MFGE8 promotes gastric cancer progression by activating the IL-6/JAK/ STAT3 signaling

Objective: Gastric cancer is malignant cancer with high morbidity and mortality worldwide. Milk fat globule EGF and factor V/VIII domain containing (MFGE8) was involved in many cancers. Nevertheless, the role of MFGE8 in gastric cancer remained indistinct. To probe the role of MFGE8 in gastric cancer and further explore the regulating mechanism. Methods: GEPIA was employed for analysis of MFGE8 expression and survival of gastric cancer patients. MFGE8 expression in gastric cancer was determined by immunohistochemistry, PCR, and western blot. The effect of MFGE8 on gastric cancer cells were evaluated by a series of cell function experiments. The mechanism of MFGE8 on gastric cancer was analyzed by GSEA and verified by in vitro and in vivo experiments. Results: MFGE8 was over-expressed in gastric cancer. Silence of MFGE8 suppressed cell viability, proliferated ability, migrated and invasive ability, and EMT, but accelerated cell apoptosis. The opposite results were obtained in MFGE8-overexpressed gastric cancer cells. Zinc finger and BTB domain containing 7 A (ZBTB7A) was a transcription factor of MFGE8. ZBTB7A overexpression eliminated the effect of MFGE8 on gastric cancer cells. MFGE8 activated the IL-6/JAK/STAT3 signaling. Inhibition of IL-6/JAK/STAT3 signaling by Stattic (pathway inhibitor) could eliminate the promoting effect of MFGE8 on IL-6/JAK/STAT3 signaling. In addition, MFGE8 shRNA inhibited tumor growth. Conclusion: MFGE8 promoted cell proliferation, EMT progress, and tumor growth of gastric cancer by activating the IL-6/JAK/STAT3 signaling.