RNA molecules, methods of producing circular RNA, and treatment methods
The present invention relates to a RNA molecule comprising a first ribozyme, a first ligation sequence, an effector molecule, a second ligation sequence, and a second ribozyme. Methods of producing circular RNA molecules and treatment methods are also disclosed.
1 . An isolated cell comprising a synthetic circular RNA molecule comprising: a first ligation sequence, a synthetic effector molecule positioned 3′ to the first ligation sequence, and a second ligation sequence positioned 3′ to the synthetic effector molecule, wherein the first and second ligation sequences are ligated together, wherein a 3′ portion of the first ligation sequence is complementary to a 5′ portion of the second ligation sequence, wherein prior to the ligation, a 5′-OH end of the first ligation sequence is produced by autocatalyzed cleavage of a 5′ first self-cleaving ribozyme of an exogenous, synthetic linear RNA molecule in the cell and the 2′,3′-cyclic phosphate end of the second ligation sequence is produced by autocatalyzed cleavage of a 3′ second self-cleaving ribozyme of the exogenous, synthetic linear RNA molecule,
wherein the exogenous, synthetic linear RNA molecule comprises:
a portion of the first ligation sequence complementary to a portion of the 5′ first ribozyme and a portion of the second ligation sequence complementary to a portion of the 3′ second ribozyme, such that the portion of the first ligation sequence complementary to the portion of the 5′ first ribozyme is complementary to the portion of the second ligation sequence complementary to the portion of the 3′ second ribozyme.
2 . The isolated cell of claim 1 , wherein the synthetic effector molecule is selected from a group consisting of an RNA sequence that binds a protein;
an RNA sequence that is complementary or has partial complementarity to a microRNA or siRNA; an RNA sequence that hybridizes completely or partially to a cellularly expressed microRNA, siRNA, piRNA, mRNA, IncRNA, ncRNA, or other cellular RNA; an antisense RNA; and an RNA molecule encoding a peptide sequence.
3 . The isolated cell of claim 1 , wherein the cell is capable of producing the synthetic circular RNA molecule at a micromolar concentration.
4 . The isolated cell of claim 1 , wherein the cell is a mammalian cell.
5 . The isolated cell of claim 1 , wherein the first ligation sequence comprises about 21 nucleic acids in length and the second ligation sequence comprises about 26 nucleic acids in length.
6 . The isolated cell of claim 1 , wherein the first ligation sequence comprises the sequence 5′-AACCAUGCCGACUGAUGGCAG-3′ (nucleic acids 58-78 of SEQ ID NO: 2) and the second ligation sequence comprises the sequence 5′-CUGCCAUCAGUCGGCGUGGACUGUAG-3′ (nucleic acids 126-153 of SEQ ID NO: 2).
7 . The isolated cell of claim 1 , wherein the cell further comprises an AAV vector comprising a U6 promoter, a nucleic acid sequence encoding a 5′ ribozyme, a nucleic acid sequence encoding the first ligation sequence, a nucleic acid sequence encoding the synthetic effector molecule, a nucleic acid sequence encoding the second ligation sequence, and a nucleic acid sequence encoding a 3′ ribozyme.
8 . The isolated cell of claim 4 , wherein the mammalian cell is a human cell.
9 . The isolated cell of claim 1 , wherein the cell comprises an endogenous RtcB ligase.
10 . The isolated cell of claim 1 , wherein the cell comprises an exogenous RtcB ligase.
11 . The isolated cell of claim 7 , wherein the 5′ ribozyme and the 3′ ribozyme are each independently selected from the group consisting of Hammerhead, Hairpin, Hepatitis Delta Virus (“HDV”), Varkud Satellite (“VS”), Vg1, glucosamine-6-phosphate synthase (“glmS”), Twister, Twister Sister, Hatchet, Pistol ribozymes, engineered synthetic ribozymes, or derivatives thereof.