Nucleic acid, composition and conjugate comprising the same, and preparation method and use thereof

1. A siRNA, comprising a sense strand and an antisense strand, each nucleotide in the siRNA being independently a modified or unmodified nucleotide, wherein the sense strand comprises a nucleotide sequence I, and the antisense strand comprises a nucleotide sequence II; the nucleotide sequence I and the nucleotide sequence II are at least partly reverse complementary to form a double stranded region; wherein the nucleotide sequence I comprises a nucleotide sequence A, which has the same length as the nucleotide sequence shown in SEQ ID NO: 1 with no more than 3 nucleotide differences; and the nucleotide sequence II comprises a nucleotide sequence B, which has the same length as the nucleotide sequence shown in SEQ ID NO: 2 with no more than 3 nucleotide differences:

(SEQ ID NO: 1)

5′-UGCUAUGCCUCAUCUUCUZ-3′;

(SEQ ID NO: 2)

5′-Z′AGAAGAUGAGGCAUAGCA-3′;

wherein,

Z is A; Z′ is U; and

the nucleotide sequence A comprises a nucleotide Z A at the position corresponding to Z; the nucleotide sequence B comprises a nucleotide Z′ B at the position corresponding to Z′; the nucleotide Z′B is the first nucleotide at 5′ terminal of the antisense strand,

wherein each nucleotide in the sense strand and the antisense strand is independently a fluoro modified nucleotide or a non-fluoro modified nucleotide; wherein the fluoro modified nucleotides are in the nucleotide sequences A and B; and in the direction from 5′ terminal to 3′ terminal, the nucleotides at positions 7, 8 and 9 of the nucleotide sequence A are fluoro modified nucleotides; and in the direction from 5′ terminal to 3′ terminal, the nucleotides at positions 2, 6, 14 and 16 of the nucleotide sequence B are fluoro modified nucleotides.

2. The siRNA according to claim 1 , wherein the nucleotide sequence A is a nucleotide sequence shown in SEQ ID NO: 3; and the nucleotide sequence B is a nucleotide sequence shown in SEQ ID NO: 4:

(SEQ ID NO: 3)

5′-UGCUAUGCCUCAUCUUCUZ A -3′;

(SEQ ID NO: 4)

5′-Z′ B AGAAGAUGAGGCAUAGCA-3′;

wherein Z′B is the first nucleotide at 5′ terminal of the antisense strand; Z A is selected from A, U, G or C, and Z′B is a nucleotide complementary to Z A .

3. The siRNA according to claim 1 , wherein the nucleotide sequence I further comprises a nucleotide sequence III, and the nucleotide sequence II further comprises a nucleotide sequence IV; the nucleotide sequence III and the nucleotide sequence IV independently of one another are 1-4 nucleotides in length; the nucleotide sequence III is linked to 5′ terminal of the nucleotide sequence A; the nucleotide sequence IV is linked to 3′ terminal of the nucleotide sequence B; and the nucleotide sequence III and the nucleotide sequence IV have the same length and are substantially reverse complementary or completely reverse complementary; the “substantially reverse complementary” means that there is no more than 1 base mispairing between two nucleotide sequences; the “completely reverse complementary” means that there is no mispairing between two nucleotide sequences.

4. The siRNA according to claim 3 , wherein the nucleotide sequence III and the nucleotide sequence IV both are of 1 nucleotide in length, and the base of the nucleotide sequence III is G;

the nucleotide sequence III and the nucleotide sequence IV both are 2 nucleotides in length; in the direction from 5′ terminal to 3′ terminal, the base composition of the nucleotide sequence III is AG;

the nucleotide sequence III and the nucleotide sequence IV both are 3 nucleotides in length; in the direction from 5′ terminal to 3′ terminal, the base composition of the nucleotide sequence III is AAG; or

the nucleotide sequence III and the nucleotide sequence IV both are 4 nucleotides in length; in the direction from 5′ terminal to 3′ terminal, the base composition of the nucleotide sequence III is CAAG.

5. The siRNA according to claim 1 , wherein the nucleotide sequence II further comprises a nucleotide sequence V, which is 1-3 nucleotides in length and is linked to 3′ terminal of the antisense strand, thereby forming a 3′ overhang of the antisense strand.

6. The siRNA according to claim 1 , wherein the sense strand of the siRNA comprises the nucleotide sequence shown in SEQ ID NO: 3, and the antisense strand comprises the nucleotide sequence shown in SEQ ID NO: 5:

(SEQ ID NO: 3)

5'-UGCUAUGCCUCAUCUUCUZ A -3';

(SEQ ID NO: 5)

5'-Z' B AGAAGAUGAGGCAUAGCAGC-3';

or

the sense strand of the siRNA comprises the nucleotide sequence shown in SEQ ID NO: 3, and the antisense strand comprises the nucleotide sequence shown in SEQ ID NO: 6:

(SEQ ID NO: 3)

5′-UGCUAUGCCUCAUCUUCUZ A -3′;

(SEQ ID NO: 6)

5′-Z′ B AGAAGAUGAGGCAUAGCAUU-3′;

wherein the nucleotide Z′ B is the first nucleotide at 5′ terminal of the antisense strand; Z A is selected from A, U, G or C; and Z′ B is a nucleotide complementary to Z A .

7. The siRNA according to claim 1 , wherein each non-fluoro modified nucleotide is a methoxy modified nucleotide, wherein the methoxy modified nucleotide refers to a nucleotide formed by substituting the 2′-hydroxy of the ribose group of the nucleotide with a methoxy group.

8. The siRNA according to claim 1 , wherein in the direction from 5′ terminal to 3′ terminal, the nucleotides at positions 5, 7, 8 and 9 of the nucleotide sequence A in the sense strand of the siRNA are fluoro modified nucleotides, and the nucleotides at the other positions in the sense strand of the siRNA are methoxy modified nucleotides; and in the direction from 5′ terminal to 3′ terminal, the nucleotides at positions 2, 6, 8, 9, 14 and 16 of the nucleotide sequence B in the antisense strand of the siRNA are fluoro modified nucleotides, and the nucleotides at the other positions in the antisense strand of the siRNA are methoxy modified nucleotides; or

in the direction from 5′ terminal to 3′ terminal, the nucleotides at positions 5, 7, 8 and 9 of the nucleotide sequence A in the sense strand of the siRNA are fluoro modified nucleotides, and the nucleotides at the other positions in the sense strand of the siRNA are methoxy modified nucleotides; and in the direction from 5′ terminal to 3′ terminal, the nucleotides at positions 2, 6, 14 and 16 of the nucleotide sequence B in the antisense strand of the siRNA are fluoro modified nucleotides, and the nucleotides at the other positions in the antisense strand of the siRNA are methoxy modified nucleotides; or

in the direction from 5′ terminal to 3′ terminal, the nucleotides at positions 7, 8 and 9 of the nucleotide sequence A in the sense strand of the siRNA are fluoro modified nucleotides, and the nucleotides at the other positions in the sense strand of the siRNA are methoxy modified nucleotides; and in the direction from 5′ terminal to 3′ terminal, the nucleotides at positions 2, 6, 14 and 16 of the nucleotide sequence B in the antisense strand of the siRNA are fluoro modified nucleotides, and the nucleotides at the other positions in the antisense strand of the siRNA are methoxy modified nucleotides.

9. The siRNA according to claim 1 , wherein the siRNA is siHBVS3, siHBVS4, siHBVS5, or siHBVS6:

siHBVS3

Sense strand:

(SEQ ID NO: 9)

5′-UmGmCmUmAmUmGfCfCfUmCmAmUmCmUmUmCmUmAm-3′,

Antisense strand:

(SEQ ID NO: 10)

5′-UmAfGmAmAmGfAmUmGmAmGmGmCmAfUmAfGmCmAmGmCm-3′,

siHBVS4

Sense strand:

(SEQ ID NO: 9)

5′-UmGmCmUmAmUmGfCfCfUmCmAmUmCmUmUmCmUmAm-3′,

Antisense strand:

(SEQ ID NO: 11)

5′-UmAfGmAmAmGfAmUmGmAmGmGmCmAfUmAfGmCmAmUmUm-3′,

siHBVS5

Sense strand:

(SEQ ID NO: 12)

5′-UmGmCmUmAfUmGfCfCfUmCmAmUmCmUmUmCmUmAm-3′,

Antisense strand:

(SEQ ID NO: 13)

5′-UmAfGmAmAmGfAmUfGfAmGmGmCmAfUmAfGmCmAmGmCm-3′,

siHBVS6

Sense strand:

(SEQ ID NO: 12)

5′-UmGmCmUmAfUmGfCfCfUmCmAmUmCmUmUmCmUmAm-3′,

Antisense strand:

(SEQ ID NO: 14)

5′-UmAfGmAmAmGfAmUfGfAmGmGmCmAfUmAfGmCmAmUmUm-3′,

wherein C, G, U, and A represent the base composition of the nucleotides; m represents that the nucleotide adjacent to the left side of the letter m is a methoxy modified nucleotide; f represents that the nucleotide adjacent to the left side of the letter f is a fluoro modified nucleotide.

10. The siRNA according to claim 1 , wherein in the siRNA, at least one phosphate group is a phosphorothioate group, and the phosphorothioate linkage exists in at least one of the following positions:

the position between the first and second nucleotides at 5′ terminal of the sense strand;

the position between the second and third nucleotides at 5′ terminal of the sense strand;

the position between the first and second nucleotides at 3′ terminal of the sense strand;

the position between the second and third nucleotides at 3′ terminal of the sense strand;

the position between the first and second nucleotides at 5′ terminal of the antisense strand;

the position between the second and third nucleotides at 5′ terminal of the antisense strand;

the position between the first and second nucleotides at 3′ terminal of the antisense strand; and

the position between the second and third nucleotides at 3′ terminal of the antisense strand.

11. The siRNA according to claim 1 , wherein the siRNA is siHBVS7, siHBVS8, siHBVS9, or siHBVS10:

siHBVS7

Sense strand:

(SEQ ID NO: 15)

5′-UmsGmsCmUmAmUmGfCfCfUmCmAmUmCmUmUmCmUmAm-3′,

AntiSense strand:

(SEQ ID NO: 16)

5′-UmsAfsGmAmAmGfAmUmGmAmGmGmCmAfUmAfGmCmAmsGms

Cm-3′,

siHBVS8

Sense strand:

(SEQ ID NO: 15)

5′-UmsGmsCmUmAmUmGfCfCfUmCmAmUmCmUmUmCmUmAm-3′,

AntiSense strand:

(SEQ ID NO: 17)

5′-UmsAfsGmAmAmGfAmUmGmAmGmGmCmAfUmAfGmCmAmsUms

Um-3′,

siHBVS9

Sense strand:

(SEQ ID NO: 18)

5′-UmsGmsCmUmAfUmGfCfCfUmCmAmUmCmUmUmCmUmAm-3′,

AntiSense strand:

(SEQ ID NO: 19)

5′-UmsAfsGmAmAmGfAmUfGfAmGmGmCmAfUmAfGmCmAmsGms

Cm-3′,

siHBVS10

Sense strand:

(SEQ ID NO: 18)

5′-UmsGmsCmUmAfUmGfCfCfUmCmAmUmCmUmUmCmUmAm-3′,

Antisense strand:

(SEQ ID NO: 20)

5′-UmsAfsGmAmAmGfAmUfGfAmGmGmCmAfUmAfGmCmAmsUms

Um-3′,

wherein C, G, U, and A represent the base composition of the nucleotides; m represents that the nucleotide adjacent to the left side of the letter m is a methoxy modified nucleotide; f represents that the nucleotide adjacent to the left side of the letter f is a fluoro modified nucleotide; s represents that the two nucleotides adjacent to both sides of the letter s are linked by a phosphorothioate linkage.

12. The siRNA according to claim 1 , wherein the nucleotide at 5′-terminal of the antisense strand is a 5′-phosphate nucleotide or a 5′-phosphate analogue modified nucleotide, wherein the 5′-phosphate nucleotide is a nucleotide having a structure as shown by Formula (2); and the 5′-phosphate analogue modified nucleotide is a nucleotide as shown by any one of Formulae (3) to (6):

wherein R is selected from H, OH, methoxy, or F; “Base” represents a base selected from A, U, C, G, or T.

13. The siRNA according to claim 1 , wherein the siRNA is siHBVS11, siHBVS12, siHBVS13, siHBVS14, siHBVS15, siHBVS16, siHBVS17, or siHBVS18:

siHBVS11

Sense strand:

(SEQ ID NO: 9)

5′-UmGmCmUmAmUmGfCfCfUmCmAmUmCmUmUmCmUmAm-3′,

Antisense strand:

(SEQ ID NO: 21)

5′-P1-UmAfGmAmAmGfAmUmGmAmGmGmCmAfUmAfGmCmAm

GmCm-3′,

siHBVS12

Sense strand:

(SEQ ID NO: 9)

5′-UmGmCmUmAmUmGfCfCfUmCmAmUmCmUmUmCmUmAm-3′,

Antisense strand:

(SEQ ID NO: 22)

5′-P1-UmAfGmAmAmGfAmUmGmAmGmGmCmAfUmAfGmCmAm

UmUm-3′,

siHBVS13

Sense strand:

(SEQ ID NO: 12)

5′-UmGmCmUmAfUmGfCfCfUmCmAmUmCmUmUmCmUmAm-3′,

Antisense strand:

(SEQ ID NO: 23)

5′-P1-UmAfGmAmAmGfAmUfGfAmGmGmCmAfUmAfGmCmAm

GmCm-3′,

siHBVS14

Sense strand:

(SEQ ID NO: 12)

5′-UmGmCmUmAfUmGfCfCfUmCmAmUmCmUmUmCmUmAm-3′,

Antisense strand:

(SEQ ID NO: 24)

5′-P1-UmAfGmAmAmGfAmUfGfAmGmGmCmAfUmAfGmCmAmUm

Um-3′,

siHBVS15

Sense strand:

(SEQ ID NO: 15)

5′-UmsGmsCmUmAmUmGfCfCfUmCmAmUmCmUmUmCmUmAm-3′,

Antisense strand:

(SEQ ID NO: 25)

5′-P1-UmsAfsGmAmAmGfAmUmGmAmGmGmCmAfUmAfGmCmAms

GmsCm-3′,

siHBVS16

Sense strand:

(SEQ ID NO: 15)

5′-UmsGmsCmUmAmUmGfCfCfUmCmAmUmCmUmUmCmUmAm-3′,

Antisense strand:

(SEQ ID NO: 26)

5′-P1-UmsAfsGmAmAmGfAmUmGmAmGmGmCmAfUmAfGmCmAms

UmsUm-3′,

siHBVS17

Sense strand:

(SEQ ID NO: 18)

5′-UmsGmsCmUmAfUmGfCfCfUmCmAmUmCmUmUmCmUmAm-3′,

Antisense strand:

(SEQ ID NO: 27)

5′-P1-UmsAfsGmAmAmGfAmUfGfAmGmGmCmAfUmAfGmCmAms

GmsCm-3′,

siHBVS18

Sense strand:

(SEQ ID NO: 18)

5′-UmsGmsCmUmAfUmGfCfCfUmCmAmUmCmUmUmCmUmAm-3′,

Antisense strand:

(SEQ ID NO: 28)

5′-P1-UmsAfsGmAmAmGfAmUfGfAmGmGmCmAfUmAfGmCmAms

UmsUm-3′;

wherein C, G, U, and A represent the base composition of the nucleotides; m represents that the nucleotide adjacent to the left side of the letter m is a methoxy modified nucleotide; f represents that the nucleotide adjacent to the left side of the letter f is a fluoro modified nucleotide; s represents that the two nucleotides adjacent to both sides of the letter s are linked by a phosphorothioate linkage; P1 represents that the nucleotide adjacent to the right side of P1 is a 5′-phosphate nucleotide or a 5′-phosphate analogue modified nucleotide.

14. A pharmaceutical composition, wherein the pharmaceutical composition comprises the siRNA according to claim 1 and a pharmaceutically acceptable carrier.

15. A siRNA conjugate, comprising the siRNA according to claim 1 and a conjugating group conjugated to the siRNA.

16. The siRNA conjugate according to claim 15 , wherein the conjugate has a structure as shown by Formula (308):

wherein n1 is an integer of 1-3, and n3 is an integer of 0-4;

m1, m2, and m3 independently of one another are an integer of 2-10;

R 10 , R 11 , R 12 , R 13 , R 14 and R 15 independently of one another are H, or selected from the group consisting of C 1 -C 10 alkyl, C 1 -C 10 haloalkyl, and C 1 -C 10 alkoxy;

R 3 is a group having a structure as shown by Formula (A59):

wherein E1 is OH, SH or BH 2 ; Nu is siRNA;

R 2 is a linear alkylene of 1 to 20 carbon atoms in length, wherein one or more carbon atoms are optionally replaced with one or more groups selected from the group consisting of: C(O), NH, O, S, CH═N, S(O) 2 , C 2 -C 10 alkenylene, C 2 -C 10 alkynylene, C 6 -C 10 arylene, C 3 -C 18 heterocyclylene, and C 5 -C 10 heteroarylene, and wherein R 2 optionally has one or more substituents selected from the group consisting of: C 1 -C 10 alkyl, C 6 -C 10 aryl, C 5 -C 10 heteroaryl, C 1 -C 10 haloalkyl, —OC 1 -C 10 alkyl, —OC 1 -C 10 alkylphenyl, —C 1 -C 10 alkyl-OH, —OC 1 -C 10 haloalkyl, —SC 1 -C 10 alkyl, —SC 1 -C 10 alkylphenyl, —C 1 -C 10 alkyl-SH, —SC 1 -C 10 haloalkyl, halo, —OH, —SH, —NH 2 , —C 1 -C 10 alkyl-NH 2 , —N(C 1 -C 10 alkyl)(C 1 -C 10 alkyl), —NH(C 1 -C 10 alkyl), cyano, nitro, —CO 2 H, —C(O)O(C 1 -C 10 alkyl), —CON(C 1 -C 10 alkyl)(C 1 -C 10 alkyl), —CONH(C 1 -C 10 alkyl), —CONH 2 , —NHC(O)(C 1 -C 10 alkyl), —NHC(O)(phenyl), —N(C 1 -C 10 alkyl)C(O)(C 1 -C 10 alkyl), —N(C 1 -C 10 alkyl)C(O)(phenyl), —C(O)C 1 -C 10 alkyl, —C(O)C 1 -C 10 alkylphenyl, —C(O)C 1 -C 10 haloalkyl, —OC(O)C 1 -C 10 alkyl, —SO 2 (C 1 -C 10 alkyl), —SO 2 (phenyl), —SO 2 (C 1 -C 10 haloalkyl), —SO 2 NH 2 , —SO 2 NH(C 1 -C 10 alkyl), —SO 2 NH(phenyl), —NHSO 2 (C 1 -C 10 alkyl), —NHSO 2 (phenyl), and —NHSO 2 (C 1 -C 10 haloalkyl);

each L1 is independently a linear alkylene of 1 to 70 carbon atoms in length, wherein one or more carbon atoms are optionally replaced with one or more groups selected from the group consisting of: C(O), NH, O, S, CH═N, S(O) 2 , C 2 -C 10 alkenylene, C 2 -C 10 alkynylene, C 6 -C 10 arylene, C 3 -C 18 heterocyclylene, and C 5 -C 10 heteroarylene, and wherein L 1 optionally has one or more substituents selected from the group consisting of: C 1 -C 10 alkyl, C 6 -C 10 aryl, C 5 -C 10 heteroaryl, C 1 -C 10 haloalkyl, —OC 1 -C 10 alkyl, —OC 1 -C 10 alkylphenyl, —C 1 -C 10 alkyl-OH, —OC 1 -C 10 haloalkyl, —SC 1 -C 10 alkyl, —SC 1 -C 10 alkylphenyl, —C 1 -C 10 alkyl-SH, —SC 1 -C 10 haloalkyl, halo, —OH, —SH, —NH 2 , —C 1 -C 10 alkyl-NH 2 , —N(C1-C 10 alkyl)(C 1 -C 10 alkyl), —NH(C 1 -C 10 alkyl), cyano, nitro, —CO 2 H, —C(O)O(C 1 -C 10 alkyl), —CON(C 1 -C 10 alkyl)(C 1 -C 10 alkyl), —CONH(C 1 -C 10 alkyl), —CONH 2 , —NHC(O)(C 1 -C 10 alkyl), —NHC(O)(phenyl), —N(C 1 -C 10 alkyl)C(O)(C 1 -C 10 alkyl), —N(C 1 -C 10 alkyl)C(O)(phenyl), —C(O)C 1 -C 10 alkyl, —C(O)C 1 -C 10 alkylphenyl, —C(O)C 1 -C 10 haloalkyl, —OC(O)C 1 -C 10 alkyl, —SO 2 (C 1 -C 10 alkyl), —SO 2 (phenyl), —SO 2 (C 1 -C 10 haloalkyl), —SO 2 NH 2 , —SO 2 NH(C 1 -C 10 alkyl), —SO 2 NH(phenyl), —NHSO 2 (C 1 -C 10 alkyl), —NHSO 2 (phenyl), and —NHSO 2 (C 1 -C 10 haloalkyl);

represents a site where a group is linked to the rest of the molecule;

M 1 represents a targeting group.

17. The siRNA conjugate according to claim 16 , wherein each L1 is independently selected from the connection combinations of one or more of Formulae A1-A26:

wherein j1 is an integer of 1-20;

j2 is an integer of 1-20;

R′ is a C 1 -C 10 alkyl;

Ra is selected from the group consisting of Formulae A27-A45, and connection combination thereof:

Rb is a C 1 -C 10 alkyl.

18. The siRNA conjugate according to claim 16 , wherein L1 is selected from the connection combinations of one or more of A1, A4, A5, A6, A8, A10, A11, A13, and thereof; or L 1 is selected from the connection combinations of at least two of A1, A4, A8, A10, and A11.

19. The siRNA conjugate according to claim 17 , wherein L 1 is 3 to 25 atoms in length, or the length of L 1 further is 4 to 15 atoms.

20. The siRNA conjugate according to claim 17 , wherein m1, m2 and m3 independently of one another are an integer of 2-5; or wherein m1=m2=m3.

21. The siRNA conjugate according to claim 16 , wherein each of the targeting groups is independently a ligand that has affinity to the asialoglycoprotein receptors (ASGP-R) on the surface of mammalian hepatocytes.

22. The siRNA conjugate according to claim 21 , wherein each of the targeting groups is independently an asialoglycoprotein or saccharide.

23. The siRNA conjugate according to claim 21 , wherein at least one or each of the targeting groups is galactose or N-acetylgalactosamine.

24. The siRNA conjugate according to claim 16 , wherein the conjugate has a structure as shown by Formula (403), (404), (405), (406), (407), (408), (409), (410), (411), (412), (413), (414), (415), (416), (417), (418), (419), (420), (421), or (422):

25. The siRNA conjugate according to claim 16 , wherein the P atom in Formula A59 is linked to 3′ terminal of the sense strand of the siRNA.

26. A method for treating and/or preventing a pathological condition or disease caused by HBV infection, wherein the method comprises administering to a subject in need thereof an effective amount of the siRNA according to claim 1 and/or the siRNA conjugate comprising the same.