Elevated IL-17 produced by TH17 cells promotes myeloma cell growth and inhibits immune function in multiple myeloma.

Elevated cytokines in bone marrow (BM) micro-environment (interleukin-6 [IL-6], transforming growth factor-beta [TGF-beta], and IL-1beta) may play an important role in observed immune dysfunction in multiple myeloma (MM). As IL-6 and TGF-beta are important for the generation of T-helper 17 (T(H)17) cells, we evaluated and observed a significantly elevated baseline and induced frequency of T(h)17 cells in peripheral blood mononuclear cells (PBMCs) and BM mononuclear cells (BMMCs) from MM patients compared with healthy donors. We observed significant increase in levels of serum IL-17, IL-21, IL-22, and IL-23 in blood and BM in MM compared with healthy donors. We also observed that myeloma PBMCs after T(H)17 polarization significantly induced IL-1alpha, IL-13, IL-17, and IL-23 production compared with healthy donor PBMCs. We next observed that IL-17 promotes myeloma cell growth and colony formation via IL-17 receptor, adhesion to bone marrow stromal cells (BMSCs) as well as increased growth in vivo in murine xenograft model of human MM. Additionally, we have observed that combination of IL-17 and IL-22 significantly inhibited the production of T(H)1-mediated cytokines, including interferon-gamma (IFN-gamma), by healthy donor PBMCs. In conclusion, IL-17-producing T(h)17 cells play an important role in MM pathobiology and may be an important therapeutic target for anti-MM activity and to improve immune function.

An RNAi therapeutic targeting antithrombin to rebalance the coagulation system and promote hemostasis in hemophilia.

Hemophilia A and B are inherited bleeding disorders characterized by deficiencies in procoagulant factor VIII (FVIII) or factor IX (FIX), respectively. There remains a substantial unmet medical need in hemophilia, especially in patients with inhibitory antibodies against replacement factor therapy, for novel and improved therapeutic agents that can be used prophylactically to provide effective hemostasis. Guided by reports suggesting that co-inheritance of prothrombotic mutations may ameliorate the clinical phenotype in hemophilia, we developed an RNA interference (RNAi) therapeutic (ALN-AT3) targeting antithrombin (AT) as a means to promote hemostasis in hemophilia. When administered subcutaneously, ALN-AT3 showed potent, dose-dependent, and durable reduction of AT levels in wild-type mice, mice with hemophilia A, and nonhuman primates (NHPs). In NHPs, a 50% reduction in AT levels was achieved with weekly dosing at approximately 0.125 mg/kg, and a near-complete reduction in AT levels was achieved with weekly dosing at 1.5 mg/kg. Treatment with ALN-AT3 promoted hemostasis in mouse models of hemophilia and led to improved thrombin generation in an NHP model of hemophilia A with anti-factor VIII inhibitors. This investigational compound is currently in phase 1 clinical testing in subjects with hemophilia A or B.

miR-9, a MYC/MYCN-activated microRNA, regulates E-cadherin and cancer metastasis.

MicroRNAs (miRNAs) are increasingly implicated in regulating the malignant progression of cancer. Here we show that miR-9, which is upregulated in breast cancer cells, directly targets CDH1, the E-cadherin-encoding messenger RNA, leading to increased cell motility and invasiveness. miR-9-mediated E-cadherin downregulation results in the activation of beta-catenin signalling, which contributes to upregulated expression of the gene encoding vascular endothelial growth factor (VEGF); this leads, in turn, to increased tumour angiogenesis. Overexpression of miR-9 in otherwise non-metastatic breast tumour cells enables these cells to form pulmonary micrometastases in mice. Conversely, inhibiting miR-9 by using a 'miRNA sponge' in highly malignant cells inhibits metastasis formation. Expression of miR-9 is activated by MYC and MYCN, both of which directly bind to the mir-9-3 locus. Significantly, in human cancers, miR-9 levels correlate with MYCN amplification, tumour grade and metastatic status. These findings uncover a regulatory and signalling pathway involving a metastasis-promoting miRNA that is predicted to directly target expression of the key metastasis-suppressing protein E-cadherin.