Poster Presentation 32nd Lorne Cancer 2020

Unravelling the Full Pathophysiological Substrate Repertoire of the ADAM17 Protease in Lung Adenocarcinoma (#341)

Mohamed I. Saad 1 , Ching-Seng Ang 2 , Nicholas Williamson 2 , Stefan Rose-John 3 , Brendan Jenkins 1
  1. Hudson Institute of Medical Research, Monash University, Clayton, Victoria, Australia
  2. Bio21 Mass Spectrometry and Proteomics Facility, The University of Melbourne, Parkville, Victoria, Australia
  3. Institute of Biochemistry, Christian-Albrechts-University, Kiel, Germany

A disintegrin and metalloproteinase 17 (ADAM17) is an important mediator of inflammatory responses and cancer development through the shedding of bioactive inflammatory cytokines and protumourigenic mediators, including tumour necrosis factor-α (TNFα), soluble interleukin-6 receptor (sIL-6R), epidermal growth factor receptor (EGFR) ligands and Notch receptor. ADAM17 is implicated in the pathogenesis of many inflammatory conditions and cancers including lung adenocarcinoma and colorectal cancer. However, the full substrate degradome of ADAM17 that is involved in these diseases is yet to be identified. To address this, we employed unbiased discovery-based high-throughput quantitative approaches including global proteomics, phosphoproteomics and the terminal amine isotopic labelling of substrates (TAILS) approach to profile ADAM17-specific substrates under normal and pathological conditions. We analysed bulk tissues from wildtype mice and Adam17ex/ex mice, which are homozygous for the hypomorphic Adam17ex allele resulting in a significant reduction in ADAM17 expression. Also, we analysed the lungs of the tumour bearing KrasG12D lung adenocarcinoma mouse model and lungs of KrasG12D:Adam17ex/ex mice which demonstrated protection against lung adenocarcinoma development. The expression of candidate ADAM17 substrates discovered was validated by immunoblotting and/or ELISA. CRISPR-Cas9 technology was employed to investigate the role of the discovered substrates in the viability and proliferation of human lung adenocarcinoma cell lines. Collectively, this study unravels the full substrate degradome of the protease ADAM17 in homeostasis and under pathological conditions, and reveals clinically relevant ADAM17 substrates that could be exploited to treat and diagnose a myriad of disease modalities, including lung adenocarcinoma.