Abstract 21: Quantitative FRET technology for SUMOylation cascade and high-throughput screening assay for SUMOylation inhibitor in cancer drug discovery

Abstract

The ubiquitin–proteasome system and ubiquitin-like protein pathways, such as SUMOylation, are critical in protein homeostasis and activities in vivo and are emerging as a new strategy to treat many acute and chronic human diseases, such as cancers. Although various kinase inhibitors have been developed as target-based therapy, solid tumors are still challenges in clinical therapy because various resistant are developed after kinase inhibitor treatments, and therapeutic agents with novel mechanisms are urgently needed. SUMO has been shown to modify various critical proteins, such as p53, MDM2, Estrogen receptor and androgen receptors. More recently, a genome-wide siRNA screening shown that inhibition of SUMO E1 ligases can lead to synergistically lethality of c-Myc overexpressed breast cancer cells. However, so far, specific inhibitor of SUMOylation is still not available for the community. Fig. 1. SUMOylation in human diseases and quantitative systems biology approach for basic and translational research of SUMOylation. We developed a novel quantitative Förster resonance energy transfer (FRET) technology platform for both basic kinetics parameter determinations and high-through screening(HTS) assays for SUMOylation cascade. The novel theoretical and experimental procedures for protein interactions affinity(Kd) determinations in the SUMOylation cascade, including the interaction between SUMO1 and its E2 ligase, Ubc9, E1 heterodimers(Aos1 and Uba2), E1 and E2 interactions(Uba2 and Ubc9), and E2 and substrate interactions(Ubc9 and RanGap1c) and protease kinetics, Kcat/KM of SENP1 endopeptidase activity have been developed in a systems biology manner. The data are in good agreement with traditional methods. Multiple FRET-based HTS assays have also been developed and HTS campaigns have led to very promising hit that can preferentially kill Non-small cell lung cancer cells. The novel SUMOylation inhibitor can be used for cancer treatments by synergistically lethality strategy. Citation Format: Jiayu Liao, Hilda Wiryawan, Yang Li, Yang Song, Yan Liu, Jiacong You, Ling Jiang, Harbani Kaur Malik, Amanda N. Saavedra, Sophie Qu. Quantitative FRET technology for SUMOylation cascade and high-throughput screening assay for SUMOylation inhibitor in cancer drug discovery. [abstract]. In: Proceedings of the AACR Special Conference: Cancer Susceptibility and Cancer Susceptibility Syndromes; Jan 29-Feb 1, 2014; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(23 Suppl):Abstract nr 21. doi:10.1158/1538-7445.CANSUSC14-21