Gefitinib inhibits M2-1ike polarization of tumor- associated macrophages in Lewis lung cancer by targeting the STAT6 signaling pathway

• Published in: 中国药理学报：英文版 2017, Vol.38 (11), p.1501-1511
• Main Authors: Muhammad TARIQ, Jie-qiong ZHANG, Gui-kai LIANG, Qiao-jun HE, Ling DING, Bo YANG
• Format: Article
• Language: English
• ISSN: 1671-4083; 1745-7254

M2-1ike polarized tumor-associated macrophages （TAMs） play a pivotal role in promoting cancer cell growth, invasion, metastasis and angiogenesis. The identification of M2-1ike TAMs during tumor progression is an attractive approach for cancer therapy. In this study, we investigated the relevance of macrophage polarization and the antitumor effect of gefitinib in Lewis Lung cancer （LLC） in vitro and in vivo. Gefitinib at a concentration below 2.5 pmol/L did not cause significant growth inhibition on LLC and RAW 264.7 cell lines and bone marrow-derived macrophage （BMDMs）. However, a small concentration of gefitinib （0.62 pmol/L） significantly inhibited IL-13- induced M2-1ike polarization of macrophages, evidenced by the decreased expression of the M2 surface markers CD206 and CD163, down-regulation of specific M2-marker genes （Mrcl, Yml, Fizz1, Argl, 11_-10 and CCL2） as well as inhibition of M2-1ike macrophagemediated invasion and migration of LLC cells. In RAW 264.7 cells, gefitinib inhibits IL-13-induced phosphorylation of STAT6, which was a crucial signaling pathway in macrophage M2-1ike polarization. In LLC mice metastasis model, oral administration of gefitinib （75 mg.kg-1.d-1, for 21 d） significantly reduced the number of lung metastasis nodules, down-regulated the expression of M2 marker genes and the percentages CD206＋ and CD68＋ macrophages in tumor tissues. These results demonstrated that gefitinib effectively inhibits M2-1ike polarization both in vitro and in vivo, revealing a novel potential mechanism for the chemopreventative effect of gefitinib.