Chimeric adenoviruses for use in cancer treatment

1. A chimeric oncolytic adenovirus which has a genome comprising a chimeric E2B region, wherein:

said chimeric E2B region comprises a nucleic acid sequence comprising a first nucleic acid sequence from a first adenoviral serotype and a second nucleic acid sequence from a second adenoviral serotype, wherein the nucleic acid sequence of said chimeric E2B region of said adenovirus has at least 98% sequence identity to SEQ ID NO:3; and

said first and second serotypes are each selected from the adenoviral subgroups B, C, D, E, or F and are distinct from each other.

2. The chimeric oncolytic adenovirus of claim 1 wherein the first adenoviral serotype is selected from subgroup B.

3. The chimeric oncolytic adenovirus of claim 1 wherein the first and second adenoviral serotypes are selected from subgroup B.

4. The chimeric oncolytic adenovirus of claim 3 wherein one of the adenoviral serotypes is Ad11.

5. The chimeric oncolytic adenovirus of claim 3 wherein the first adenoviral serotype is Ad11 and the second adenoviral serotype is Ad3.

6. The chimeric oncolytic adenovirus of claim 1 having regions encoding a fibre, hexon and penton proteins wherein the nucleic acids encoding fibre, hexon and penton proteins are all from the same adenovirus serotype.

7. The chimeric oncolytic adenovirus of claim 6 wherein the nucleic acids encoding fibre, hexon and penton proteins are all from Ad11.

8. The chimeric oncolytic adenovirus of claim 1 , further comprising a modified E3 region.

9. The chimeric oncolytic adenovirus of claim 1 , further comprising a modified E4 region.

10. The chimeric oncolytic adenovirus of claim 1 , which is oncolytic against a tumor cell selected from the group consisting of a colon tumor cell, a breast tumor cell, a pancreas tumor cell, a lung tumor cell, a prostate tumor cell, an ovarian tumor cell, and a hematopoietic tumor cell.

11. The chimeric oncolytic adenovirus of claim 10 , wherein the tumor cell is a colon tumor cell.

12. The chimeric oncolytic adenovirus of claim 1 which has been rendered replication deficient through deletion of one or more adenoviral regions encoding proteins involved in adenoviral replication selected from the group consisting of E1, E2, E3, or E4.

13. The chimeric oncolytic adenovirus of claim 12 , wherein the E1 and E3 regions have been deleted.

14. The chimeric oncolytic adenovirus of claim 13 , further comprising a deletion of the E4 region.

15. The chimeric oncolytic adenovirus of claim 1 , further comprising a heterologous gene, wherein said heterologous gene is expressed within a cell infected with said adenovirus.

16. The chimeric oncolytic adenovirus of claim 15 , wherein said heterologous gene is thymidine kinase.

17. The chimeric oncolytic adenovirus of claim 15 , wherein said heterologous gene encodes a therapeutic protein selected from the group consisting of cytokines, chemokines, antibodies, pro-drug converting enzymes, and immunoregulatory proteins.

18. The chimeric oncolytic adenovirus of claim 12 , further comprising a heterologous gene, wherein said heterologous gene is expressed within a cell infected with said adenovirus.

19. The chimeric oncolytic adenovirus of claim 18 , wherein said heterologous gene is thymidine kinase.

20. The chimeric adenovirus of claim 18 , wherein said heterologous gene encodes a therapeutic protein selected from the group consisting of cytokines, chemokines, antibodies, pro-drug converting enzymes, and immunoregulatory proteins.

21. The chimeric oncolytic adenovirus of claim 1 , which has been rendered replication deficient through deletion of the E1 region.

22. The chimeric oncolytic adenovirus of claim 2 , which has been rendered replication deficient through deletion of the E1 region.

23. The chimeric oncolytic adenovirus of claim 3 , which has been rendered replication deficient through deletion of the E1 region.

24. The chimeric oncolytic adenovirus of claim 1 wherein the nucleotide sequence of said chimeric E2B region of said adenovirus has at least 99% sequence identity to SEQ ID NO:3.

25. The chimeric oncolytic adenovirus of claim 1 which demonstrates an enhanced therapeutic index for a tumor cell relative to an Ad5 adenovirus.

26. A method for inhibiting growth of a cancer cell, comprising infecting said cancer cell with a chimeric oncolytic adenovirus which has a genome comprising a chimeric E2B region, wherein:

said chimeric E2B region comprises a nucleic acid sequence comprising a first nucleic acid sequence from a first adenoviral serotype and a second nucleic acid sequence from a second adenoviral serotype, wherein the nucleotide sequence of said E2B region of said adenovirus has at least 98% sequence identity to SEQ ID NO:3;

said first and second serotypes are each selected from the adenoviral subgroups B, C, D, E, or F and are distinct from each other.

27. The method of claim 26 , wherein said cancer cell is a colon cancer cell.

28. The method of claim 26 , wherein the chimeric oncolytic adenovirus further comprises regions encoding fiber, hexon, and penton proteins, wherein the nucleic acid encoding the fiber, hexon, and penton proteins of the adenovirus are from the same adenoviral serotype.

29. The method of claim 28 , wherein the nucleic acids encoding fibre, hexon and penton proteins are all from Ad11.

30. The method of claim 26 , wherein the cancer cell is a colon, breast, pancreas, lung, prostate, ovarian, or hematopoietic cancer cell.

31. The method of claim 26 , wherein the first adenoviral serotype is selected from subgroup B.

32. The method of claim 26 , wherein the first and second adenoviral serotypes are selected from subgroup B.

33. The method of claim 26 , wherein one of the adenoviral serotypes is Ad11.

34. The method of claim 26 , wherein the first adenoviral serotype is Ad11 and the second adenoviral serotype is Ad3.