Promoters exhibiting endothelial cell specificity and methods of using same for regulation of angiogenesis

• US 20050186179A1
• Filed: 11/14/2004
• Published: 08/25/2005
• Est. Priority Date: 11/17/2000
• Status: Active Grant

• Current Assignee: Vascular Biogenics Ltd.
• Original Assignee: Vascular Biogenics Ltd.
• Inventors: Greenberger, Shoshana, Harats, Dror
• Granted Patent: US 8,071,740 B2
• Time in Patent Office: Days
• US Class Current: 424/93.200
• CPC Class Codes: A61K 38/00 Medicinal preparations containing peptides peptides containing beta-lactam rings A61K31/00; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, A61K31/00; ergot alkaloids of the cyclic peptide type A61K31/48; containing macromolecular compounds having statistically distributed amino acid units A61K31/74; medicinal preparations containing antigens or antibodies A61K39/00; medicinal preparations characterised by the non-active ingredients, e.g. peptides as drug carriers, A61K47/00
• CPC Class Codes: A61K 48/00 Medicinal preparations containing genetic material which is inserted into cells of the living body to treat genetic diseases; Gene therapy
• CPC Class Codes: A61K 48/0008 characterised by an aspect of the 'non-active' part of the composition delivered, e.g. wherein such 'non-active' part is not delivered simultaneously with the 'active' part of the composition
• CPC Class Codes: A61K 48/0058 Nucleic acids adapted for tissue specific expression, e.g. having tissue specific promoters as part of a contruct
• CPC Class Codes: A61P 17/06 Antipsoriatics
• CPC Class Codes: A61P 19/02 for joint disorders, e.g. arthritis, arthrosis
• CPC Class Codes: A61P 27/02 Ophthalmic agents
• CPC Class Codes: A61P 35/00 Antineoplastic agents
• CPC Class Codes: A61P 35/04 specific for metastasis
• CPC Class Codes: A61P 43/00 Drugs for specific purposes, not provided for in groups A61P1/00-A61P41/00
• CPC Class Codes: A61P 9/00 Drugs for disorders of the cardiovascular system
• CPC Class Codes: A61P 9/10 for treating ischaemic or atherosclerotic diseases, e.g. antianginal drugs, coronary vasodilators, drugs for myocardial infarction, retinopathy, cerebrovascula insufficiency, renal arteriosclerosis
• CPC Class Codes: A61P 9/14 Vasoprotectives; Antihaemorrhoidals; Drugs for varicose therapy; Capillary stabilisers
• CPC Class Codes: C07K 14/475 Growth factors; Growth regulators
• CPC Class Codes: C07K 14/49 Platelet-derived growth factor [PDGF]
• CPC Class Codes: C07K 14/503 basic FGF [bFGF]
• CPC Class Codes: C07K 14/515 Angiogenesic factors; Angiogenin
• CPC Class Codes: C07K 14/52 Cytokines; Lymphokines; Interferons
• CPC Class Codes: C07K 14/57536 Endothelin, vasoactive intestinal contractor [VIC]
• CPC Class Codes: C07K 14/70578 NGF-receptor/TNF-receptor superfamily, e.g. CD27, CD30, CD40, CD95 NGF-receptor C07K14/71, TNF-receptor C07K14/7151
• CPC Class Codes: C07K 2319/70 : containing domain for protein-protein interaction
• CPC Class Codes: C12N 15/85 : for animal cells
• CPC Class Codes: C12N 15/86 : Viral vectors
• CPC Class Codes: C12N 2710/10343 : viral genome or elements thereof as genetic vector
• CPC Class Codes: C12N 2800/108 : episomal vectors
• CPC Class Codes: C12N 2830/002 : inducible enhancer/promoter combination, e.g. hypoxia, iron, transcription factor
• CPC Class Codes: C12N 2830/008 : cell type or tissue specific enhancer/promoter combination
• CPC Class Codes: C12N 2830/15 : chimeric enhancer/promoter combination
• CPC Class Codes: C12N 2830/30 : being an enhancer not forming part of the promoter region
• CPC Class Codes: C12N 2830/85 : mammalian
• CPC Class Codes: C12N 2840/20 : translation of more than one cistron
• CPC Class Codes: C12N 2840/203 : having an IRES

Abstract

Isolated polynucleotide sequences exhibiting endothelial cell specific promoter activity, novel cis regulatory elements and methods of use thereof enabling treatment of diseases characterized by aberrant neovascularization or cell growth are disclosed.

Claims

1. An isolated polynucleotide comprising a cis regulatory element including at least a portion of the sequence set forth in SEQ ID NO:

15 covalently linked to at least a portion of the sequence set forth in SEQ ID NO;

16, the isolated polynucleotide being capable of directing transcription of a polynucleotide sequence transcriptionally linked thereto in eukaryotic cells.

2. The isolated polynucleotide of claim 1, wherein said at least a portion of the sequence set forth in SEQ ID NO:

15 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

16 in said cis regulatory element.

3. The isolated polynucleotide of claim 1, wherein said at least a portion of the sequence set forth in SEQ ID NO:

16 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

15 in said cis regulatory element.

4. The isolated polynucleotide of claim 1, wherein said cis regulatory element further includes at least one copy of the sequence set forth in SEQ ID NO:

6.

5. The isolated polynucleotide of claim 1, wherein said at least a portion of the sequence set forth in SEQ ID NO:

15 is covalently linked to said at least a portion of the sequence set forth in SEQ ID NO;

16 via a linker polynucleotide sequence.

6. The isolated polynucleotide of claim 1, wherein said linker polynucleotide sequence is a promoter and/or an enhancer element.

7. The isolated polynucleotide of claim 1, wherein said cis regulatory element further includes at least two copies of the sequence set forth in SEQ ID NO:

6.

8. The isolated polynucleotide of claim 1, further comprising at least one copy of the sequence set forth in SEQ ID NO:

1.

9. The isolated polynucleotide of claim 1, further comprising a hypoxia response element.

10. The isolated polynucleotide of claim 9, wherein said hypoxia response element includes at least one copy of the sequence set forth in SEQ ID NO:

5.

11. The isolated polynucleotide of claim 1, wherein said cis regulatory element is as set forth in SEQ ID NO:

7.

12. A nucleic acid construct comprising the isolated polynucleotide of claim 1.

13. The nucleic acid construct of claim 12, further comprising a nucleic acid sequence positioned under the regulatory control of said cis regulatory element.

14. The nucleic acid construct of claim 13, wherein said nucleic acid sequence encodes an angiogenesis regulator.

15. The nucleic acid construct of claim 10, wherein said nucleic acid sequence is selected from the group consisting of VEGF, p55, angiopoietin-1, bFGF and PDGF-BB.

16. The nucleic acid construct of claim 1, further comprising a conditionally replicating adenovirus.

17. A cell comprising the nucleic acid construct of claim 12.

18. A scaffold seeded with the cell of claim 17.

19. The scaffold of claim 18, wherein the scaffold is composed of a synthetic polymer, a cell adhesion molecule, or an extracellular matrix protein.

20. The scaffold of claim 19, wherein said synthetic polymer is selected from the group consisting of polyethylene glycol (PEG), Hydroxyapatite (HA), polyglycolic acid (PGA), epsilon-caprolactone and 1-lactic acid reinforced with a poly-1-lactide knitted [KN-PCLA], woven fabric (WV-PCLA), interconnected-porous calcium hydroxyapatite ceramics (IP-CHA), poly D,L,-lactic acid-polyethyleneglycol (PLA-PEG), unsaturated polyester poly(propylene glycol-co-funaric acid) (PPF), polylactide-co-glycolide (PLAGA), polyhydroxyalkanoate (PHA), poly-4-hydroxybutyrate (P4HB), and polyphosphazene.

21. The scaffold of claim 19, wherein said cell adhesion molecule is selected from the group consisting of integrin, intercellular adhesion molecule (ICAM) 1, N-CAM, cadherin, tenascin, gicerin, and nerve injury induced protein 2 (ninjurin2).

22. The method of claim 19, wherein said extracellular matrix protein is selected from the group consisting of fibrinogen, Collagen, fibronectin, vimentin, microtubule-associated protein ID, Neurite outgrowth factor (NOF), bacterial cellulose (BC), laminin and gelatin.

23. A method of expressing a nucleic acid sequence of interest in eukaryotic cells, the method comprising administering to a subject a nucleic acid construct including the nucleic acid sequence of interest positioned under transcriptional control of a cis regulatory element including at least a portion of the sequence set forth in SEQ ID NO:

15 covalently linked to at least a portion of the sequence set forth in SEQ ID NO;

16.

24. The method of claim 23, wherein said at least a portion of the sequence set forth in SEQ ID NO:

15 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

16 in said cis regulatory element.

25. The method of claim 23, wherein said at least a portion of the sequence set forth in SEQ ID NO:

16 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

15 in said cis regulatory element.

26. The method of claim 23, wherein said cis regulatory element further includes at least one copy of the sequence set forth in SEQ ID NO:

6.

27. The method of claim 23, wherein said at least a portion of the sequence set forth in SEQ ID NO:

15 is covalently linked to said at least a portion of the sequence set forth in SEQ ID NO;

16 via a linker polynucleotide sequence.

28. The method of claim 27, wherein said linker polynucleotide sequence is a promoter and/or an enhancer element.

29. The method of claim 23, wherein said cis regulatory element further includes at least two copies of the sequence set forth in SEQ ID NO:

6.

30. The method of claim 23, wherein said cis regulatory element further comprises at least one copy of the sequence as set forth in SEQ ID NO:

1.

31. The method of claim 23, wherein said cis regulatory element further comprises a hypoxia response element.

32. The method of claim 31, wherein said hypoxia response element includes at least one copy of the sequence set forth in SEQ ID NO:

5.

33. The method of claim 23, wherein said cis regulatory element is as set forth in SEQ ID NO:

7.

34. The method of claim 29, wherein said at least two copies of the sequence set forth in SEQ ID NO:

6 are contiguous.

35. The method of claim 23, wherein said nucleic acid sequence of interest is selected from the group consisting of a nucleic acid encoding a cytotoxic factor, an angiogenic factor, a reporter protein, a growth factor and a pro-apoptotic factor.

36. The method of claim 23, wherein said nucleic acid construct further comprises a conditionally replicating adenovirus.

37. The method of claim 23, wherein administering is effected by a method selected from the group consisting of:

(i) systemic in-vivo administration;

(ii) ex-vivo administration to cells removed from a body of a subject and subsequent reintroduction of said cells into said body of said subject; and

(iii) local in-vivo administration.

38. A method of regulating angiogenesis in a tissue, the method comprising expressing in the tissue a nucleic acid construct including:

(a) an endothelial cell specific promoter;

(b) at least one copy of a hypoxia response element set forth in SEQ ID NO;

5; and

(c) a nucleic acid sequence encoding an angiogenesis regulator, said nucleic acid sequence being under regulatory control of said promoter and said hypoxia response element.

39. The method of claim 38, wherein said tissue is a natural tissue or an engineered tissue.

40. The method of claim 38, further comprising the step of administering to the tissue said nucleic acid construct by a method selected from the group consisting of:

(i) systemic in-vivo administration;

(ii) ex-vivo administration to cells removed from a body of a subject, said cells subsequently reintroduced into said body of said subject; and

(iii) local in-vivo administration.

41. The method of claim 38, wherein said endothelial cell promoter further includes:

(d) at least a portion of the sequence set forth in SEQ ID NO;

15 covalently linked to at least a portion of the sequence set forth in SEQ ID NO;

16.

42. The method of claim 41, wherein said endothelial cell promoter includes at least one copy of a sequence as set forth in SEQ ID NO:

7.

43. The method of claim 41, wherein said nucleic acid construct further includes;

(e) at least one copy of a sequence set forth in SEQ ID NO;

6.

44. The method of claim 43, wherein said at least one copy of a sequence set forth in SEQ ID NO:

6 includes two contiguous copies.

45. The method of claim 38, wherein said endothelial cell specific promoter comprises at least one copy of a sequence as set forth in SEQ ID NO:

1.

46. The method of claim 38, wherein said nucleic acid sequence encoding an angiogenesis regulator is selected from the group consisting of VEGF, p55, angiopoietin-1, bFGF and PDGF-BB.

47. The method of claim 38, wherein said nucleic acid construct further comprises a conditionally replicating adenovirus.

48. A method of regulating angiogenesis in a tissue, the method comprising expressing in the tissue a nucleic acid construct including:

a nucleic acid sequence encoding an angiogenesis regulator, said nucleic acid sequence being under regulatory control of a cis regulatory element including at least a portion of the sequence set forth in SEQ ID NO;

15 covalently linked to at least a portion of the sequence set forth in SEQ ID NO;

16, thereby regulating angiogenesis in the tissue.

49. The method of claim 48, wherein said at least a portion of the sequence set forth in SEQ ID NO:

15 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

16 in said cis regulatory element.

50. The method of claim 48, wherein said at least a portion of the sequence set forth in SEQ ID NO:

16 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

15 in said cis regulatory element.

51. The method of claim 48, wherein said cis regulatory element further includes at least one copy of the sequence set forth in SEQ ID NO:

6.

52. The method of claim 50, wherein said at least a portion of the sequence set forth in SEQ ID NO:

15 is covalently linked to said at least a portion of the sequence set forth in SEQ ID NO;

16 via a linker polynucleotide sequence.

53. The method of claim 52, wherein said linker polynucleotide sequence is a promoter and/or an enhancer element.

54. The method of claim 51, wherein said cis regulatory element further includes at least two copies of the sequence set forth in SEQ ID NO:

6.

55. The method of claim 48, wherein said cis regulatory element further comprises at least one copy of the sequence as set forth in SEQ ID NO:

1.

56. The method of claim 48, wherein said cis regulatory element further comprises a hypoxia response element.

57. The method of claim 56, wherein said hypoxia response element includes at least one copy of the sequence set forth in SEQ ID NO:

5.

58. The method of claim 48, wherein said cis regulatory element is as set forth in SEQ ID NO:

7.

59. The method of claim 54, wherein said at least two copies of the sequence set forth in SEQ ID NO:

6 are contiguous.

60. The method of claim 48, wherein said nucleic acid construct further comprises a conditionally replicating adenovirus.

61. The method of claim 48, wherein said nucleic acid sequence encodes a proangiogenic factor and wherein said regulating angiogenesis is upregulating angiogenesis.

62. The method of claim 48, wherein said nucleic acid sequence encodes a proangiogenic factor and wherein said regulating angiogenesis is downregulating angiogenesis.

63. The method of claim 48, further comprising the step of administering to the tissue said nucleic acid construct by a method selected from the group consisting of:

(i) systemic in-vivo administration;

(ii) ex-vivo administration to cells removed from a body of a subject, said cells subsequently reintroduced into said body of said subject; and

(iii) local in-vivo administration.

64. A nucleic acid construct comprising:

(a) a first polynucleotide region encoding a chimeric polypeptide including a ligand binding domain fused to an effector domain of a cytotoxic molecule; and

(b) a second polynucleotide region encoding a cis regulatory element being capable of directing expression of said chimeric polypeptide in a specific tissue or cell;

wherein said ligand binding domain is selected such that it is capable of binding a ligand present in said specific tissue or cell, whereas binding of said ligand to said ligand binding domain activates said effector domain of said cytotoxic molecule.

65. The nucleic acid construct of claim 64, wherein said cis regulatory element includes at least a portion of the sequence set forth in SEQ ID NO:

15 covalently linked to at least a portion of the sequence set forth in SEQ ID NO;

16, the isolated polynucleotide being capable of directing transcription of a polynucleotide sequence transcriptionally linked thereto in eukaryotic cells.

66. The nucleic acid construct of claim 64, wherein said cis regulatory element is an endothelial cell-specific or periendothelial cell-specific promoter selected from the group consisting of the PPE-1 promoter, the PPE-1-3×

promoter, the TIE-1 promoter, the TIE-2 promoter, the Endoglin promoter, the von Willebrand promoter, the KDR/flk-1 promoter, The FLT-1 promoter, the Egr-1 promoter, the ICAM-1 promoter, the VCAM-1 promoter, the PECAM-1 promoter and the aortic carboxypeptidase-like protein (ACLP) promoter.

67. The nucleic acid construct of claim 64, wherein said ligand binding domain is a ligand-binding domain of a cell-surface receptor.

68. The nucleic acid construct of claim 67, wherein said cell-surface receptor is selected from the group consisting of a receptor tyrosine kinase, a receptor serine kinase, a receptor threonine kinase, a cell adhesion molecule and a phosphatase receptor.

69. The nucleic acid construct of claim 64, wherein said cytotoxic molecule is selected from the group consisting of Fas, TNFR, and TRAIL.

70. The nucleic acid construct of claim 64, further comprising a conditionally replicating adenovirus.

71. A eukaryotic cell transformed with the nucleic acid construct of claim 64.

72. The nucleic acid construct of claim 65, wherein said at least a portion of the sequence set forth in SEQ ID NO:

15 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

16 in said cis regulatory element.

73. The nucleic acid construct of claim 65, wherein said at least a portion of the sequence set forth in SEQ ID NO:

16 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

15 in said cis regulatory element.

74. The nucleic acid construct of claim 64, wherein said cis regulatory element further includes at least one copy of the sequence set forth in SEQ ID NO:

6.

75. The nucleic acid construct of claim 65, wherein said at least a portion of said sequences are covalently linked via a linker polynucleotide sequence.

76. The nucleic acid construct of claim 64, further comprising a hypoxia response element.

77. The nucleic acid construct of claim 76, wherein said hypoxia response element includes at least one copy of the sequence set forth in SEQ ID NO:

5.

78. The nucleic acid construct of claim 64, wherein said cis regulatory element is as set forth in SEQ ID NO:

7.

90. The method of claim 74, wherein said cytotoxic molecule is selected from the group consisting of Fas, TNFR and TRAIL.

91. The method of claim 78, wherein said nucleic acid construct further comprises a conditionally replicating adenovirus.

79. A method of downregulating angiogenesis in a tissue of a subject, the method comprising administering to the subject a nucleic acid construct designed and configured for generating cytotoxicity in a sub-population of angiogenic cells, said nucleic acid construct including:

(a) a first polynucleotide region encoding a chimeric polypeptide including a ligand binding domain fused to an effector domain of a cytotoxic molecule; and

(b) a second polynucleotide region encoding a cis regulatory element being for directing expression of said chimeric polypeptide in said sub-population of angiogenic cells;

wherein said ligand binding domain is selected such that it is capable of binding a ligand present in, or provided to, said sub-population of angiogenic cells, whereas binding of said ligand to said ligand binding domain activates said effector domain of said cytotoxic molecule, thereby down-regulating angiogenesis in the tissue.

80. The method of claim 79, wherein said cis regulatory element includes at least a portion of the sequence set forth in SEQ ID NO:

15 covalently linked to at least a portion of the sequence set forth in SEQ ID NO;

16, the isolated polynucleotide being capable of directing transcription of a polynucleotide sequence transcriptionally linked thereto in eukaryotic cells.

81. The method of claim 80, wherein said at least a portion of the sequence set forth in SEQ ID NO:

15 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

16 in said cis regulatory element.

82. The method of claim 80, wherein said at least a portion of the sequence set forth in SEQ ID NO:

16 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

15 in said cis regulatory element.

83. The method of claim 79, further comprising administering said ligand to the subject in a manner suitable for providing said ligand to said sub-population of angiogenic cells.

84. The method of claim 79, further comprising administering to said subject, in combination therewith, at least one additional therapeutic modality, said additional therapeutic modality selected capable of further potentiating said cytotoxicity in a synergic manner.

85. The method of claim 84, wherein said at least one additional therapeutic modality is selected from the group comprising chemotherapy, radiotherapy, phototherapy and photodynamic therapy, surgery, nutritional therapy, ablative therapy, combined radiotherapy and chemotherapy, brachiotherapy, proton beam therapy, immunotherapy, cellular therapy and photon beam radiosurgical therapy.

86. The method of claim 79, wherein said administering said ligand to the subject is effected by a method selected from the group consisting of:

(i) systemic in-vivo administration;

(ii) ex-vivo administration to cells removed from a body of the subject, said cells subsequently reintroduced into said body of the subject; and

(iii) local in-vivo administration.

87. The method of claim 79, wherein said cis regulatory element is an endothelial cell-specific or periendothelial cell-specific promoter selected from the group consisting of the PPE-1 promoter, the PPE-1-3×

promoter, the TIE-1 promoter, the TIE-2 promoter, the Endoglin promoter, the von Willebrand promoter, the KDR/flk-1 promoter, The FLT-1 promoter, the Egr-1 promoter, the ICAM-1 promoter, the VCAM-1 promoter, the PECAM-1 promoter and the aortic carboxypeptidase-like protein (ACLP) promoter.

88. The method of claim 79, wherein said ligand binding domain is a ligand-binding domain of a cell-surface receptor.

89. The method of claim 88, wherein said cell-surface receptor is selected from the group consisting of a receptor tyrosine kinase, a receptor serine kinase, a receptor threonine kinase, a cell adhesion molecule and a phosphatase receptor.

92. A method of down-regulating angiogenesis in a tissue of a subject, the method comprising:

(a) expressing in the tissue of the subject a nucleic acid construct designed and configured for generating cytotoxicity in a sub-population of angiogenic cells, said nucleic acid construct including;

(i) a first polynucleotide region encoding a chimeric polypeptide including a ligand binding domain fused to an effector domain of a cytotoxic molecule, wherein said effector domain is selected such that it is activated following binding of a ligand to said ligand binding domain; and

(ii) a second polynucleotide region encoding a cis acting regulatory element being for directing expression of said chimeric polypeptide in said sub-population of angiogenic cells; and

(b) administering to the subject said ligand, thereby down-regulating angiogenesis in the tissue.

93. The method of claim 92, wherein said cis regulatory element includes at least a portion of the sequence set forth in SEQ ID NO:

15 covalently linked to at least a portion of the sequence set forth in SEQ ID NO;

16, the isolated polynucleotide being capable of directing transcription of a polynucleotide sequence transcriptionally linked thereto in eukaryotic cells.

95. The method of claim 93, wherein said at least a portion of the sequence set forth in SEQ ID NO:

16 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

15 in said cis regulatory element.

96. The method of claim 92, wherein said administering said ligand to the subject is effected by a method selected from the group consisting of:

(i) systemic in-vivo administration;

(ii) ex-vivo administration to cells removed from a body of the subject, said cells subsequently reintroduced into said body of the subject; and

(iii) local in-vivo administration.

97. The method of claim 92, further comprising administering to said subject, in combination therewith, at least one additional therapeutic modality, said additional therapeutic modality selected capable of further potentiating said cytotoxicity in a synergic manner.

98. The method of claim 97, wherein said at least one additional therapeutic modality is selected from the group comprising chemotherapy, radiotherapy, phototherapy and photodynamic therapy, surgery, nutritional therapy, ablative therapy, combined radiotherapy and chemotherapy, brachiotherapy, proton beam therapy, immunotherapy, cellular therapy and photon beam radiosurgical therapy.

99. The method of claim 92, wherein said cis regulatory element is an endothelial cell-specific or periendothelial cell-specific promoter selected from the group consisting of PPE-1 promoter, the PPE-1-3×

promoter, the TIE-1 promoter, the TIE-2 promoter, the Endoglin promoter, the von-Willebrand promoter, the KDR/flk-1 promoter, The FLT-1 promoter, the Egr-1 promoter, the ICAM-1 promoter, the VCAM-1 promoter, the PECAM-1 promoter and the aortic carboxypeptidase-like protein (ACLP) promoter.

100. The method of claim 92, wherein said ligand binding domain is a ligand-binding domain of a cell-surface receptor.

101. The method of claim 100, wherein said cell-surface receptor is selected from the group consisting of a receptor tyrosine kinase, a receptor serine kinase, a receptor threonine kinase, a cell adhesion molecule and a phosphatase receptor.

102. The method of claim 92, wherein said cytotoxic molecule is selected from the group consisting of Fas, TNFR and TRAIL.

103. The method of claim 92, wherein said nucleic acid construct further comprises a conditionally replicating adenovirus.

94. The method of claim 94, wherein said at least a portion of the sequence set forth in SEQ ID NO:

15 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

16 in said cis regulatory element.

104. A pharmaceutical composition for down regulating angiogenesis in a tissue of a subject, the pharmaceutical composition comprising as an active ingredient a nucleic acid construct designed and configured for generating cytotoxicity in a subpopulation of angiogenic cells and a pharmaceutical acceptable carrier, said nucleic acid construct including:

(a) a first polynucleotide region encoding a chimeric polypeptide including a ligand binding domain fused to an effector domain of a cytotoxic molecule; and

(b) a second polynucleotide region encoding a cis regulatory element being for directing expression of said chimeric polypeptide in said subpopulation of angiogenic cells;

wherein said ligand binding domain is selected such that it is capable of binding a ligand present in said specific tissue or cell, whereas binding of said ligand to said ligand binding domain activates said effector domain of said cytotoxic molecule.

105. The pharmaceutical composition of claim 104, wherein said cis regulatory element includes at least a portion of the sequence set forth in SEQ ID NO:

15 covalently linked to at least a portion of the sequence set forth in SEQ ID NO;

16, the isolated polynucleotide being capable of directing transcription of a polynucleotide sequence transcriptionally linked thereto in eukaryotic cells.

106. The pharmaceutical composition of claim 105, wherein said at least a portion of the sequence set forth in SEQ ID NO:

15 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

16 in said cis regulatory element.

107. The pharmaceutical composition of claim 105, wherein said at least a portion of the sequence set forth in SEQ ID NO:

16 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

15 in said cis regulatory element.

108. The pharmaceutical composition of claim 104, wherein said cis regulatory element is an endothelial cell-specific or periendothelial cell-specific promoter selected from the group consisting of the PPE-1 promoter, the PPE-1-3×

promoter, the TIE-1 promoter, the TIE-2 promoter, the Endoglin promoter, the von Willebrand promoter, the KDR/flk-1 promoter, The FLT-1 promoter, the Egr-1 promoter, the ICAM-1 promoter, the VCAM-1 promoter, the PECAM-1 promoter and the aortic carboxypeptidase-like protein (ACLP) promoter.

109. The pharmaceutical composition of claim 104, further comprising at least one chemotherapeutic compound.

110. The pharmaceutical composition of claim 104, wherein said ligand binding domain is a ligand-binding domain of a cell-surface receptor.

111. The pharmaceutical composition of claim 110, wherein said cell-surface receptor is selected from the group consisting of a receptor tyrosine kinase, a receptor serine kinase, a receptor threonine kinase, a cell adhesion molecule and a phosphatase receptor.

112. The pharmaceutical composition of claim 104, wherein said cytotoxic molecule is selected from the group consisting of Fas, TNFR and TRAIL.

113. The pharmaceutical composition of claim 104, wherein said nucleic acid construct further comprises a conditionally replicating adenovirus.

114. A method of treating a disease or condition associated with excessive neo-vascularization, the method comprising administering a therapeutically effective amount of a nucleic acid construct designed and configured for generating cytotoxicity in a sub-population of angiogenic cells, said nucleic acid construct including:

(i) a first polynucleotide region encoding a chimeric polypeptide including a ligand binding domain fused to an effector domain of a cytotoxic molecule; and

(ii) a second polynucleotide region encoding a cis acting regulatory element being for directing expression of said chimeric polypeptide in said sub-population of angiogenic cells;

wherein said ligand binding domain is selected such that it is capable of binding a ligand present in, or provided to, said sub-population of angiogenic cells, whereas binding of said ligand to said ligand binding domain activates said effector domain of said cytotoxic molecule, thereby down-regulating angiogenesis in the tissue and treating the disease or condition associated with excessive neo-vascularization.

115. The method of claim 114, wherein said cis regulatory element includes at least a portion of the sequence set forth in SEQ ID NO:

15 covalently linked to at least a portion of the sequence set forth in SEQ ID NO;

16, the isolated polynucleotide being capable of directing transcription of a polynucleotide sequence transcriptionally linked thereto in eukaryotic cells.

116. The method of claim 115, wherein said at least a portion of the sequence set forth in SEQ ID NO:

15 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

16 in said cis regulatory element.

117. The method of claim 115, wherein said at least a portion of the sequence set forth in SEQ ID NO:

16 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

15 in said cis regulatory element.

118. The method of claim 114, further comprising administering said ligand to the subject in a manner suitable for providing said ligand to said sub-population of angiogenic cells.

119. The method of claim 114, wherein said administering said ligand to the subject is effected by a method selected from the group consisting of:

(i) systemic in-vivo administration;

(ii) ex-vivo administration to cells removed from a body of the subject, said cells subsequently reintroduced into said body of the subject; and

(iii) local in-vivo administration.

120. The method of claim 114, wherein said cis regulatory element is an endothelial cell-specific or periendothelial cell-specific promoter selected from the group consisting of the PPE-1 promoter, the PPE-1-3×

promoter, the TIE-1 promoter, the TIE-2 promoter, the Endoglin promoter, the von Willebrand promoter, the KDR/flk-1 promoter, The FLT-1 promoter, the Egr-1 promoter, the ICAM-1 promoter, the VCAM-1 promoter, the PECAM-1 promoter and the aortic carboxypeptidase-like protein (ACLP) promoter.

121. The method of claim 114, further comprising administering to said subject, in combination therewith, at least one additional therapeutic modality, said additional therapeutic modality selected capable of further potentiating cytotoxicity in a synergic manner.

122. The method of claim 121, wherein said at least one additional therapeutic modality is selected from the group comprising chemotherapy, radiotherapy, phototherapy and photodynamic therapy, surgery, nutritional therapy, ablative therapy, combined radiotherapy and chemotherapy, brachiotherapy, proton beam therapy, immunotherapy, cellular therapy and photon beam radiosurgical therapy.

123. The method of claim 114, wherein said ligand binding domain is a ligand-binding domain of a cell-surface receptor.

124. The method of claim 123, wherein said cell-surface receptor is selected from the group consisting of a receptor tyrosine kinase, a receptor serine kinase, a receptor threonine kinase, a cell adhesion molecule and a phosphatase receptor.

125. The method of claim 114, wherein said cytotoxic molecule is selected from the group consisting of Fas, TNFR and TRAIL.

126. The method of claim 114, wherein said nucleic acid construct further comprises a conditionally replicating adenovirus.

127. A method of treating a tumor in a subject, the method comprising administering a therapeutically effective amount of a nucleic acid construct designed and configured for generating cytotoxicity in cells of the tumor, said nucleic acid construct including:

(i) a first polynucleotide region encoding a chimeric polypeptide including a ligand binding domain fused to an effector domain of a cytotoxic molecule; and

(ii) a second polynucleotide region encoding a cis regulatory element being for directing expression of said chimeric polypeptide in said cells of the tumor;

wherein said ligand binding domain is selected such that it is capable of binding a ligand present in, or provided to, said cells of the tumor, whereas binding of said ligand to said ligand binding domain activates said effector domain of said cytotoxic molecule to thereby direct cytotoxicity in said cells of the tumor.

128. The method of claim 127, further comprising administering said ligand to the subject in a manner suitable for providing said ligand to said cells of the tumor.

129. The method of claim 127, wherein said cis regulatory element is selected from the group consisting of the gastrin-releasing peptide (GRP) promoter, the hTERT promoter, the Hexokinase type II promoter and the L-plastin promoter.

130. The method of claim 127, wherein said cis regulatory element includes at least a portion of the sequence set forth in SEQ ID NO:

15 covalently linked to at least a portion of the sequence set forth in SEQ ID NO;

16, the isolated polynucleotide being capable of directing transcription of a polynucleotide sequence transcriptionally linked thereto in eukaryotic cells.

131. The method of claim 130, wherein said at least a portion of the sequence set forth in SEQ ID NO:

15 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

16 in said cis regulatory element.

132. The method of claim 130, wherein said at least a portion of the sequence set forth in SEQ ID NO:

16 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

15 in said cis regulatory element.

133. The method of claim 127, wherein said nucleic acid construct further comprises a conditionally replicating adenovirus.

134. The method of claim 127, further comprising administering to said subject, in combination therewith, at least one additional therapeutic modality, said additional therapeutic modality selected capable of further potentiating cytotoxicity in a synergic manner.

135. The method of claim 134, wherein said at least one additional therapeutic modality is selected from the group comprising chemotherapy, radiotherapy, phototherapy and photodynamic therapy, surgery, nutritional therapy, ablative therapy, combined radiotherapy and chemotherapy, brachiotherapy, proton beam therapy, immunotherapy, cellular therapy and photon beam radiosurgical therapy.

136. A method of treating a disease or condition associated with ischemia, the method comprising administering a therapeutically effective amount of a nucleic acid construct designed and configured for generating angiogenesis in a sub-population of angiogenic cells, said nucleic acid construct including:

(i) a first polynucleotide region encoding a proangiogenic factor; and

(ii) a second polynucleotide region encoding a cis regulatory element being for directing expression of said proangiogenic factor in said sub-population of angiogenic cells;

thereby up-regulating angiogenesis in the tissue and treating the disease or condition associated with ischemia.

137. The method of claim 136, wherein said cis regulatory element includes at least a portion of the sequence set forth in SEQ ID NO:

15 covalently linked to at least a portion of the sequence set forth in SEQ ID NO;

16, the isolated polynucleotide being capable of directing transcription of a polynucleotide sequence transcriptionally linked thereto in eukaryotic cells.

138. The method of claim 137, wherein said at least a portion of the sequence set forth in SEQ ID NO:

15 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

16 in said cis regulatory element.

139. The method of claim 137, wherein said at least a portion of the sequence set forth in SEQ ID NO:

16 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

15 in said cis regulatory element.

140. The method of claim 136, wherein said cis regulatory element is an endothelial cell-specific or periendothelial cell-specific promoter selected from the group consisting of the PPE-1 promoter, the PPE-1-3×

promoter, the TIE-1 promoter, the TIE-2 promoter, the Endoglin promoter, the von Willebrand promoter, the KDR/flk-1 promoter, The FLT-1 promoter, the Egr-1 promoter, the ICAM-1 promoter, the VCAM-1 promoter, the PECAM-1 promoter and the aortic carboxypeptidase-like protein (ACLP) promoter.

141. The method of claim 136, wherein said disease or condition associated with ischemia is selected from the group consisting of wound healing, ischemic stroke, ischemic heart disease and gastrointestinal lesions.

142. The method of claim 136, wherein said nucleic acid construct further comprises a conditionally replicating adenovirus.

143. A method of down-regulating angiogenesis in a tissue of a subject, the method comprising:

(a) expressing in the tissue a nucleic acid construct designed and configured for cytotoxicity in angiogenic cells, said nucleic acid construct including;

(i) a first polynucleotide region encoding a suicide gene and

(ii) a second polynucleotide region encoding a cis acting regulatory element capable of directing expression of said suicide gene in said angiogenic cells; and

(b) administering to the subject a therapeutic amount of a prodrug sufficient to cause apoptosis of said tissue when said prodrug is converted to a toxic compound by said suicide gene

thereby down-regulating angiogenesis in the tissue.

144. The method of claim 143, wherein said cis regulatory element includes at least a portion of the sequence set forth in SEQ ID NO:

15 covalently linked to at least a portion of the sequence set forth in SEQ ID NO;

16, the isolated polynucleotide being capable of directing transcription of a polynucleotide sequence transcriptionally linked thereto in eukaryotic cells.

145. The method of claim 143, wherein said nucleic acid construct further comprises a conditionally replicating adenovirus.

146. The method of claim 143, wherein said suicide gene is selected from the group consisting of thymidine kinase of herpes simplex virus, thymidine kinase of varicella zoster virus and bacterial cytosine deaminase.

147. The method of claim 143, wherein said prodrug is selected from the group consisting of ganciclovir, aciclovir, 1-5-iodouracil FIAU, 5-fluorocytosine, 6-methoxypurine arabinoside and their derivatives.

148. The method of claim 143, wherein said suicide gene is thymidine kinase of herpes simplex virus and the prodrug is ganciclovir, aciclovir, FIAU or their derivatives.

149. The method of claim 143, wherein the suicide gene is bacteria cytosine deaminase and said prodrug is 5-fluorocytosine or its derivatives.

150. The method of claim 143, wherein said suicide gene is varicella zoster virus thymidine kinase and said prodrug is 6-methoxypurine arabinoside or its derivatives.

151. The method of claim 143, further comprising administering to said subject, in combination therewith, at least one additional therapeutic modality, said additional therapeutic modality selected capable of further potentiating cytotoxicity in a synergic manner.

152. The method of claim 151, wherein said at least one additional therapeutic modality is selected from the group comprising chemotherapy, radiotherapy, phototherapy and photodynamic therapy, surgery, nutritional therapy, ablative therapy, combined radiotherapy and chemotherapy, brachiotherapy, proton beam therapy, immunotherapy, cellular therapy and photon beam radiosurgical therapy.

153. A pharmaceutical composition for down regulating angiogenesis in a tissue of a subject, the pharmaceutical composition comprising as an active ingredient a nucleic acid construct designed and configured for generating cytotoxicity in angiogenic cells and a pharmaceutical acceptable carrier, said nucleic acid construct including:

(a) a first polynucleotide region encoding a suicide gene, said suicide gene being capable of converting a prodrug to a toxic compound and

(b) a second polynucleotide region encoding a cis acting regulatory element capable of directing expression of said suicide gene in said angiogenic cells.

154. The pharmaceutical composition of claim 153, wherein said cis regulatory element includes at least a portion of the sequence set forth in SEQ ID NO:

15 covalently linked to at least a portion of the sequence set forth in SEQ ID NO;

16, the isolated polynucleotide being capable of directing transcription of a polynucleotide sequence transcriptionally linked thereto in eukaryotic cells.

155. The pharmaceutical composition of claim 154, wherein said at least a portion of the sequence set forth in SEQ ID NO:

15 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

16 in said cis regulatory element.

156. The pharmaceutical composition of claim 154, wherein said at least a portion of the sequence set forth in SEQ ID NO:

16 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

15 in said cis regulatory element.

157. The pharmaceutical composition of claim 153, wherein said cis regulatory element is an endothelial cell-specific or periendothelial cell-specific promoter selected from the group consisting of the PPE-1 promoter, the PPE-1-3×

promoter, the TIE-1 promoter, the TIE-2 promoter, the Endoglin promoter, the von Willebrand promoter, the KDR/flk-1 promoter, The FLT-1 promoter, the Egr-1 promoter, the ICAM-1 promoter, the VCAM-1 promoter, the PECAM-1 promoter and the aortic carboxypeptidase-like protein (ACLP) promoter.

158. The pharmaceutical composition of claim 153, wherein said nucleic acid construct further comprises a conditionally replicating adenovirus.

159. The pharmaceutical compound of claim 153, wherein said suicide gene is selected from the group consisting of thymidine kinase of herpes simplex virus, thymidine kinase of varicella zoster virus and bacterial cytosine deaminase.

160. The pharmaceutical compound of claim 153, wherein said prodrug is selected from the group consisting of ganciclovir, aciclovir, 1-5-iodouracil FIAU, 5-fluorocytosine, 6-methoxypurine arabinoside and their derivatives.

161. The pharmaceutical compound of claim 153, wherein said suicide gene is thymidine kinase of herpes simplex virus and the prodrug is ganciclovir, aciclovir, FIAU or their derivatives.

162. The pharmaceutical compound of claim 153, wherein the suicide gene is bacteria cytosine deaminase and said prodrug is 5-fluorocytosine or its derivatives.

163. The pharmaceutical compound of claim 153, wherein said suicide gene is varicella zoster virus thymidine kinase and said prodrug is 6-methoxypurine arabinoside or its derivatives.

164. A nucleic acid construct comprising:

(a) a first polynucleotide region encoding a suicide gene, said suicide gene being capable of converting a prodrug to a toxic compound and

(b) a second polynucleotide region encoding a cis regulatory element capable of directing expression of said suicide gene in angiogenic cells.

165. The nucleic acid construct of claim 164, wherein said cis regulatory element includes at least a portion of the sequence set forth in SEQ ID NO:

15 covalently linked to at least a portion of the sequence set forth in SEQ ID NO;

16, the isolated polynucleotide being capable of directing transcription of a polynucleotide sequence transcriptionally linked thereto in eukaryotic cells.

166. The nucleic acid construct of claim 165, wherein said at least a portion of the sequence set forth in SEQ ID NO:

15 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

16 in said cis regulatory element.

167. The nucleic acid construct of claim 165, wherein said at least a portion of the sequence set forth in SEQ ID NO:

16 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

15 in said cis regulatory element.

168. The nucleic acid construct of claim 164, wherein said cis regulatory element is an endothelial cell-specific or periendothelial cell-specific promoter selected from the group consisting of the PPE-1 promoter, the PPE-1-3×

promoter, the TIE-1 promoter, the TIE-2 promoter, the Endoglin promoter, the von Willebrand promoter, the KDR/flk-1 promoter, The FLT-1 promoter, the Egr-1 promoter, the ICAM-1 promoter, the VCAM-1 promoter, the PECAM-1 promoter and the aortic carboxypeptidase-like protein (ACLP) promoter.

169. The method of claim 164, wherein said nucleic acid construct further comprises a conditionally replicating adenovirus.

170. The nucleic acid construct of claim 164, wherein said suicide gene is selected from the group consisting of thymidine kinase of herpes simplex virus, thymidine kinase of varicella zoster virus and bacterial cytosine deaminase.

171. The nucleic acid construct of claim 164, wherein said prodrug is selected from the group consisting of ganciclovir, aciclovir, 1-5-iodouracil FIAU, 5-fluorocytosine, 6-methoxypurine arabinoside and their derivatives.

172. The nucleic acid construct of claim 164, wherein said suicide gene is thymidine kinase of herpes simplex virus and the prodrug is ganciclovir, aciclovir, FIAU or their derivatives.

173. The nucleic acid construct of claim 164, wherein the suicide gene is bacteria cytosine deaminase and said prodrug is 5-fluorocytosine or its derivatives.

174. The nucleic acid construct of claim 164, wherein said suicide gene is varicella zoster virus thymidine kinase and said prodrug is 6-methoxypurine arabinoside or its derivatives.

175. A eukaryotic cell transformed with the nucleic acid construct of claim 164.

176. A method of down-regulating angiogenesis in a tissue of a subject, the method comprising administering to the subject a nucleic acid construct designed and configured for generating cytotoxicity in angiogenic cells, said nucleic acid construct including:

(a) a first polynucleotide region encoding a suicide gene; and

(b) a second polynucleotide region encoding a cis regulatory element capable of directing expression of said suicide gene in said angiogenic cells;

wherein said suicide gene is selected capable of converting a prodrug to a toxic compound capable of causing cytotoxicity, thereby down-regulating angiogenesis in the tissue.

177. The method of claim 176, wherein said cis regulatory element includes at least a portion of the sequence set forth in SEQ ID NO:

15 covalently linked to at least a portion of the sequence set forth in SEQ ID NO;

16, the isolated polynucleotide being capable of directing transcription of a polynucleotide sequence transcriptionally linked thereto in eukaryotic cells.

178. The method of claim 177, wherein said at least a portion of the sequence set forth in SEQ ID NO:

15 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

16 in said cis regulatory element.

179. The method of claim 177, wherein said at least a portion of the sequence set forth in SEQ ID NO:

16 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

15 in said cis regulatory element.

180. The method of claim 176, wherein said cis acting regulatory element is an endothehal cell-specific or periendothelial cell-specific promoter selected from the group consisting of the PPE-1 promoter, the PPE-1-3×

promoter, the TIE-1 promoter, the TIE-2 promoter, the Endoglin promoter, the von Willebrand promoter, the KDR/flk-1 promoter, The FLT-1 promoter, the Egr-1 promoter, the ICAM-1 promoter, the VCAM-1 promoter, the PECAM-1 promoter and the aortic carboxypeptidase-like protein (ACLP) promoter.

181. The method of claim 176, wherein said nucleic acid construct further comprises a conditionally replicating adenovirus.

182. The method of claim 176, wherein said suicide gene is selected from the group consisting of thymidine kinase of herpes simplex virus, thymidine kinase of varicella zoster virus and bacterial cytosine deaminase.

183. The method of claim 176, wherein said prodrug is selected from the group consisting of ganciclovir, aciclovir, 1-5-iodouracil FIAU, 5-fluorocytosine, 6-methoxypurine arabinoside and their derivatives.

184. The method of claim 176, wherein said suicide gene is thymidine kinase of herpes simplex virus and the prodrug is ganciclovir, aciclovir, FIAU or their derivatives.

185. The method of claim 176, wherein the suicide gene is bacteria cytosine deaminase and said prodrug is 5-fluorocytosine or its derivatives.

186. The method of claim 176, wherein said suicide gene is varicella zoster virus thymidine kinase and said prodrug is 6-methoxypurine arabinoside or its derivatives.

187. A method of treating a disease or condition associated with excessive neo-vascularization, the method comprising administering a therapeutically effective amount of a nucleic acid construct designed and configured for cytotoxicity in angiogenic cells, said nucleic acid construct including:

(i) a first polynucleotide region encoding a suicide gene; and

(ii) a second polynucleotide region encoding a cis acting regulatory element capable of directing expression of said suicide gene in said angiogenic cells;

wherein said suicide gene is selected capable of converting a prodrug to a toxic compound capable of causing cytotoxicity, thereby down-regulating angiogenesis in the tissue and treating the disease or condition associated with excessive neo-vascularization.

188. The method of claim 187, wherein said cis regulatory element includes at least a portion of the sequence set forth in SEQ ID NO:

15 covalently linked to at least a portion of the sequence set forth in SEQ ID NO;

16, the isolated polynucleotide being capable of directing transcription of a polynucleotide sequence transcriptionally linked thereto in eukaryotic cells.

189. The method of claim 188, wherein said at least a portion of the sequence set forth in SEQ ID NO:

15 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

16 in said cis regulatory element.

190. The method of claim 188, wherein said at least a portion of the sequence set forth in SEQ ID NO:

16 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

15 in said cis regulatory element.

191. The method of claim 187, further comprising administering said prodrug to the subject in a manner suitable for providing said prodrug to said angiogenic cells.

192. The method of claim 187, wherein said administering said prodrug to the subject is effected by a method selected from the group consisting of:

(i) systemic in-vivo administration;

(ii) ex-vivo administration to cells removed from a body of the subject, said cells subsequently reintroduced into said body of the subject; and

(iii) local in-vivo administration.

193. The method of claim 187, wherein said cis regulatory element is an endothelial cell-specific or periendothelial cell-specific promoter selected from the group consisting of the PPE-1 promoter, the PPE-1-3×

promoter, the TIE-1 promoter, the TIE-2 promoter, the Endoglin promoter, the von Willebrand promoter, the KDR/flk-1 promoter, The FLT-1 promoter, the Egr-1 promoter, the ICAM-1 promoter, the VCAM-1 promoter, the PECAM-1 promoter and the aortic carboxypeptidase-like protein (ACLP) promoter.

194. The method of claim 187, wherein said nucleic acid construct further comprises a conditionally replicating adenovirus.

195. The method of claim 187, wherein said suicide gene is selected from the group consisting of thymidine kinase of herpes simplex virus, thymidine kinase of varicella zoster virus and bacterial cytosine deaminase.

196. The method of claim 187, wherein said prodrug is selected from the group consisting of ganciclovir, aciclovir, 1-5-iodouracil FIAU, 5-fluorocytosine, 6-methoxypurine arabinoside and their derivatives.

197. The method of claim 187, further comprising administering to said subject, in combination therewith, at least one additional therapeutic modality, said additional therapeutic modality selected capable of further potentiating cytotoxicity in a synergic manner.

198. The method of claim 197, wherein said at least one additional therapeutic modality is selected from the group comprising chemotherapy, radiotherapy, phototherapy and photodynamic therapy, surgery, nutritional therapy, ablative therapy, combined radiotherapy and chemotherapy, brachiotherapy, proton beam therapy, immunotherapy, cellular therapy and photon beam radiosurgical therapy.

199. A method of treating a tumor in a subject, the method comprising administering a therapeutically effective amount of a nucleic acid construct designed and configured for generating cytotoxicity in cells of the tumor, said nucleic acid construct including:

(i) a first polynucleotide region encoding a suicide gene; and

(ii) a second polynucleotide region encoding a cis acting regulatory element capable of directing expression of said suicide gene in said cells of the tumor;

wherein said suicide gene is selected capable of converting a prodrug to a toxic compound capable of causing cytotoxicity in said cells of the tumor.

200. The method of claim 199, further comprising administering said prodrug to the subject in a manner suitable for providing said prodrug to said cells of the tumor.

201. The method of claim 199, wherein said cis regulatory element includes at least a portion of the sequence set forth in SEQ ID NO:

15 covalently linked to at least a portion of the sequence set forth in SEQ ID NO;

16, the isolated polynucleotide being capable of directing transcription of a polynucleotide sequence transcriptionally linked thereto in eukaryotic cells.

202. The method of claim 201, wherein said at least a portion of the sequence set forth in SEQ ID NO:

15 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

16 in said cis regulatory element.

203. The method of claim 201, wherein said at least a portion of the sequence set forth in SEQ ID NO:

16 is positioned upstream of said at least a portion of the sequence set forth in SEQ ID NO;

15 in said cis regulatory element.

204. The method of claim 199, wherein said nucleic acid construct further comprises a conditionally replicating adenovirus.

205. The method of claim 199, wherein said suicide gene is selected from the group consisting of thymidine kinase of herpes simplex virus, thymidine kinase of varicella zoster virus and bacterial cytosine deaminase.

206. The method of claim 199, wherein said prodrug is selected from the group consisting of ganciclovir, aciclovir, 1-5-iodouracil FIAU, 5-fluorocytosine, 6-methoxypurine arabinoside and their derivatives.

207. The method of claim 199, further comprising administering to said subject, in combination therewith, at least one additional therapeutic modality, said additional therapeutic modality selected capable of further potentiating cytotoxicity in a synergic manner.

208. The method of claim 207, wherein said at least one additional therapeutic modality is selected from the group comprising chemotherapy, radiotherapy, phototherapy and photodynamic therapy, surgery, nutritional therapy, ablative therapy, combined radiotherapy and chemotherapy, brachiotherapy, proton beam therapy, immunotherapy, cellular therapy and photon beam radiosurgical therapy.