TY - JOUR

T1 - Cholesterol Conjugates of Small Interfering RNA: Linkers and Patterns of Modification

AU - Chernikov, Ivan V.

AU - Ponomareva, Ul’yana A.

AU - Meschaninova, Mariya I.

AU - Bachkova, Irina K.

AU - Vlassov, Valentin V.

AU - Zenkova, Marina A.

AU - Chernolovskaya, Elena L.

N1 - This research was funded by the Russian Science Foundation (grant №19-14-00251) and project ICBFM SB RAS №121031300044-5 (synthesis of control siRNAs).

PY - 2024/2

Y1 - 2024/2

N2 - Cholesterol siRNA conjugates attract attention because they allow the delivery of siRNA into cells without the use of transfection agents. In this study, we compared the efficacy and duration of silencing induced by cholesterol conjugates of selectively and totally modified siRNAs and their heteroduplexes of the same sequence and explored the impact of linker length between the 3′ end of the sense strand of siRNA and cholesterol on the silencing activity of “light” and “heavy” modified siRNAs. All 3′-cholesterol conjugates were equally active under transfection, but the conjugate with a C3 linker was less active than those with longer linkers (C8 and C15) in a carrier-free mode. At the same time, they were significantly inferior in activity to the 5′-cholesterol conjugate. Shortening the sense strand carrying cholesterol by two nucleotides from the 3′-end did not have a significant effect on the activity of the conjugate. Replacing the antisense strand or both strands with fully modified ones had a significant effect on silencing as well as improving the duration in transfection-mediated and carrier-free modes. A significant 78% suppression of MDR1 gene expression in KB-8-5 xenograft tumors developed in mice promises an advantage from the use of fully modified siRNA cholesterol conjugates in combination chemotherapy.

AB - Cholesterol siRNA conjugates attract attention because they allow the delivery of siRNA into cells without the use of transfection agents. In this study, we compared the efficacy and duration of silencing induced by cholesterol conjugates of selectively and totally modified siRNAs and their heteroduplexes of the same sequence and explored the impact of linker length between the 3′ end of the sense strand of siRNA and cholesterol on the silencing activity of “light” and “heavy” modified siRNAs. All 3′-cholesterol conjugates were equally active under transfection, but the conjugate with a C3 linker was less active than those with longer linkers (C8 and C15) in a carrier-free mode. At the same time, they were significantly inferior in activity to the 5′-cholesterol conjugate. Shortening the sense strand carrying cholesterol by two nucleotides from the 3′-end did not have a significant effect on the activity of the conjugate. Replacing the antisense strand or both strands with fully modified ones had a significant effect on silencing as well as improving the duration in transfection-mediated and carrier-free modes. A significant 78% suppression of MDR1 gene expression in KB-8-5 xenograft tumors developed in mice promises an advantage from the use of fully modified siRNA cholesterol conjugates in combination chemotherapy.

KW - MDR1 gene

KW - chemical modifications

KW - cholesterol conjugate

KW - duration of silencing

KW - nuclease resistance

KW - siRNA

KW - Humans

KW - Animals

KW - Mice

KW - RNA, Small Interfering/metabolism

KW - RNA, Double-Stranded

KW - Cholesterol

KW - RNA Interference

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85186263553&origin=inward&txGid=e226fe7f8426aa3c655f038aee62a964

UR - https://www.webofscience.com/wos/woscc/full-record/WOS:001172373900001

UR - https://www.mendeley.com/catalogue/c8eb5ce7-960a-3831-b02c-85bfd229e35a/

U2 - 10.3390/molecules29040786

DO - 10.3390/molecules29040786

M3 - Article

C2 - 38398538

VL - 29

JO - Molecules

JF - Molecules

SN - 1420-3049

IS - 4

M1 - 786

ER -