate the mechanism by which miR-326 influences chemoresistance in NSCLC cells.
Main Methods:
- Quantitative real-time PCR (RT-qPCR) for miRNA and gene expression analysis.
- Dual luciferase reporter and RNA immunoprecipitation (RIP) assays to confirm miRNA-target interaction.
- Gain- and loss-of-function studies, Chromatin immunoprecipitation (ChIP) assays, and in vivo experiments.
Main Results:
- miR-326 expression was downregulated, while SIRT1 expression was upregulated in NSCLC cells.
- SIRT1 was validated as a direct target of miR-326.
- miR-326 suppressed NSCLC cell proliferation and induced apoptosis by inhibiting SIRT1, thereby reducing chemoresistance.
- SIRT1 promotes chemoresistance by upregulating VEGFA expression via HIF1α.
- miR-326 effectively reduced chemoresistance in vivo.
Conclusions:
- miR-326 acts as a tumor suppressor in NSCLC by targeting SIRT1 and inhibiting the HIF1α/VEGFA pathway.
- This regulatory axis offers a promising therapeutic target for overcoming chemotherapy resistance in lung cancer patients.
