Recombinant Human IL-11 Promotes Lung Adenocarcinoma A549 Cell Growth and EMT through Activating STAT3/HIF-1α/EMT Signaling Pathway

Background: Interleukin-11 (IL-11) could promote invasion and metastasis of cancer cells, however, its mechanism is unclear. Objective: This study aimed to investigate the effects of recombinant human IL-11 (rhIL-11) on lung cancer cell metastasis and growth. Methods: Human lung cancer cell, A549, was cultured and subcutaneously injected into mice to establish Xenograft tumor models. Tumor models were divided into control, rhIL-11 transplantation (250 mu g/kg/day), and rhIL-11 transplantation (500 mu g/kg/day) group. Tumor volumes were recorded and measured 6 times. Hypoxia-Inducible Factor 1 alpha (HIF1 alpha), snail, slug, Signal Transducers/Activators of Transcription-3 (STAT3), E-cadherin, twist, and vimentin levels were evaluated using western blot and Real-Time PCR (RT-PCR). Results: Sizes of subcutaneous tumors increased following measurement time. rhIL-11 treatment significantly enhanced HIF1 alpha and STAT3 expression in rhIL-11 treatment groups compared to the control group (p<0.05). However, no remarkable differences were discovered between rhIL-11 (250 mu g/kg/day) and rhIL-11 (500 mu g/kg/day) group (p>0.05). rhIL-11 treatments significantly increased twist, and slug expressions compared to control group (p<0.05), especially for rhIL-11 (500 mu g/kg/day) treatment, which triggered significantly higher effects on twist and slug expressions compared to those in the control group (p<0.05). Vimentin and snail mRNA levels were significantly up-regulated and E-cadherin level was significantly down-regulated in rhIL-11 treatment groups compared to the control group (p<0.05). Meanwhile, rhIL-11 at a dosage of 500 mu g/kg/day triggered remarkably higher effects on vimentin, snail, and E-cadherin expressions compared to those in rhIL-11 (250 mu g/kg/day) group (p<0.05). Conclusion: rhIL-11 transplantation promoted growth and Epithelial-Mesenchymal Transition (EMT) of A549 cells, which might be associated with STAT3/HIF-1 alpha/EMT signaling pathway activation.