TY - JOUR
T1 - Nonsequential splicing events alter antisense-mediated exon skipping outcome in COL7A1
AU - Ham, Kristin A.
AU - Aung-Htut, May Thandar
AU - Fletcher, Sue
AU - Wilton, Steve D.
PY - 2020/10/2
Y1 - 2020/10/2
N2 - The COL7A1 gene encodes homotrimer fibrils essential for anchoring dermal and epidermal layers, and pathogenic mutations in COL7A1 can cause recessive or dominant dystrophic epidermolysis bullosa. As a monogenic disease gene, COL7A1 constitutes a potential target for antisense oligomer-mediated exon skipping, a therapy applicable to a growing number of other genetic disorders. However, certain characteristics of COL7A1: many exons, low average intron size, and repetitive and guanine-cytosine rich coding sequence, present challenges to the design of specific and effective antisense oligomers. While targeting COL7A1 exons 10 and 73 for excision from the mature mRNA, we discovered that antisense oligomers comprised of 2′-O-methyl modified bases on a phosphorothioate backbone and phosphorodiamidate morpholino oligomers produced similar, but distinctive, splicing patterns including excision of adjacent nontargeted exons and/or retention of nearby introns in some transcripts. We found that the nonsequential splicing of certain introns may alter pre-mRNA processing during antisense oligomer-mediated exon skipping and, therefore, additional studies are required to determine if the order of intron removal influences multiexon skipping and/or intron retention in processing of the COL7A1 pre-mRNA.
AB - The COL7A1 gene encodes homotrimer fibrils essential for anchoring dermal and epidermal layers, and pathogenic mutations in COL7A1 can cause recessive or dominant dystrophic epidermolysis bullosa. As a monogenic disease gene, COL7A1 constitutes a potential target for antisense oligomer-mediated exon skipping, a therapy applicable to a growing number of other genetic disorders. However, certain characteristics of COL7A1: many exons, low average intron size, and repetitive and guanine-cytosine rich coding sequence, present challenges to the design of specific and effective antisense oligomers. While targeting COL7A1 exons 10 and 73 for excision from the mature mRNA, we discovered that antisense oligomers comprised of 2′-O-methyl modified bases on a phosphorothioate backbone and phosphorodiamidate morpholino oligomers produced similar, but distinctive, splicing patterns including excision of adjacent nontargeted exons and/or retention of nearby introns in some transcripts. We found that the nonsequential splicing of certain introns may alter pre-mRNA processing during antisense oligomer-mediated exon skipping and, therefore, additional studies are required to determine if the order of intron removal influences multiexon skipping and/or intron retention in processing of the COL7A1 pre-mRNA.
KW - 2-O-methyl
KW - Antisense oligonucleotides
KW - COL7A1
KW - Dystrophic epidermolysis bullosa
KW - Exon skipping
KW - Intron retention
KW - Morpholino
KW - Splice-switching
UR - http://www.scopus.com/inward/record.url?scp=85093837785&partnerID=8YFLogxK
U2 - 10.3390/ijms21207705
DO - 10.3390/ijms21207705
M3 - Article
C2 - 33081018
AN - SCOPUS:85093837785
SN - 1661-6596
VL - 21
SP - 1
EP - 15
JO - International Journal of Molecular Sciences
JF - International Journal of Molecular Sciences
IS - 20
M1 - 7705
ER -