The present invention provides nucleic acid constructs, expression vectors, transgenic cell and methods of making and using the same, wherein the nucleic acid construct includes a synthetic promoter designed using selected PDX-1 activation sites such as those observed in the human insulin promoter (HIP). In illustrative working embodiments of the invention, an exogenous nucleic acid fragment encoding thymidine kinase is operably linked to the synthetic promoter which is then shown to regulate the expression of this polypeptide.