Abstract 2204: A proteomic landscape of diffuse-type gastric cancer
Authors: Ge Sai , Xia Xia , Ding Chen , Zhen Bei , Zhou Quan , Feng Jinwen , Yuan Jiajia , Chen Rui , Li Yumei , Ge Zhongqi , Ji Jiafu , Zhang Lianhai , Wang Jiayuan , Li Zhongwu , Lai Yumei , Hu Ying , Li Yanyan , Li Yilin , Gao Jing , Chen Lin , Xu Jianming , Zhang Chunchao , Jung Sung Yun , Liu Mingwei , Song Lei , Liu Wanlin , Guo Gaigai , Gong Tongqing , Huang Yin , Qiu Yang , Shi Tieliu , Zhu Weimin , Wang Yi , He Fuchu , Shen Lin , Qin Jun ,   CNHPP
Published: July 2017

Abstract
Gastric cancer is a heterogeneous disease characterized by poor clinical outcomes and limited targeted treatment options. Among them, diffuse-type gastric cancer (DGC) is the subtype with worst prognosis. Here we describe the first proteomic landscape of DGC. We carried out proteome profiling and targeted exome DNA sequencing of 84 DGC samples. We analyzed the 1,008 (168 x 6) raw files together for uniformed quality control and protein identification with 1% global protein false discovery rate (FDR), which resulted in the identification of 11,340 gene products (GPs). A SAM (significance analysis of microarray) analysis identified 1,641 proteins as differentially expressed between T (tumor) and N (nearby) with statistical significance (FDR q value&lt;0.01 by SAM and differential expression ratio&gt;0.5/ &lt; -0.5), including 1,211 up-regulated and 430 down-regulated GPs. Gene Ontology annotation indicated that tumor proteomes were significantly enriched in cell cycle, DNA replication, checkpoint, E2F, WNT, p53 signaling, epithelial mesenchymal transition (EMT), and inflammation/cytokine-receptor interaction pathways, and the proteomes of the nearby tissues are enriched in metabolism pathways, such as fatty acid metabolism, oxidative phosphorylation, and amino acid metabolism. Notably, many gastric makers (ANXA10, VSIG1, CLDN18, CTSE, TFF2, MUC5AC and MUC6) and signature proteins for stomach functions, including digestion, absorption, secretion, and stomach acid generation (PGC, GIF, GAST, and ATP4A), were lost in tumors. Based on proteome profiling alone, DGC can be subtyped into 3 major classes (PX1-3) that exhibit distinct proteome features and correlate with distinct clinical outcomes (Gehan-Breslow-Wilcoxon P = 0.024). PX1 exhibits proteome stability and the best overall survival; PX2 exhibits dysregulation in DNA replication and cell cycle, and is most sensitive to chemotherapy; PX3 features hyper-activated immune response and is not responsive to chemotherapy. We identified seven-marker proteins that can stratify DGC patients into these three subtypes, opening a door for proteome subtyping in clinical application and intervention. Furthermore, we nominated drug target candidates taking into consideration both the altered DGC proteome and association data with patients’ overall survival. This study revealed the altered signaling pathways in DGC and demonstrated the advantage of proteomic approach in molecular subtyping of cancer.
Citation Format: Sai Ge, Xia Xia, Chen Ding, Bei Zhen, Quan Zhou, Jinwen Feng, Jiajia Yuan, Rui Chen, Yumei Li, Zhongqi Ge, Jiafu Ji, Lianhai Zhang, Jiayuan Wang, Zhongwu Li, Yumei Lai, Ying Hu, Yanyan Li, Yilin Li, Jing Gao, Lin Chen, Jianming Xu, Chunchao Zhang, Sung Yun Jung, Mingwei Liu, Lei Song, Wanlin Liu, Gaigai Guo, Tongqing Gong, Yin Huang, Yang Qiu, Tieliu Shi, Weimin Zhu, Yi Wang, Fuchu He, Lin Shen, Jun Qin, CNHPP. A proteomic landscape of diffuse-type gastric cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2204. doi:10.1158/1538-7445.AM2017-2204