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An In Vitro Protocol for Evaluating MicroRNA Levels, Functions, and Associated Target Genes in Tumor Cells
Published on: May 21, 2019
miR-133b, a microRNA targeting S1PR1, suppresses nasopharyngeal carcinoma cell proliferation
1Department of Otolaryngology, Huaihe Hospital, Henan University, Kaifeng, Henan 475000, P.R. China.
Abstract:
MicroRNAs (miRs) are a class of short and non-coding RNA molecules, which function as either oncogenes or tumor suppressors in the development of various human cancers, including nasopharyngeal carcinoma (NPC). The aim of the present study was to investigate the expression of miR-133b in NPC tissue samples, as compared with adjacent normal tissues, and to examine its roles and underlying mechanisms. Analysis using reverse transcription-quantitative polymerase chain reaction demonstrated that miR-133b was downregulated in NPC tissue samples, as compared with adjacent tissues. In vitro experiments using NPC cell lines transfected with miR-133b mimics or antisense oligonucleotides further demonstrated that the overexpression of miR-133b mimics impaired, whereas knockdown of its expression promoted, the proliferation of NPC cells. Sphingosine-1-phosphate receptor 1 (S1PR1) was predicted to be a target of miR-133b. Luciferase reporter assays showed that miR-133b inhibited the protein expression of S1PR1 by targeting its 3'-untranslated region. Furthermore, western blot analysis demonstrated that miR-133B altered the regulation of the signal transducer and activator of transcription-3 (STAT3) signaling pathway and the expression of downstream proteins in NPC cells. Therefore, the results of the present study suggested that a previously unknown miR-133b/S1PR1 molecular network may regulate NPC progression.
Insights
MicroRNA-133b (miR-133b) is downregulated in nasopharyngeal carcinoma (NPC), suppressing tumor cell proliferation. It targets Sphingosine-1-phosphate receptor 1 (S1PR1), impacting the STAT3 pathway in NPC progression.
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Background:
- MicroRNAs (miRs) are key regulators in cancer, acting as oncogenes or tumor suppressors.
- Nasopharyngeal carcinoma (NPC) is a human cancer where miRs play a significant role.
- The specific role of miR-133b in NPC remains largely uncharacterized.
Purpose of the Study:
- To investigate the expression levels of miR-133b in NPC tissues versus adjacent normal tissues.
- To elucidate the functional role of miR-133b in NPC cell proliferation.
- To identify the molecular targets and pathways regulated by miR-133b in NPC.
Main Methods:
- Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) for miR-133b expression analysis.
- In vitro cell culture experiments with miR-133b mimics and antisense oligonucleotides to assess proliferation.
- Luciferase reporter assays to validate miR-133b targeting of S1PR1.
- Western blot analysis to examine the impact on the STAT3 signaling pathway.
Main Results:
- miR-133b expression was significantly downregulated in NPC tissues compared to adjacent normal tissues.
- Overexpression of miR-133b inhibited NPC cell proliferation, while its knockdown promoted proliferation.
- Sphingosine-1-phosphate receptor 1 (S1PR1) was confirmed as a direct target of miR-133b.
- miR-133b modulated the STAT3 signaling pathway and its downstream protein expression in NPC cells.
Conclusions:
- miR-133b functions as a tumor suppressor in nasopharyngeal carcinoma.
- A novel molecular network involving miR-133b and S1PR1 regulates NPC progression.
- Targeting the miR-133b/S1PR1 axis may offer a potential therapeutic strategy for NPC.
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