LncRNAs are involved in the initiation and progression of cancer. However, the molecular mechanism and diverse clinical prognosis of MIR31HG in head and neck squamous cell carcinoma (HNSCC) are still unclear. Our previous microarray analysis showed that lncRNA MIR31HG interacted with HIF1A may play an oncogenic role in laryngeal squamous cell cancer (LSCC). To determine whether lncRNA MIR31HG served as a poor prognosis factor and targeted HIF1A to facilitate cell proliferation and tumorigenesis in human HNSCC, we found MIR31HG and HIF1A were overexpressed in LSCC, MIR31HG overexpression or co-expression of HIF1A-positive and p21-negative could serve as a poor prognostic factor for LSCC patients. We further confirmed that MIR31HG promoted cell proliferation, cell cycle progression, and inhibited cell apoptosis in vitro and in vivo. The ingenuity pathway analysis and Western blot indicated that MIR31HG regulated cell cycle progression via HIF1A and p21 in HNSCC. The current results provide evidences for the role of MIR31HG in promoting HNSCC progression and identify MIR31HG as a prognostic biomarker and putative therapeutic target in HNSCC.Electronic supplementary materialThe online version of this article (10.1186/s12943-018-0916-8) contains supplementary material, which is available to authorized users.

Insulin and adrenergic stimulation are two divergent regulatory systems that may interact under certain pathophysiological circumstances. Here, we characterized a complex consisting of insulin receptor (IR) and β2-adrenergic receptor (β2AR) in the heart. The IR/β2AR complex undergoes dynamic dissociation under diverse conditions such as Langendorff perfusions of hearts with insulin or after euglycemic-hyperinsulinemic clamps in vivo. Activation of IR with insulin induces protein kinase A (PKA) and G-protein receptor kinase 2 (GRK2) phosphorylation of the β2AR, which promotes β2AR coupling to the inhibitory G-protein, Gi. The insulin-induced phosphorylation of β2AR is dependent on IRS1 and IRS2. After insulin pretreatment, the activated β2AR-Gi signaling effectively attenuates cAMP/PKA activity after β-adrenergic stimulation in cardiomyocytes and consequently inhibits PKA phosphorylation of phospholamban and contractile responses in myocytes in vitro and in Langendorff perfused hearts. These data indicate that increased IR signaling, as occurs in hyperinsulinemic states, may directly impair βAR-regulated cardiac contractility. This β2AR-dependent IR and βAR signaling cross-talk offers a molecular basis for the broad interaction between these signaling cascades in the heart and other tissues or organs that may contribute to the pathophysiology of metabolic and cardiovascular dysfunction in insulin-resistant states.

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