[Bioinformatics-based approach to analyze the regulation of let-7 family by RNA-binding protein Lin28 in hDPSCs]

Bioinformatics was used to analyze the possible mechanism of RNA binding protein Lin28 regulating proliferation of human dental pulp stem cells (hDPSCs).

Lentivirus-mediated stable transfection of Lin28 gene into hDPSCs was performed, and RNA binding protein immunoprecipitation was used to detect the concentration and total amount of mRNA enriched with overexpression of Lin28. The changes of Lin28-enriched mRNA and related pathways were detected by RIP sequencing. The RIP-seq sequencing results were verified by RIP-PCR. The miRNA expression levels of Lin28 and let-7 family members were detected by real-time PCR. TargetScan (http://www.targetscan.org/vert_71/) was used to predict the let-7a relevant target gene mRNA and specific binding sites. Western blot was used to detect the expression levels of let-7a related target genes IGF1R, IRS2, and IGF2BPs family proteins.

RNA binding protein Lin28, as an important mRNA regulatory factor, played a key role in cell growth and development, tissue metabolism, etc. After Lin28 enrichment expression, pri-let-7a/b/c/d/e/f/i/98 and pre-let-7a/b/c/d/e/f/i/98 decreased to different extents. Overexpression of Lin28 could up-regulate the expression levels of let-7-related target genes IGF2BP1 and IGF2BP2 proteins.

Lin28 blocks the processing and maturation of let-7 family through specific complementary binding of pri-let-7 and pre-let-7 in multiple pathways. Lin28 has an indirect regulatory effect on the mRNA of let-7 target genes, and the enriched mRNAs mainly play a role in the growth process, signaling, protein processing, and the translation of the expression of genetic information, which is closely associated with cell growth and proliferation.