Dataset Information

MiR-200c downregulates HIF-1? and inhibits migration of lung cancer cells.

ABSTRACT:

Background

Hypoxia-inducible factor-1? (HIF-1?) is a transcription factor with a pivotal role in physiological and pathological responses to hypoxia. While HIF-1? is known to be involved in hypoxia-induced upregulation of microRNA (miRNA) expression, HIF-1? is also targeted by miRNAs. In this study, miRNAs targeting HIF-1? were identified and their effects on its expression and downstream target genes under hypoxic conditions were investigated. Cell migration under the same conditions was also assessed.

Methods

microRNAs that target HIF-1? were screened using 3'-untranslated region luciferase (3'-UTR-luciferase) reporter assays. The expression levels of HIF-1? and its downstream target genes after transfection with miRNA were assessed using quantitative RT-PCR and western blot analyses. The effect of the miRNAs on the transcriptional activity of HIF-1? was determined using hypoxia-responsive element luciferase (HRE-luciferase) assays. Cell migration under hypoxia was examined using the wound-healing assay.

Results

Several of the 19 screened miRNAs considerably decreased the luciferase activity. Transfection with miR-200c had substantial impact on the expression level and transcription activity of HIF-1?. The mRNA level of HIF-1? downstream genes decreased in response to miR-200c overexpression. MiR-200c inhibited cell migration in normoxia and, to a greater extent, in hypoxia. These effects were partly reversed by HIF-1? expression under hypoxic conditions.

Conclusion

miR-200c negatively affects hypoxia-induced responses by downregulating HIF-1?, a key regulator of hypoxia. Therefore, overexpression of miR-200c might have therapeutic potential as an anticancer agent that inhibits tumor hypoxia.

SUBMITTER: Byun Y

PROVIDER: S-EPMC6487019 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

MiR-200c downregulates HIF-1α and inhibits migration of lung cancer cells.

Byun Yuree Y Choi Young-Chul YC Jeong Yunhui Y Lee Gangtae G Yoon Sena S Jeong Yongsu Y Yoon Jaeseung J Baek Kwanghee K

Cellular & molecular biology letters 20190427

<h4>Background</h4>Hypoxia-inducible factor-1α (HIF-1α) is a transcription factor with a pivotal role in physiological and pathological responses to hypoxia. While HIF-1α is known to be involved in hypoxia-induced upregulation of microRNA (miRNA) expression, HIF-1α is also targeted by miRNAs. In this study, miRNAs targeting HIF-1α were identified and their effects on its expression and downstream target genes under hypoxic conditions were investigated. Cell migration under the same conditions wa ...[more]

PMID: 31061665

Similar Datasets

Project description:BackgroundThe involvement of miRNAs in the regulation of fundamental cellular functions has placed them at the fore of ongoing investigations into the processes underlying carcinogenesis. MiRNA expression patterns have been shown to be dysregulated in numerous human malignancies, including breast cancer, suggesting their probable involvement as novel classes of oncogenes or tumour suppressor genes. The identification of differentially expressed miRNAs and elucidation of their functional roles may provide insight into the complex and diverse molecular mechanisms of tumorigenesis. MiR-183 is located on chromosome 7q32 and is part of a miRNA family which are dysregulated in numerous cancers. The aims of this study were to further examine the expression and functional role of miR-183 in breast cancer.MethodsMiR-183 expression was quantitated in primary breast tumours, tumour associated normal tissue and breast cancer cell lines using RQ-PCR. Gain of function analysis was performed in breast cancer cells using pre-miR-183 and the effect of miR-183 overexpression on cell viability, proliferation, apoptosis and migration was examined. Customized Taqman Low Density Arrays (TLDA) were used to identify dysregulated genes in breast cancer cells transfected with pre-miR-183.ResultsWe demonstrate that miR-183 is dysregulated in breast cancer and expression correlates with estrogen receptor and HER2/neu receptor expression. Induced overexpression of miR-183 inhibited migration of breast cancer cells. This finding was substantiated by RQ-PCR of mRNA from cells overexpressing miR-183 which showed dysregulation of several migration and invasion related genes. Specifically, the VIL2-coding protein Ezrin was confirmed as a target of miR-183 and downregulation of this protein was confirmed with immunocytochemistry.ConclusionsThese findings indicate that miR-183 targets VIL2 and may play a central role in the regulation of migration and metastasis in breast cancer. Consequently, this miRNA may present an attractive target for therapeutic intervention.