Antibody being capable of binding to transforming growth factor alpha and having growth-suppressing activity on cancers having Ras gene mutation
It has been found out that among antibodies showing reactivity with wild type TGF-α, antibodies less reactive with G79A-substituted TGF-α have an excellent growth-suppressing effect on cancer cells having a mutated Ras gene. Further, it has been found out that most of these antibodies have an activity of inhibiting EGFR tyrosine phosphorylation and/or an induction-suppressing activity on vascular endothelial cells.
1. An antibody that specifically binds to human TGF-α, wherein the antibody comprises any one of the following characteristics (a) to (h):
(a) a light chain variable region including the amino acid sequences of SEQ ID NOs: 19 to 21, and
a heavy chain variable region including the amino acid sequences of SEQ ID NOs: 22 to 24;
(b) a light chain variable region including the amino acid sequences of SEQ ID NOs: 25 to 27, and
a heavy chain variable region including the amino acid sequences of SEQ ID NOs: 28 to 30;
(c) a light chain variable region including the amino acid sequences of SEQ ID NOs: 31 to 33, and
a heavy chain variable region including the amino acid sequences of SEQ ID NOs: 34 to 36;
(d) a light chain variable region including the amino acid sequences of SEQ ID NOs: 37 to 39, and
a heavy chain variable region including the amino acid sequences of SEQ ID NOs: 40 to 42;
(e) a light chain variable region including the amino acid sequences of SEQ ID NOs: 43 to 45, and
a heavy chain variable region including the amino acid sequences of SEQ ID NOs: 46 to 48;
(f) a light chain variable region including the amino acid sequences of SEQ ID NOs: 49 to 51, and
a heavy chain variable region including the amino acid sequences of SEQ ID NOs: 52 to 54;
(g) a light chain variable region including the amino acid sequences of SEQ ID NOs: 55 to 57, and
a heavy chain variable region including the amino acid sequences of SEQ ID NOs: 58 to 60; and
(h) a light chain variable region including the amino acid sequences of SEQ ID NOs: 61 to 63, and
a heavy chain variable region including the amino acid sequences of SEQ ID NOs: 64 to 66.
2. The antibody according to claim 1 having a growth-suppressing activity on cancer cells having a mutated Ras gene.
3. The antibody according to claim 1 , wherein the antibody binds human TGF-α having a mutated glycine at a position corresponding to position 79 of SEQ ID NO:2 with lower affinity than to wild type human TGF-α.
4. The antibody according to claim 3 , wherein the human TGF-α having the mutated glycine at a position corresponding to position 79 of SEQ ID NO:2 is a G 79 A-substituted human TGF-α.
5. The antibody according to claim 1 , which has an activity of suppressing EGFR tyrosine phosphorylation.
6. The antibody according to claim 1 , which has an activity of suppressing induction of vascular endothelial cells.
7. A DNA encoding the antibody according to claim 1 .
8. A hybridoma comprising the DNA according to claim 7 .
9. An expression vector comprising the DNA of claim 7 .
10. A host cell transformed with the expression vector of claim 9 .
11. A method of producing an antibody, comprising culturing the host cell of claim 10 , and purifying the antibody expressed by the expression vector.
12. A hybridoma producing the antibody according to claim 1 .
13. A composition comprising the antibody according to claim 1 , and a pharmaceutically acceptable carrier.
14. An antibody that specifically binds to human TGF-α, wherein the antibody comprises any one of the following characteristics (a) to (h):
(a) a light chain variable region including the amino acid sequence of SEQ ID NO: 3, and
a heavy chain variable region including the amino acid sequence of SEQ ID NO: 4;
(b) a light chain variable region including the amino acid sequence of SEQ ID NO: 5, and
a heavy chain variable region including the amino acid sequence of SEQ ID NO: 6;
(c) a light chain variable region including the amino acid sequence of SEQ ID NO: 7, and
a heavy chain variable region including the amino acid sequence of SEQ ID NO: 8;
(d) a light chain variable region including the amino acid sequence of SEQ ID NO: 9, and
a heavy chain variable region including the amino acid sequence of SEQ ID NO: 10;
(e) a light chain variable region including the amino acid sequence of SEQ ID NO: 11, and
a heavy chain variable region including the amino acid sequence of SEQ ID NO: 12;
(f) a light chain variable region including the amino acid sequence of SEQ ID NO: 13, and
a heavy chain variable region including the amino acid sequence of SEQ ID NO: 14;
(g) a light chain variable region including the amino acid sequence of SEQ ID NO: 15, and
a heavy chain variable region including the amino acid sequence of SEQ ID NO: 16; and
(h) a light chain variable region including the amino acid sequence of SEQ ID NO: 17, and
a heavy chain variable region including the amino acid sequence of SEQ ID NO: 18.
15. A DNA encoding the antibody according to claim 14 .
16. An expression vector comprising the DNA of claim 15 .
17. A host cell transformed with the expression vector of claim 16 .
18. A method of producing an antibody, comprising culturing the host cell of claim 17 , and purifying the antibody expressed by the expression vector.
19. An antibody produced by a hybridoma specified under an accession number of FERM ABP-11377.