Role of EGFL7/EGFR-signaling pathway in migration and invasion of growth hormone-producing pituitary adenomas

• DOI: 10.1007/s11427-018-9320-4
• Publication Date: 2018-06-28T02:43:53Z
• Authors: Qian Liu; Junwen Zhang; Hua Gao; Taoyang Yuan; Jie Kang; Lu Jin; Songbai Gui; Yazhuo Zhang
• Keywords: Adenoma; 0301 basic medicine; EGF Family of Proteins; Calcium-Binding Proteins; Endothelial Growth Factors; Tyrphostins; Rats; ErbB Receptors; Mice; 03 medical and health sciences; Cell Movement; Cell Line, Tumor; Quinazolines; Animals; Humans; Neoplasm Invasiveness; RNA Interference; Enzyme Inhibitors; Growth Hormone-Secreting Pituitary Adenoma; Signal Transduction

Currently, the primary therapeutic strategy for most growth hormone-producing pituitary adenomas (GHPA) is surgery. Due to the invasiveness of GHPA, high recurrence has limited the benefit of complete adenoma removal surgery. Epidermal growth factor-like domain 7 (EGFL7) is a secreted factor implicated in tumor angiogenesis, growth, invasiveness and metastasis in GHPA. Herein, we observed that the expression level of EGFL7 and p-EGFR in invasive GHPA was much higher than that of non-invasive GHPA. The overexpression of EGFL7 was positively correlated with activation of EGFR (p-EGFR). Noticeably, EGFL7 knockdown significantly inhibited activation of EGFR signaling cascades, including p-ERGR, p-AKT and p-ERK. Further studies showed that EGFL7 knockdown or pharmacological inhibition of EGFR-pathway, using EGFR inhibitor Tyrphostin AG-1478, significantly suppressed migration and invasion of GH3 and GT1-1 cells. In summary, our findings suggest that EGFL7 is a key factor for regulation of EGFR signaling pathway and plays an important role in migration and invasion of invasive GHPA.