Soudah, Terese Mogilevsky, Maxim Karni, Rotem Yavin, Eylon CLIP6-PNA-Peptide Conjugates: Non-Endosomal Delivery of Splice Switching Oligonucleotides Efficient delivery of oligonucleotides still remains a challenge in the field of oligonucleotide based therapy. Peptide nucleic acid (PNA), a DNA analogue that is typically synthesized by solid phase peptide chemistry, has been conjugated to a variety of cell penetrating peptides (CPP) as a means of improving its cellular uptake. These CPPs typically deliver their cargoes into cells by an endosomal-dependent mechanism resulting in lower bioavailability of the cargo. Herein, we designed and synthesized PNA–peptide conjugates as splice switching oligonucleotides (SSO) targeting the Mnk2 gene, a therapeutic target in cancer. In humans, the MKNK2 gene, is alternatively spliced, generating isoforms with opposite biological activities: Mnk2a and Mnk2b. It was found that the Mnk2a isoform is down-regulated in breast, lung, brain, and colon tumors and is a tumor suppressor, whereas MnK2b is oncogenic. We have designed and synthesized PNAs that were conjugated to either of the following peptides: a nuclear localization sequence (NLS) or a cytosol localizing internalization peptide (CLIP6). CLIP6-PNA demonstrates effective cellular uptake and exclusively employs a nonendosomal mechanism to cross the cellular membranes of glioblastoma cells (U87). Simple incubation of PNA–peptide conjugates in human glioblastoma cells up-regulates the Mnk2a isoform leading to cancer cell death. localization sequence;cancer cell death;CPP;glioblastoma cells up-regulates;uptake;endosomal-dependent mechanism;Splice Switching Oligonucleotides Efficient delivery;glioblastoma cells;MKNK 2 gene;phase peptide chemistry;cargo;MnK 2b;tumor suppressor;nonendosomal mechanism;Non-Endosomal Delivery;oligonucleotide;Mnk 2a isoform;Mnk 2 gene;SSO;cytosol localizing internalization peptide;DNA analogue;Mnk 2a;Mnk 2b;colon tumors;conjugate;CLIP 6-PNA Conjugates;NLS 2017-12-06
    https://acs.figshare.com/articles/journal_contribution/CLIP6-PNA-Peptide_Conjugates_Non-Endosomal_Delivery_of_Splice_Switching_Oligonucleotides/5677552
10.1021/acs.bioconjchem.7b00638.s001