Tomoki T. Nomakuchi

Tomoki T. Nomakuchi
B.S. Hofstra University, 2010

5th Year MSTP
3rd Year Molecular Genetics and Microbiology Graduate Student

Advisor: Adrian Krainer, PhD

Cold Spring Harbor Laboratory

Graduate Program: Molecular Genetics & Microbiology

Title:  Antisense-oligonucleotide-directed inhibition of nonsense-mediated mRNA decay 

Abstract: 

RNA-based therapeutic approaches have become increasingly promising, as demonstrated by recent remarkable progress in the development of antisense oligonucleotides (ASOs) and stop-codon read-through drugs as therapeutics for various genetic diseases. Nonsense mutations, which account for a large proportion of pathogenic genetic lesions, can be partially overcome by suppressing premature stop codons (PTCs) using read-through drugs, such as ataluren or aminoglycosides. Nonsense-mediated mRNA decay (NMD) is a cellular quality-control mechanism that degrades mRNAs that harbor PTCs. In the context of genetic diseases caused by nonsense mutations, NMD can worsen the clinical outcome by degrading transcripts that code for truncated but semi-functional proteins, or by reducing the efficacy of read-through therapy. NMD is highly dependent on the exonjunction complex (EJC), which assembles upstream of exon-exon junctions at the completion of pre-mRNA splicing. We have designed ASOs that target presumptive EJC sites and suppress NMD of ß-globin and MECP2 transcripts with PTCs, with increases in gene products seen both at the transcript and protein levels. In addition, we have systematically tested multiple EJC-targeting ASOs to stabilize CFTR transcript with the W1282X nonsense mutation, a common mutation in cystic fibrosis patients. Data presented here point to a potential to develop this technique more broadly as a therapy for genetic diseases caused by nonsense mutations.

Awards:

Travel grant to attend the 11th Annual Meeting of the Oligonucleotide Therapeutics Society, in Leiden, the Netherlands - 2015.

Publications:

(MSTP-supported publications indicated with an *)

Nomakuchi T, Rigo F, Aznarez I, Krainer AR. Antisense-oligonucleotide-directed inhibition of nonsense-mediated mRNA decay. Nature Biotechnology

*Sahashi K, Ling KKY, Hua Y, Wilkinson JE, Nomakuchi T, Rigo F, Hung G, Xu D, Jiang Y-P, Lin RZ, Ko C-P, Bennett CF, Krainer AR. (2013). Pathological impact of SMN2 mis-splicing in adult SMA mice. EMBO Molecular Medicine. 5: 1586-601 PMCID: 3799581.