Transcriptional regulation of the IL-13Rα2 gene in human lung fibroblasts

Interleukin 13 receptor alpha 2 (IL13Rα2): Expression, signaling pathways and therapeutic applications in cancer

Interleukin 13 receptor alpha 2 (IL13Rα2) is increasingly recognized as a relevant player in cancer invasion and metastasis. Despite being initially considered a decoy receptor for dampening the levels of interleukin 13 (IL-13) in diverse inflammatory conditions, accumulating evidences in the last decades indicate the capacity of IL13Rα2 for mediating IL-13 signaling in cancer cells. The biological reasons behind the expression of this receptor with such extremely high affinity for IL-13 in cancer cells remain unclear. Elevated expression of IL13Rα2 is commonly associated with invasion, late stage and cancer metastasis that results in poor prognosis for glioblastoma, colorectal or breast cancer, among others. The discovery of new mediators and effectors of IL13Rα2 signaling has been critical for deciphering its underlying molecular mechanisms in cancer progression. Still, many questions about the effects of inflammation, the cancer type and the tumor degree in the expression of IL13Rα2 remain largely uncharacterized. Here, we review and discuss the current status of the IL13Rα2 biology in cancer, with particular emphasis in the role of inflammation-driven expression and the regulation of different signaling pathways. As IL13Rα2 implications in cancer continue to grow exponentially, we highlight new targeted therapies recently developed for glioblastoma, colorectal cancer and other IL13Rα2-positive tumors.

Modulation of IL-4/IL-13 cytokine signaling in the context of allergic disease

Aberrant activation of CD4 T_H2 cells and excessive production of T_H2 cytokines such as IL-4 and IL-13 have been implicated in the pathogenesis of allergic diseases. Generally, IL-4 and IL-13 utilize Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathways for induction of inflammatory gene expression and the effector functions associated with disease pathology in many allergic diseases. However, it is increasingly clear that JAK/STAT pathways activated by IL-4/IL-13 can themselves be modulated in the presence of other intracellular signaling programs, thereby changing the overall tone and/or magnitude of IL-4/IL-13 signaling. Apart from direct activation of the canonic JAK/STAT pathways, IL-4 and IL-13 also induce proinflammatory gene expression and effector functions through activation of additional signaling cascades. These alternative signaling cascades contribute to several specific aspects of IL-4/IL-13-associated cellular and molecular responses. A more complete understanding of IL-4/IL-13 signaling pathways, including the precise conditions under which noncanonic signaling pathways are activated, and the impact of these pathways on cellular- and host-level responses, will better allow us to design agents that target specific pathologic outcomes or tailor therapies for the treatment of uncommon disease endotypes.

Strategies Targeting Type 2 Inflammation: From Monoclonal Antibodies to JAK-Inhibitors

Bronchial asthma and its frequent comorbidity chronic rhinosinusitis (CRS), are characterized by an inflammatory process at lower and upper respiratory tract, with a variability in terms of clinical presentations (phenotypes) and distinct underpin pathophysiological mechanisms (endotypes). Based on the characteristics of inflammation, bronchial asthma can be distinguished into type 2 (eosinophilic) or nontype 2 (noneosinophilic) endotypes. In type 2 asthma endotype, the pathogenic mechanism is sustained by an inflammatory process driven by Th2 cells, type 2 innate lymphoid cells (ILC2) and type 2 cytokines, which include interleukin (IL)-4, IL-5, IL-9 and IL-13. The definition of asthma and chronic rhinusinusitis phenotype/endotype is crucial, taking into account the availability of novel biologic agents, such as monoclonal antibodies targeting the classical type 2 cytokines. Recently, new therapeutic strategies have been proposed and analyzed in preliminary clinical trials. Among them Janus kinase (JAK) inhibitors, now largely used for the treatment of other chronic inflammatory diseases such as rheumatoid arthritis and inflammatory bowel diseases, is receiving great relevance. The rationale of this strategy derives from the data that JAK is a tyrosine kinase involved in the signaling of T cell receptor and of several cytokines that play a role in allergic respiratory disease, such as IL-2, IL-4 and IL-9. In this review, we discuss whether treatment with biological agents and JAK inhibitors may be equally effective in controlling type 2 inflammatory process in both asthma and CRS.