The Design and Study of Anticancer Therapeutics Inspired by Natural Substrates of LAT1

PROJECT SUMMARY Cancer’s uncontrolled cell proliferation is supported in part by the overexpression of the large neutral amino acid transporter 1 (LAT1). LAT1 is key in meeting the unusually high nutrient demand of cancer cells for natural- occurring hydrophobic amino acids. The proposed work is significant because current drug treatments suffer from limitations involving the poor selectivity for cancer cells over healthy cells, inefficient drug-uptake, and treatment-resistance which often occurs with progression and recurrence of the disease. Furthermore, a major roadblock in drug development for cancerous tumors is the inability of many small molecules to penetrate into tumor cells. An effective strategy for addressing these drawbacks involves targeting drugs that are amenable for uptake via LAT1. The expected outcome in designing structures that can serve as LAT1 substrates is targeted delivery through enhanced drug selectivity for cancer cells over healthy cells. The overarching goal of this project is to develop novel 1,2,3-triazole-based amino acid chemotherapeutics as structural analogues of natural LAT1 substrates. 1,2,3-Triazoles are important scaffolds in compounds with a wide range of biological activities, including anticancer activity. In addition, these units are often attached to other biologically active molecules to enhance potency. Anticancer drug designs that take advantage of the therapeutic potential of the 1,2,3-triazole rings in combination with the uptake efficiency that can be achieved via LAT1 are innovative, novel, and wide open for exploration. The approach to this project will be carried out with two specific aims, (1) the design and synthesis of the triazole-based amino acid-drug assemblies and (2) in vitro characterization of drug candidates. In the first aim, we will design three classes of amino acid analogues containing the 1,2,3-triazolyl rings linked to aromatic (Ar) moieties with known anticancer activity. The core skeletal designs will consist of an unnatural amino acid backbone, the natural amino acid tyrosine, and meta-tyrosine; the latter two are highly compatible with LAT1. Biological evaluation of the final triazole amino acid-drug assemblies and their precursors will be used to decipher the structure-activity relationship for anticancer activity and cellular uptake. The second aim will focus on the biological studies. These investigations will use cell viability studies to probe the anticancer properties of the compounds developed in aim 1. The second aim will also probe intracellular delivery; morphological changes in the cells post drug administration; and signaling pathways and biochemical parameters the molecules are predicted to target (p53 tumor suppressor gene function and reactive oxygen species (ROS) production).