Linear isoforms of the long noncoding RNA CDKN2B-AS1 regulate the c-myc-enhancer binding factor RBMS1

Area of Science:

• Genetics
• Molecular Biology
• RNA Biology

Background:

• Variants in CDKN2B-AS1 (ANRIL) are associated with type 2 diabetes, atherosclerosis, and cancer.
• Previous studies showed proximal ANRIL transcripts regulate glucose and lipid metabolism genes.
• The regulatory role of distal ANRIL transcripts at physiological concentrations remained unclear.

Purpose of the Study:

• To identify specific genes regulated by distal CDKN2B-AS1 (ANRIL) transcripts.
• To elucidate the mechanism of ANRIL-mediated gene regulation in relation to diabetes.

Main Methods:

• Utilized inducible short hairpin RNA in T-Rex HEK293 cells to silence CDKN2B-AS1.
• Performed genome-wide mRNA expression analysis at defined time points.
• Confirmed target gene downregulation at transcript and protein levels in HeLa cells using RNA immunoprecipitation.

Main Results:

• Identified RBMS1 as a direct target gene of distal CDKN2B-AS1 transcripts.
• Demonstrated downregulation of RBMS1 at transcript and protein levels, independent of cell type and cis-regulatory effects.
• Showed direct binding of CDKN2B-AS1 transcripts to RBMS1 mRNA.

Conclusions:

• Distal and proximal CDKN2B-AS1 (ANRIL) transcripts possess distinct gene regulatory functions.
• CDKN2B-AS1 directly regulates RBMS1, a cell cycle suppressor, via transcript binding.
• These regulatory functions are independent of circular ANRIL isoforms and CDKN2A/2B genes.