A novel nucleic acid construct for down-regulating angiogenesis in a tissue of a subject is provided. The nucleic acid construct includes: (a) a first polynucleotide region encoding a chimeric polypeptide including a ligand binding domain fused to an effector domain of an apoptosis signaling molecule; and (b) a second polynucleotide region encoding a cis acting regulatory element being for directing expression of the chimeric polypeptide in a specific tissue or cell; wherein the ligand binding domain is selected such that it is capable of binding a ligand present in the specific tissue or cell, whereas binding of the ligand to the ligand binding domain activates the effector domain of the apoptosis signaling molecule. Also provided are methods of utilizing this nucleic acid construct for treating diseases characterized by excessive or aberrant neo-vascularization or cell growth.