Using Dual-Luciferase Assays to Identify the Role of Non-Coding RNAs in Disease

In recent years, non-coding RNAs—especially microRNAs (miRNAs) and long non-coding RNAs (lncRNAs)—have emerged as powerful regulators of cellular behavior. These molecules modulate gene expression, often by targeting mRNAs for translational suppression or degradation. Two recent studies—one focused on osteoarthritis and the other on 5-Fu-resistant colorectal cancer—illustrate how these non-coding, regulatory RNAs operate within disease-relevant signaling networks, providing new points for therapeutic intervention.

lncRNA, long noncoding RNA

Both studies use the pmirGLO Dual-Luciferase miRNA Target Expression Vector to evaluation predicted miRNA activity.  This dual-luciferase system offers a clean and quantifiable way to validate miRNA–mRNA interactions using a simple bioluminescent readout. By cloning the 3´ untranslated regions (UTRs) of suspected targets downstream of a firefly luciferase reporter and normalizing against Renilla luciferase, researchers can rapidly confirm whether a miRNA directly regulates its target.

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LncRNA: The Long and Short of “Junk RNA”

The Central Dogma and Junk DNA

lncRNA, long noncoding RNA

On September 19, 1957, Francis Crick delivered a lecture during a symposium at University College London, titled “Protein Synthesis”. The lecture was published a year later (1); in it, Crick quotes his colleague James Watson as saying, “The most significant thing about the nucleic acids is that we don’t know what they can do.” In contrast, Crick argued that proteins play a central, indispensable role as enzymes within the cell that catalyze a variety of chemical reactions. He believed that the main role of genetic material was to control the synthesis of proteins, although the mechanism of that process was not known.

Crick’s hypothesis came to be known as the central dogma of molecular biology, and it was immortalized in his hand-written notes that described the flow of information from DNA to RNA to proteins. This achievement was all the more remarkable, considering that messenger RNAs were completely unknown at that time, and very little was known about how the cellular translational machinery functioned within the cytoplasm to synthesize proteins. Although the later discovery of retroviruses appeared to challenge Crick’s central dogma, he explained quite succinctly that his original statement had simply been misunderstood, and that information could flow in both directions between DNA and RNA (2).

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