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Published on: August 21, 2019
MicroRNA 3' end nucleotide modification patterns and arm selection preference in liver tissues.
Sung-Chou Li1, Kuo-Wang Tsai, Hung-Wei Pan
1Genomics Research Center, Academia Sinica, Taipei, Taiwan.
BMC Systems Biology
|January 4, 2013
Summary
MicroRNA (miRNA) 3' end modifications are specific to miRNA type and tissue, with lower modification rates in HBV-associated liver tumors. Different liver tissues also show distinct preferences for miRNA arm selection during maturation.
Area of Science:
- Molecular Biology
- Genetics
- Biochemistry
Background:
- MicroRNA (miRNA) gene expression involves complex maturation steps.
- Recent research has illuminated miRNA maturation but also sparked debate on its mechanisms.
Purpose of the Study:
- To investigate miRNA biogenesis pathways in normal and tumor liver tissues.
- To analyze miRNA 3' end modifications and arm selection preferences.
Main Methods:
- Downloaded and quantified small RNA sequence reads from NCBI SRA.
- Analyzed miRNA expression profiles from normal and tumor liver tissues.
- Examined miRNA 3' end nucleotide modifications and 5p/3p arm expression ratios.
Main Results:
- Adenine is the predominant nucleotide modification at miRNA 3' ends (>50%), with uracil significant in specific miRNA types.
- HBV-associated liver tumor tissues exhibit reduced miRNA 3' end nucleotide modification rates.
- Liver tissues display distinct preferences for either the 5p or 3p arm of pre-miRNAs, deviating from the constant arm ratio theory.
Conclusions:
- MiRNA 3' end modifications are miRNA-specific and vary between normal and tumor liver tissues.
- Tissue-specific arm selection suggests alternative mechanisms in miRNA biogenesis beyond established theories.
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