Wnt signaling inhibitor

1. A fused-ring heterocyclic compound represented by formula (I) or a pharmaceutically acceptable salt thereof:

wherein:

n 1 represents 0 or 1;

n 2 and n 3 may be the same or different, and each represents 1 or 2;

when n 1 is 0, R 1 represents an optionally substituted aryl, an optionally substituted aromatic heterocyclic group, or an optionally substituted aliphatic heterocyclic group, and when n 1 is 1, R 1 represents an aryl substituted with cyano or carbamoyl, an optionally substituted aromatic heterocyclic group, or an optionally substituted aliphatic heterocyclic group;

R 2 represents a hydrogen atom or hydroxy;

R 3 represents an optionally substituted aromatic heterocyclic group or an optionally substituted aliphatic heterocyclic group;

X 1 , X 2 , X 3 , and X 4 may be the same or different, and each represents N or CR 4 ;

each R 4 independently represents a hydrogen atom, a lower alkyl, cyano, a halogen, hydroxy, a lower alkoxy, a lower alkanoyl, or a lower alkylsulfonyl;

Y 1 represents CH 2 or C(═O);

Y 2 represents CH or N; and

L represents CH 2 or NH.

2. The compound or pharmaceutically acceptable salt according to claim 1 , wherein n 2 and n 3 are each 2.

3. The compound or pharmaceutically acceptable salt according to claim 1 , wherein Y 2 is N, and L is CH 2 .

4. The compound or pharmaceutically acceptable salt according to claim 1 , wherein Y 1 is CH 2 .

5. The compound or pharmaceutically acceptable salt according to claim 1 , wherein n 1 is 0.

6. The compound or pharmaceutically acceptable salt according to claim 1 , wherein:

when n 1 is 0, R 1 is (i) an optionally substituted phenyl, or (ii) an optionally substituted pyridyl, pyridonyl, or pyrimidinyl; and

when n 1 is 1, R 1 is (i) a phenyl substituted with cyano or carbamoyl, or (ii) an optionally substituted pyridyl, pyridonyl, or pyrimidinyl.

7. The compound or pharmaceutically acceptable salt according to claim 1 , wherein R 1 is:

a group represented by formula (a1):

wherein

when n 1 is 0:

R 5 represents a hydrogen atom, a C 1-10 alkyl which may be substituted with hydroxy, a C 1-10 alkoxycarbonyl, a C 2-11 alkanoyl, a C 1-10 alkylsulfonyl, a —NR 6a R 6b wherein R 6a and R 6b may be the same or different, and each represents a hydrogen atom, a C 2-11 alkanoyl, or a C 1-10 alkyl, —CONR 6c R 6d wherein R 6c and R 6d may be the same or different, and each represents a hydrogen atom or a C 1-10 alkyl, —SO 2 NR 6e R 6f wherein R 6e and R 6f may be the same or different, and each represents a hydrogen atom or a C 1-10 alkyl, a halogen, cyano, carboxy, or nitro; and

Z 1 , Z 2 , Z 3 , and Z 4 may be the same or different, and each represents N or CR 7 wherein R 7 represents a hydrogen atom, carboxy, or a halogen; or

when n 1 is 1:

R 5 represents a carbamoyl or cyano; and

Z 1 , Z 2 , Z 3 , and Z 4 may be the same or different, and each represents N or CR 7 wherein R 7 represents a hydrogen atom; or

a group represented by the following formula (a2):

wherein R 5 , Z 1 , and Z 4 are as defined above when n 1 is 0 and 1, respectively.

8. The compound or pharmaceutically acceptable salt according to claim 7 , wherein:

when n 1 is 0, R 5 is cyano, —CONH 2 , or —SO 2 NH 2 ; and

when n 1 is 1 R 5 is cyano or —CONH 2 .

9. The compound or pharmaceutically acceptable salt according to claim 7 , wherein R 5 is cyano.

10. The compound or pharmaceutically acceptable salt according to claim 7 , wherein:

when n 1 is 0, R 7 is a hydrogen atom or a fluorine atom; and

when n 1 is 1, R 7 is a hydrogen atom.

11. The compound or pharmaceutically acceptable salt according to claim 1 , wherein R 3 is an optionally substituted aromatic heterocyclic group.

12. The compound or pharmaceutically acceptable salt according to claim 11 , wherein the aromatic heterocyclic group is a bicyclic aromatic heterocyclic group.

13. The compound or pharmaceutically acceptable salt according to claim 11 , wherein the aromatic heterocyclic group is quinazolinyl.

14. The compound or pharmaceutically acceptable salt according to claim 1 , wherein R 3 is an optionally substituted aliphatic heterocyclic group.

15. A pharmaceutical composition, comprising, as an active ingredient, the compound or pharmaceutically acceptable salt according to claim 1 .