Li, BinZhang, GuangsenLi, CuiLi, RuijuanLu, JingchenHe, ZhengxiWang, QuanPeng, ZhenziWang, JunDong, YepingZhang, ChunfangTan, Jie QiongBahri, NacefWang, YuexiangDuan, Chaojun2017-12-062017Li, B., G. Zhang, C. Li, R. Li, J. Lu, Z. He, Q. Wang, et al. 2017. “Lyn mediates FIP1L1-PDGFRA signal pathway facilitating IL-5RA intracellular signal through FIP1L1-PDGFRA/JAK2/Lyn/Akt network complex in CEL.” Oncotarget 8 (39): 64984-64998. doi:10.18632/oncotarget.11401. http://dx.doi.org/10.18632/oncotarget.11401.http://nrs.harvard.edu/urn-3:HUL.InstRepos:34492144The Fip1-like1 (FIP1L1)–platelet-derived growth factor receptor alpha (PDGFRA) (F/P) oncogene can cause chronic eosinophilic leukemia (CEL), but requires IL-5 cytokine participation. In this study, we investigate the mechanism of F/P in collaboration with IL-5 in CEL. The results showed that Lyn, a key effector in the IL-5-motivated eosinophil production, is extensively activated in F/P-positive CEL cells. Lyn can associate and phosphorylate IL-5 receptor α (IL-5RA) in F/P-positive cells. Moreover, the activation of Lyn and IL-5R kinase were strengthened when the cells were stimulated by IL-5. Lyn inhibition in F/P-positive CEL cells attenuated cellular proliferation, induced apoptosis, and blocked cell migration and major basic protein (MBP) release. We identified the FIP1L1-PDGFRA/JAK2/Lyn/Akt complex in the F/P-expressing cells which can be disrupted by dual inhibition of JAK2 and Lyn, repressing cell proliferation in both EOL-1(F/P-positive human eosinophilic cell line) and imatinib-resistance (IR) cells. Altogether, our data demonstrate that Lyn is a vital downstream kinase activated by F/P converged with IL-5 signals in CEL cells. Lyn activate and expand IL-5RA intracellular signaling through FIP1L1-PDGFRA/JAK2/Lyn/Akt network complex, provoking eosinophils proliferation and exaggerated activation manifested as CEL.en-USLynCELJournal Article2017-12-0610.18632/oncotarget.11401