Regulation of telomerase alternative splicing: a target for chemotherapy

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• Telomerase is active in cancer cells but not most normal tissues.
• Human telomerase (hTERT) mRNA undergoes alternative splicing, often yielding nonfunctional products.
• Understanding hTERT splicing is crucial for developing therapies to inhibit telomerase activity.

Purpose of the Study:

• To investigate the mechanisms regulating alternative splicing of hTERT mRNA.
• To identify specific intronic sequences controlling hTERT splicing.
• To explore therapeutic strategies for modulating telomerase activity via splicing manipulation.

Main Methods:

• Utilized minigene constructs containing hTERT exons and flanking intronic sequences.
• Identified a 1.1 kb region with 38 bp repeats near the exon 6/intron junction that regulated splicing.
• Characterized an intronic element in intron 8 that modulated exon skipping.
• Employed antisense oligonucleotides to target the intronic element and alter endogenous hTERT splicing.

Main Results:

• Minigenes with short intronic sequences did not exhibit alternative splicing.
• A specific 1.1 kb intronic region containing repeats restored alternative splicing (exclusion of exons 7 and 8).
• An element within intron 8 significantly modulated this alternative splicing effect.
• Oligonucleotide-mediated targeting of the intron 8 element increased nonfunctional hTERT mRNA production.

Conclusions:

• Discovered novel regulatory elements deep within introns that control mammalian alternative splicing.
• Demonstrated that manipulating hTERT splicing can decrease telomerase activity.
• Highlighted the therapeutic potential of targeting hTERT splicing for cancer treatment and regenerative medicine.