Host IL11 Signaling Suppresses CD4+ T cell-Mediated Antitumor Responses to Colon Cancer in Mice.

IL11 is a member of the IL6 family of cytokines and signals through its cognate receptor subunits, IL11RA and glycoprotein 130 (GP130), to elicit biological responses via the JAK/STAT signaling pathway. IL11 contributes to cancer progression by promoting the survival and proliferation of cancer cells, but the potential immunomodulatory properties of IL11 signaling during tumor development have thus far remained unexplored. Here, we have characterized a role for IL11 in regulating CD4+ T cell-mediated antitumor responses. Absence of IL11 signaling impaired tumor growth in a sporadic mouse model of colon cancer and syngeneic allograft models of colon cancer. Adoptive bone marrow transfer experiments and in vivo depletion studies demonstrated that the tumor-promoting activity of IL11 was mediated through its suppressive effect on host CD4+ T cells in the tumor microenvironment. Indeed, when compared with Il11ra-proficient CD4+ T cells associated with MC38 tumors, their Il11ra-deficient counterparts displayed elevated expression of mRNA encoding the antitumor mediators IFNγ and TNFα. Likewise, IL11 potently suppressed the production of proinflammatory cytokines (IFNγ, TNFα, IL6, and IL12p70) by CD4+ T cells in vitro, which we corroborated by RNAscope analysis of human colorectal cancers, where IL11RAhigh tumors showed less IFNG and CD4 expression than IL11RAlow tumors. Therefore, our results ascribe a tumor cell-extrinsic immunomodulatory role to IL11 during colon cancer development that could be amenable to an anticytokine-based therapy.See related Spotlight by van der Burg, p. 724.

Interleukin-11 receptor alpha is expressed on canine osteosarcoma.

Osteosarcoma (OSA) is the most common bone tumour in humans and companion animals, and has a poor long-term prognosis. The identification of new markers and targeted therapies may help increase long-term survival of these patients. Previous studies have demonstrated that interleukin-11 receptor alpha (IL-11Ralpha) is expressed in human and murine OSA but not in normal bone. The current study demonstrated via western analysis, immunoflourescence and immunohistochemistry that IL-11Ralpha was expressed in primary canine OSA tissues as well as in a number of canine OSA cell lines, but not in normal canine bone. Cytotoxin-conjugated antibodies targeting IL-11Ralpha-mediated canine OSA cytotoxicity. Thus, canine OSA may be a valuable model for the evaluation of IL-11Ralpha directed therapies.

The interleukin-11 receptor alpha as a candidate ligand-directed target in osteosarcoma: consistent data from cell lines, orthotopic models, and human tumor samples.

The interleukin-11 receptor alpha (IL-11Ralpha) is a functional target in bone metastasis. However, its role in primary bone tumors has not been established. As such, here, we evaluated IL-11Ralpha as a candidate target in primary and metastatic human osteosarcoma. First, in an orthotopic mouse model, we showed that IL-11Ralpha protein is markedly expressed in primary osseus and pulmonary metastatic osteosarcoma but absent from control normal tibia and lung. Moreover, systemic administration of an IL-11Ralpha-targeting phage displaying the cyclic nonapeptide CGRRAGGSC resulted in strong and selective accumulation of IL-11Ralpha-homing phage particles in the osteosarcoma but not in several control organs. Finally, IL-11Ralpha expression in a large panel of human primary and metastatic osteosarcoma samples was remarkably consistent with the observations in the orthotopic mouse model. These data establish IL-11Ralpha as a candidate target in human osteosarcoma and provide leads for the development of novel imaging and therapeutic agents for the management of this malignant tumor.

Expression of interleukin-11 (IL-11) and IL-11 receptor alpha in human gastric carcinoma and IL-11 upregulates the invasive activity of human gastric carcinoma cells.

Previous investigations have shown that interleukin-11 (IL-11) and the IL-11 receptor (IL-11R) have been correlated with the regulation of tumor progression, cellular growth and differentiation in several malignant tumors. The objectives of this study were to clarify the role of IL-11 and IL-11Ralpha in human gastric carcinoma. IL-11 and IL-11Ralpha were studied in 73 cases of surgically resected human gastric adenocarcinomas by immunohistochemistry. The invasive activity and cell signaling pathway of gastric carcinoma cell lines were also examined. Among the 73 cases of adenocarcinoma, 53 (72.6%) and 47 cases (64.4%) showed positive staining in carcinoma cells for the IL-11 and IL-11Ralpha proteins, respectively. Histologically, IL-11 expression correlated only with Lauren's classification (p<0.05). The expression of IL-11Ralpha correlated with the grade of tumor invasion (p<0.05) and vessel infiltration (p<0.01). All of the four gastric carcinoma cell lines expressed both IL-11 and IL-11Ralpha proteins in western blot analysis. Recombinant human IL-11 (rhIL-11) promoted the migration of SCH cells by the activation of the phosphatidylinositol-3 kinase pathway. Wortmannin diminished the promotion of chemotactic motility and invasive activity by rhIL-11. These findings suggest that the IL-11/IL-11R pathway plays an important role in the progression and the differentiation of human gastric carcinomas.