Long non-coding RNA

Definition

Long non-coding RNAs (lncRNAs) are a class of RNA molecules that exceed 200 nucleotides in length and do not encode proteins. These RNA molecules play vital roles in the regulation of gene expression, cellular processes, and chromatin organization. Unlike messenger RNAs (mRNAs), which are templates for protein synthesis, lncRNAs exert their functions primarily through interactions with DNA, RNA, and proteins, influencing various biological activities.

5 Must Know Facts For Your Next Test

1. lncRNAs are involved in a variety of cellular functions including gene silencing, transcriptional regulation, and chromatin remodeling.
2. Many lncRNAs are tissue-specific and can be used as biomarkers for certain diseases due to their differential expression patterns.
3. The mechanism of action for lncRNAs often involves forming ribonucleoprotein complexes that can interact with chromatin-modifying proteins to influence gene activity.
4. lncRNAs can act as molecular sponges, sequestering microRNAs and preventing them from interacting with their target mRNAs.
5. Research has shown that lncRNAs can also play roles in development, stem cell biology, and cancer progression by modulating key signaling pathways.

Review Questions

• How do long non-coding RNAs influence gene expression at the molecular level?
  • Long non-coding RNAs influence gene expression through various mechanisms such as recruiting chromatin-modifying complexes to specific genomic regions, thereby altering chromatin structure and accessibility. They can also interact directly with transcription factors or RNA polymerase, affecting transcription initiation and elongation. Additionally, lncRNAs may act as molecular scaffolds, facilitating the assembly of multi-protein complexes that regulate transcriptional activity.
• Discuss the significance of long non-coding RNAs in disease contexts, particularly cancer.
  • Long non-coding RNAs have gained attention for their roles in various diseases, especially cancer. Many lncRNAs are found to be aberrantly expressed in tumor tissues compared to normal tissues. Their involvement in processes like proliferation, apoptosis, and metastasis highlights their potential as therapeutic targets and biomarkers. Some lncRNAs can promote oncogenesis by regulating pathways that control cell growth or suppressing tumor suppressor genes.
• Evaluate the potential applications of long non-coding RNAs in personalized medicine.
  • The unique expression profiles of long non-coding RNAs across different tissues and conditions offer promising applications in personalized medicine. By identifying specific lncRNA signatures associated with particular diseases or responses to treatments, clinicians could improve diagnostic accuracy and tailor therapeutic strategies. Moreover, as our understanding of the functional roles of lncRNAs expands, they could serve as novel therapeutic targets or agents in gene therapy approaches aimed at modulating disease-related pathways.

Related terms

MicroRNA: Small, non-coding RNA molecules that regulate gene expression by binding to complementary sequences in target mRNAs, leading to their degradation or inhibition of translation.

Enhancer RNA: RNA molecules transcribed from enhancer regions of DNA that play a role in regulating the expression of nearby genes by enhancing transcriptional activity.

Chromatin: The complex of DNA and proteins that forms chromosomes, playing a key role in regulating gene expression through structural modifications.