Apolipoprotein A-I mimetic peptide 4F suppresses tumor-associated macrophages and pancreatic cancer progression

// Meiyu Peng 1, 2, * , Qi Zhang 3, 2, * , Yingnan Cheng 2, * , Shuyu Fu 2, 4 , Huipeng Yang 2 , Xiangdong Guo 2 , Jieyou Zhang 2 , Lina Wang 1 , Lijuan Zhang 2 , Zhenyi Xue 2 , Yan Li 2 , Yurong Da 2 , Zhi Yao 2 , Liang Qiao 5 and Rongxin Zhang 2, 6 1 Department of Immunology, School of Clinical Medicine, Weifang Medical University, Weifang, China 2 Laboratory of Immunology and Inflammation, Department of Immunology, Key Laboratory of Immune Microenvironment and Diseases of Educational Ministry of China, Tianjin Key Laboratory of Molecular and Cellular Immunology, Tianjin Medical University, Tianjin, China 3 Institute of Integrative Medicines for Acute Abdominal Diseases, Nankai Hospital, Tianjin, China 4 Institute of Human Virology, Sun Yat-Sen University, Guangzhou, China 5 Storr Liver Unit, Westmead Institute for Medical Research, the University of Sydney and Westmead Hospital, Westmead, New South Wales, Australia 6 Laboratory of Immunology and Inflammation, School of Life Science and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou, China * These authors contributed equally to this work Correspondence to: Rongxin Zhang, email: rongxinz@yahoo.com Liang Qiao, email: liang.qiao@sydney.edu.au Meiyu Peng, email: pmy-107@163.com Yurong Da, email: dayr@tmu.edu.cn Keywords: pancreatic cancer, L-4F, inflammation, tumor-associated macrophages, STAT3 Received: June 09, 2017 Accepted: September 08, 2017 Published: September 22, 2017 ABSTRACT Pancreatic cancer is an aggressive malignancy that is unresponsive to conventional radiation and chemotherapy. Therefore, development of novel immune therapeutic strategies is urgently needed. L-4F, an Apolipoprotein A-I (ApoA-I) mimetic peptide, is engineered to mimic the anti-inflammatory and anti-oxidative functionalities of ApoA-I. In this work, H7 cells were orthotopically implanted in C57BL/6 mice and treated with L-4F. Then, pancreatic cancer progression and the inflammatory microenvironment were investigated in vivo . The cytotoxicity of L-4F toward H7 cells was assessed in vitro . Furthermore, we investigated the effects of L-4F on macrophage polarization by analyzing the polarization and genes of mouse bone marrow-derived macrophages in vitro . The results show that L-4F substantially reduced the tumorigenicity of H7 cells. L-4F inhibited inflammation by reducing the accumulation of inflammatory cells, such as IL-17A-, IL-4-, GM-CSF-, IL-1β-, and IL-6-producing cells and Th1 and Th17. Notably, L-4F also decreased the percentage of macrophages in tumor tissues, especially M2 macrophages (CD11b + F4/80 + CD206 + ), which was also confirmed in vitro . Additionally, the expression of the M2 marker genes Arg1 , MRC1 , and CCL22 and the inflammatory genes IL-6 , iNOS , and IL-12 was decreased by L-4F, indicating that L-4F prevents M2 type macrophage polarization. However, L-4F could not directly attenuate H7 cell invasion or proliferation and did not induce apoptosis. In addition, L-4F potently down-regulated STAT3, JNK and ERK signaling pathways but not affects the phosphorylation of p38 in RAW 264.7 cells. These results suggest that L-4F exhibits an effective therapeutic effect on pancreatic cancer progression by inhibiting tumor-associated macrophages and inflammation.