Oral Presentation ASSCR, AGCTS, ISCT ANZ and Friends Joint Scientific Conference 2019

Antisense oligonucleotide mediated knockdown of RNA-binding proteins SAM68 and hnRNP-A1 to modulate expression of the survival motor neuron 2 gene. (#28)

Ianthe L Pitout 1 2 3 , Loren L Flynn 2 3 , Sue Fletcher 1 2 , Steve D Wilton 2 3
  1. Centre for Comparative Genomics, Murdoch, Western Australia, Australia
  2. Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Perth, Western Australia, Australia
  3. Perron Institute for Neurological and Translational Science, Perth, Western Australia, Australia

Spinal muscular atrophy (SMA), is a severe childhood disease most commonly caused by the homozygous loss of the survival motor neuron 1 (SMN1) gene that encodes an essential protein, SMN. A homologous gene, SMN2 provides insufficient levels of SMN and is unable to compensate for the loss of SMN1. A single nucleotide change in SMN2 exon 7 creates a splice silencer, leading to the predominant production of truncated transcripts missing exon 7 that encode a non-functional SMN protein. Pre-mRNA splicing of SMN2 exon 7 is modulated by RNA-binding proteins SAM68 and hnRNP-A1 that promote exon 7 exclusion from the mature SMN2 transcript. Targeted knockdown of SAM68 and/or hnRNP-A1 has potential to increase the amount of functional SMN produced by the sub-optimal SMN2 gene. Antisense oligonucleotides designed to knockdown SAM68 and hnRNP-A1 were delivered individually and in combination with Anti ISS-N1, an antisense compound targeting SMN2 directly, into SMA patient fibroblasts. Gene transcript and functional protein analysis showed SAM68 and hnRNP-A1 knockdown subsequently increased functional SMN production in an additive manner when combined with Anti ISS-N1. There is thus potential for antisense therapeutics targeting SAM68 and/or hnRNP-A1 to be used to augment the action of Anti ISS-N1 as a combinatorial treatment for SMA.

 

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