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bioRxiv · 10.1101/2020.09.18.302984

Splice switching oligonucleotide mediated gene knockdown in B cells and plasma cells

Delpy, L.·Marchalot, A.·Lambert, J.-M.·Boyer, F.·Pollet, J.·Cook-Moreau, J.·Feuillard, J.·Faumont, N.
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Abstract

The need to identify new therapeutic approaches to the treatment of cancers of the B lymphoid lineage is crucial. Unlike CRISPR/Cas technology, antisense strategies result in transient modifications of gene expression and lack mutagenic effects at the DNA level. Here, we provide evidence for efficient knockdown of c-REL and RELA expression after treatment with splice switching antisense oligonucleotides (SSO) inducing exon skipping and reading frameshifts. We also developed a tool to facilitate the choice of exons for on purpose inhibition of mouse and human gene expression. Interestingly, treatments with morpholino SSO targeting the c-REL exon 2 donor splice site or RELA exon 5 acceptor splice site elicited very efficient knockdown in diffuse large B cell lymphoma (DLBCL) cell lines and antibody-secreting cells derived from primary human B cells. Consistent with the clinical relevance of c-REL activation in DLBCLs, treatment with c-REL SSO induced major alterations in NF-{kappa}B and TNF signalling pathways and strongly decreased cell viability. Altogether, SSO-mediated knockdown is a powerful approach to transiently inhibit the expression of given genes in B-lineage cells that should pave the way for cancer treatments, provided optimized ligand-conjugations for in vivo delivery. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=169 SRC="FIGDIR/small/302984v1_ufig1.gif" ALT="Figure 1"> View larger version (31K): org.highwire.dtl.DTLVardef@170de4forg.highwire.dtl.DTLVardef@113229corg.highwire.dtl.DTLVardef@145377forg.highwire.dtl.DTLVardef@13e8c1e_HPS_FORMAT_FIGEXP M_FIG C_FIG

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Delpy, L., Marchalot, A., Lambert, J.-M., Boyer, F., Pollet, J., Cook-Moreau, J., Feuillard, J., Faumont, N.. 2020-09-18. Splice switching oligonucleotide mediated gene knockdown in B cells and plasma cells. https://doi.org/10.1101/2020.09.18.302984

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