Polycistronic RNA polymerase II expression vectors for RNA interference based on BIC/miR-155

Area of Science:

• Molecular Biology
• Gene Regulation
• Biotechnology

Background:

• Vector-based RNA interference (RNAi) is crucial for gene function analysis.
• Existing RNA polymerase III vectors have limitations for certain RNAi applications.

Purpose of the Study:

• To develop novel RNA polymerase II expression vectors for RNAi, termed SIBR vectors.
• To leverage the BIC non-coding RNA and miR-155 precursor for synthetic miRNA expression.
• To enhance the efficiency and flexibility of RNAi applications.

Main Methods:

• Designed SIBR vectors utilizing a modified miR-155 precursor stem-loop and BIC sequences.
• Expressed synthetic miRNAs complementary to target RNAs via RNA polymerase II.
• Investigated intronic expression, coexpression of marker proteins, and polycistronic miRNA expression.

Main Results:

• SIBR vectors efficiently reduced target mRNA and protein expression, comparable to RNA polymerase III vectors.
• Intronic expression, particularly in a two-intron vector, enhanced RNAi efficacy.
• SIBR vectors demonstrated flexibility in expressing multiple distinct miRNAs or tandem copies of a single miRNA.

Conclusions:

• SIBR vectors provide a versatile and efficient platform for RNA polymerase II-driven RNAi.
• The system allows for enhanced gene silencing through coexpression and polycistronic miRNA strategies.
• SIBR vectors represent a valuable advancement for gene function studies and therapeutic RNAi development.