Detection of a common chimeric transcript between human chromosomes 7 and 16.

Area of Science:

• Molecular Biology
• Genomics
• RNA Biology

Background:

• Interchromosomal chimeric RNAs typically arise from genomic rearrangements in cancer.
• Understanding non-canonical RNA formation in normal cells is crucial for distinguishing disease-specific events.

Purpose of the Study:

• To computationally detect and experimentally validate an interchromosomal RNA fusion in normal human cells.
• To investigate the origin and characteristics of the identified chimeric RNA transcript.

Main Methods:

• RNA sequencing (RNA-seq) for computational detection of chimeric transcripts.
• Experimental validation using molecular biology techniques across multiple cell lines and tissues.
• Analysis of RNA variants and DNA for rearrangement evidence.

Main Results:

• A novel interchromosomal RNA fusion between ZC3HAV1L and CHMP1A was identified in normal human mammary epithelial cells.
• The ZC3HAV1L-CHMP1A chimeric transcript was experimentally confirmed in various human cells and tissues.
• Three distinct variants of the chimeric RNA were detected, indicating complex alternative splicing.
• The fusion occurred at a novel exon-exon boundary without evidence of DNA rearrangement.

Conclusions:

• The ZC3HAV1L-CHMP1A chimeric RNA is likely generated through a trans-splicing mechanism in normal human cells.
• This finding expands the known mechanisms of chimeric RNA formation beyond genomic rearrangements.
• The complex splicing patterns suggest intricate regulatory processes involving ZC3HAV1L and CHMP1A.