A TNFR1-UBCH10 axis drives lung squamous cell carcinoma dedifferentiation and metastasis through a cell-autonomous signaling loop.

Tumor necrosis factor receptor 1 (TNFR1), encoded by TNFRSF1A, is a critical transducer of inflammatory pathways, but its physiological role in human cancer is not completely understood. Here, we observed high expression of TNFR1 in many human lung squamous cell carcinoma (SCCs) samples and in spontaneous lung SCCs derived from kinase-dead Ikkα knock-in (KA/KA) mice. Knocking out Tnfrf1a in KA/KA mice blocked lung SCC formation.

Human Domain Antibodies to Conserved Epitopes on HER2 Potently Inhibit Growth of HER2-Overexpressing Human Breast Cancer Cells In Vitro.

The FDA approval of two anti-HER2 monoclonal antibodies, trastuzumab and pertuzumab, and an antibody-drug conjugate, trastuzumab emtansine, has transformed clinical practice for HER2-positive cancers. However, not all patients respond to therapy, and the majority of responders eventually develop resistance. In addition, cardiotoxicity is a major safety concern for their clinical use.

An IKKα-nucleophosmin axis utilizes inflammatory signaling to promote genome integrity.

The inflammatory microenvironment promotes skin tumorigenesis. However, the mechanisms by which cells protect themselves from inflammatory signals are unknown. Downregulation of IKKα promotes skin tumor progression from papillomas to squamous cell carcinomas, which is frequently accompanied by genomic instability, including aneuploid chromosomes and extra centrosomes.

The pivotal role of IKKα in the development of spontaneous lung squamous cell carcinomas.

Here, we report that kinase-dead IKKα knockin mice develop spontaneous lung squamous cell carcinomas (SCCs) associated with IKKα downregulation and marked pulmonary inflammation. IKKα reduction upregulated the expression of p63, Trim29, and keratin 5 (K5), which serve as diagnostic markers for human lung SCCs. IKKα(low)K5(+)p63(hi) cell expansion and SCC formation were accompanied by inflammation-associated deregulation of oncogenes, tumor suppressors, and stem cell regulators.

Inhibition of Fas ligand in NOD mice unmasks a protective role for IL-10 against insulitis development.

Type 1 diabetes mellitus (T1D) is an autoimmune disease caused by the destruction of pancreatic insulin-producing β cells by autoreactive T cells early in life. Despite daily insulin injections, patients typically develop cardiovascular and other complications; and intensive efforts are being directed toward identifying therapeutic targets to prevent the disease without directly impinging on the host defense. Fas ligand (FasL) is one potential target.

Toll-like receptor 9 is required for opioid-induced microglia apoptosis.

Opioids have been widely applied in clinics as one of the most potent pain relievers for centuries, but their abuse has deleterious physiological effects beyond addiction. However, the underlying mechanism by which microglia in response to opioids remains largely unknown. Here we show that morphine induces the expression of Toll-like receptor 9 (TLR9), a key mediator of innate immunity and inflammation.

Blocking Fas ligand on leukocytes attenuates kidney ischemia-reperfusion injury.

Inflammation contributes to the pathogenesis of ischemic acute kidney injury (AKI), and T cells mediate the early phase of ischemia-reperfusion injury (IRI). The Fas/Fas ligand (FasL) pathway modulates the balance of T cell subsets in the peripheral circulation as well as multiple inflammatory responses, suggesting that FasL may mediate ischemic AKI. Here, we induced bilateral renal IRI in mice bearing a loss-of-function mutation of FasL (the gld mutation) and in wild-type mice.

Regulation of Hsp90 client proteins by a Cullin5-RING E3 ubiquitin ligase.

We report a link between Cullin5 (Cul5) E3 ubiquitin ligase and the heat shock protein 90 (Hsp90) chaperone complex. Hsp90 participates in the folding of its client proteins into their functional conformation. Many Hsp90 clients have been reported to be aberrantly expressed in a number of cancers.

Fas-mediated apoptosis regulates the composition of peripheral alphabeta T cell repertoire by constitutively purging out double negative T cells.

Background: The Fas pathway is a major regulator of T cell homeostasis, however, the T cell population that is controlled by the Fas pathway in vivo is poorly defined. Although CD4 and CD8 single positive (SP) T cells are the two major T cell subsets in the periphery of wild type mice, the repertoire of mice bearing loss-of-function mutation in either Fas (lpr mice) or Fas ligand (gld mice) is predominated by CD4(-)CD8(-) double negative alphabeta T cells that also express B220 and generally referred to as B220+DN T cells. Despite extensive analysis, the basis of B220+DN T cell lymphoproliferation remains poorly understood.

Structural insight into the human immunodeficiency virus Vif SOCS box and its role in human E3 ubiquitin ligase assembly.

Human immunodeficiency virus (HIV) virion infectivity factor (Vif) causes the proteasome-mediated destruction of human antiviral protein APOBEC3G by tethering it to a cellular E3 ubiquitin ligase composed of ElonginB, ElonginC, Cullin5, and Rbx2. It has been proposed that HIV Vif hijacks the E3 ligase through two regions within its C-terminal domain: a BC box region that interacts with ElonginC and a novel zinc finger motif that interacts with Cullin5. We have determined the crystal structure of the HIV Vif BC box in complex with human ElonginB and ElonginC.

Characterization of a novel Cullin5 binding domain in HIV-1 Vif.

Human immunodeficiency virus tyoe 1 (HIV-1) Vif counteracts host restriction cytidine deaminase (APOBEC3G) A3G by co-opting the cellular ubiquitin-proteasome machinery. Vif utilizes a viral-specific BC-box to recruit ElonginB-ElonginC and a novel zinc-binding HCCH motif to recruit Cullin5 (Cul5) to form an E3 ubiquitin ligase targeting A3G for polyubiquitination and subsequently proteasomal degradation. To determine the structural requirements in HIV-1 Vif HCCH motif for Cul5 binding and Vif function, we investigated the arrangement of the His and Cys residues, the role of the spacing between them, and the requirement for the conserved residues.

Protection from autoimmune diabetes and T-cell lymphoproliferation induced by FasL mutation are differentially regulated and can be uncoupled pharmacologically.

Spontaneous mutation of Fas (lpr) or FasL (gld) completely protects nonobese diabetic mice from autoimmune diabetes but also causes massive double-negative T-cell lymphoproliferation. In this study, we used bone marrow chimeras and adoptive transfer analysis to investigate further the role of FasL in the pathogenesis of autoimmune diabetes and to determine whether gld-induced tolerance and double-negative T-cell lymphoproliferation can be uncoupled from each other. We show that FasL expressed on hematopoietic and nonhematopoietic compartments plays nonredundant roles in the pathogenesis of autoimmune diabetes.

Cytidine deaminases APOBEC3G and APOBEC3F interact with human immunodeficiency virus type 1 integrase and inhibit proviral DNA formation.

APOBEC3G (A3G) is a single-stranded DNA cytidine deaminase that targets retroviral minus-strand DNA and has potent antiviral activity against diverse retroviruses. However, the mechanisms of A3G antiviral functions are incompletely understood. Here we demonstrate that A3G, A3F, and, to a lesser extent, the noncatalytic A3GC291S block human immunodeficiency virus type 1 (HIV-1) replication by interfering with proviral DNA formation.

Adenovirus E4orf6 assembles with Cullin5-ElonginB-ElonginC E3 ubiquitin ligase through an HIV/SIV Vif-like BC-box to regulate p53.

The adenovirus protein E4orf6 targets p53 for polyubiquitination and proteasomal degradation and is known to form a complex with the Cul5-ElonginB-ElonginC E3 ubiquitin ligase. However, whether Cul5 is directly responsible for the E4orf6-mediated degradation of p53 remains unclear. By using a dominant-negative mutant of Cul5 and silencing Cul5 expression through RNA interference, we have now demonstrated that E4orf6-mediated p53 degradation requires Cul5.

Zinc chelation inhibits HIV Vif activity and liberates antiviral function of the cytidine deaminase APOBEC3G.

APOBEC3 proteins are cellular antiviral proteins that are targeted for proteasomal degradation by primate lentiviral Vif proteins. Vif acts as a substrate receptor for the Cullin5 (Cul5) E3 ubiquitin ligase, specifically interacting with Cul5 through a novel H-(x5)-C-(x17-18)-C-(x3-5)-H zinc binding motif. Using the membrane-permeable zinc chelator, N,N,N',N'-tetrakis-(2-pyridylmethyl) ethylenediamine (TPEN), we demonstrated a requirement for zinc for Vif function in vivo.

Assembly of HIV-1 Vif-Cul5 E3 ubiquitin ligase through a novel zinc-binding domain-stabilized hydrophobic interface in Vif.

APOBEC3G (A3G) and related cytidine deaminases are potent inhibitors of retroviruses. HIV-1 Vif hijacks the cellular Cul5-E3 ubiquitin ligase to degrade APOBEC3 proteins and render them ineffective against these viruses. Here, we report that HIV-1 Vif is a novel zinc-binding protein containing an H-x(5)-C-x(17-18)-C-x(3-5)-H motif that is distinct from other recognized classes of zinc fingers.

Primate lentiviral virion infectivity factors are substrate receptors that assemble with cullin 5-E3 ligase through a HCCH motif to suppress APOBEC3G.

Cullin-Ring E3 ubiquitin ligases target substrates for ubiquitin-dependent, proteasome-mediated degradation and regulate critical cellular processes. These cullins assemble with cellular substrate receptor proteins through specific adaptor molecules. F-box- and BC-box-containing receptors use Skp1, ElonginB, and ElonginC as adaptors to recruit Cul1/Cul7 and Cul2/Cul5, respectively.

Selective assembly of HIV-1 Vif-Cul5-ElonginB-ElonginC E3 ubiquitin ligase complex through a novel SOCS box and upstream cysteines.

APOBEC3G, which induces hypermutations in newly synthesized viral DNA, is suppressed by HIV-1 Vif, acting through Cul5-ElonginB-ElonginC E3 ubiquitin ligase. We have now characterized a novel SOCS box in HIV-1 Vif that mediates its interaction with ElonginC. In this SOCS box, alanine replaces the consensus cysteine in the previously identified SOCS box.

Amino-terminal region of the human immunodeficiency virus type 1 nucleocapsid is required for human APOBEC3G packaging.

APOBEC3G exerts its antiviral activity by targeting to retroviral particles and inducing viral DNA hypermutations in the absence of Vif. However, the mechanism by which APOBEC3G is packaged into virions remains unclear. We now report that viral genomic RNA enhances but is not essential for human APOBEC3G packaging into human immunodeficiency virus type 1 (HIV-1) virions.

Clinical significance of vascular endothelial growth factor expression and neovascularization in colorectal carcinoma.

Aim: To clarify the association of vascular endothelial growth factor (VEGF) and microvascular density (MVD) expression with the angiogenesis and prognosis of colorectal cancer.

Methods: A total of 97 cases of colorectal carcinomas were examined by immunohistochemical staining (SP method), using anti-VEGF and anti-factor CD34(+) monoclonal antibodies.

Results: VEGF positive staining was obtained in 68 out of 97 cases (70.

[Subcutaneous transplantation of microencapsulated Chinese hamster ovary (CHO) cells/pcDNA 3.1/mIL-12 and subcutaneous transplantation of microencapsulated CHO/pcDNA3.1/mIL-12 combined with 5-fluoro-uracil in treatment of tumor-burdened mice].

Objective: To investigate the effect of subcutaneous transplantation of microencapsulated Chinese hamster ovary cells (CHO)/pcDNA3.1/mIL-12 and subcutaneous transplantation of microencapsulated CHO/pcDNA3.1/mIL-12 combined with 5-fluoro-uracilum (5-FU) in treatment of tumor-burdened mice.

Continuous release of interleukin 12 from microencapsulated engineered cells for colon cancer therapy.

Aim: To explore the anti-tumor immunity against CT26 colon tumor of the microencapsulated cells modified with murine interleukine-12 (mIL-12) gene.

Methods: Mouse fibroblasts (NIH3T3) were stably transfected to express mIL-12 using expression plasmids carrying mIL-12 gene (p35 and p40), and NIH3T3-mIL-12 cells were encapsulated in alginate microcapsules for long-term delivery of mIL-12. mIL-12 released from the microencapsulated NIH3T3-mIL-12 cells was confirmed using ELISA assay.

Inducible nitric oxide synthase expression is related to angiogenesis, bcl-2 and cell proliferation in hepatocellular carcinoma.

In this study, we examined the expression of inducible nitric oxide synthase (iNOS) and vascular endothelial growth factor (VEGF) by immunohistochemical staining in 76 tissue sections collected from hepatocellular carcinoma (HCC) patients undergoing hepatectomy. Microvascular density (MVD) was determined by counting endothelial cells immunostained using anti-CD34 antibody. We performed DNA-flow cytometric analyses to elucidate the impact of iNOS and VEGF expression on the cell cycle of HCC.