IL-11 Promotes Tumor Progression And Correlates With Poor Prognosis In Non-small Cell Lung Cancer

Objective: To investigate the role of IL-11 in the progression of non-small-cell carcinoma(NSCLC)and explore related mechanisms.Methods:(1)Building A549 and H1299 cell lines with knockdown and overexpression of IL-11 and the effects of knocking down IL-11 on cell proliferation were analyzed by colony formation,proliferation curve and Brd U incorporation assay;The change of cell proliferation ability after blocking IL-11 was analyzed by addition of Ig G or IL-11 neutralizing antibody.(2)A549 cells treated with scramble or sh IL11-1 were injected into the right flank of female nude mice to investigate the effect of IL-11 on tumorigenesis in vivo.(3)In A549 and H1299 cell lines with knockdown or overexpression IL-11,the effects of IL-11 on migration and invasion were analyzed by migration assay and invasion assay;The change of cell migration and invasion ability after blocking IL-11 was analyzed by addition of Ig G or IL-11 neutralizing antibody.(4)A549 cells treated with scramble or sh IL11-1 were injected into the tail vein of nude mice to observe lung metastases and life span of mice.(5)Immunofluorescence assay was used to detect the change of EMT markers in A549 cell line with knocked down IL-11;In A549 and H1299 cell lines with knocked down IL-11,Western blotting was used to detect the expression level of EMT markers;The effect of IL-11 on EMT marker expression also was analyzed by addition of Ig G or IL-11 neutralizing antibody.(6)In A549 and H1299 cell lines with knocked down IL-11,using Western blotting to detect whether IL-11 participates in STAT3 and AKT signaling pathway.(7)To investigate the expression of HIF-1? and IL-11 in NSCLC under normoxia or hypoxia condition and detect the expression of IL-11 after adding HIF-1? blockers in normoxia condition.(8)The expression levels of IL-11 in 18 NSCLC patients and 5 normal lung samples were analyzed by q RT-PCR and the correlation between the high level of IL-11 and patient's prognosis was analyzed in the published data of online databases.Results:(1)A549 and H1299 cells with knockdown or overexpression of IL-11 were successfully builded;IL-11 can promote NSCLC cells proliferation and enhanced proliferation ability was reversed by IL-11 neutralizing antibodies.(2)In the mouse subcutaneous tumor formation experiment,the mice injected with IL-11 cells knocked down the ability of subcutaneous tumorigenesis significantly decreased compared with the mice injected with the control cells.(3)IL-11 can promote cell migration and invasion,while the ability of IL-11 induced enhanced migration and invasion was reversed by IL-11 neutralizing antibodies.(4)In the mouse lung metastasis model,conpared with control group,survival time and the lung metastasis ability of mice injected with IL-11-knockdown cells was significantly reduced.(5)Suppression of IL-11 induced expression of epithelial makers and downregulated mesenchymal markers.meanwhile,overexpression of IL-11 reversed the effects.(6)IL-11 can activate STAT3 and AKT signaling pathways in NSCLC;Compared with the control group,suppression of IL-11 can inhibit STAT3 expression in subcutaneous xenograft tumors of mouse.(7)Compared with normoxic condition,the expression level of HIF-1? and IL-11 was significantly increased under hypoxia condition in NSCLC cells.In normoxic condition,the expression of IL-11 was significantly increased after adding HIF-1? blocker,suggesting hypoxia can induce IL-11 expression by HIF-1? in cells.(8)Upregulation of IL-11 expression was observed in NSCLC samples compared with normal tissue samples.Public data from online indicate that high expression of IL-11 correlates with poor prognosis.Conclusion: Our results show that IL-11 can promote proliferation,migration and invasion of NSCLC cells;IL-11 participates in hypoxia response and EMT.Furthermore,IL-11 is up-regulated and associated with poor prognosis in NSCLC patients.