Nucleotide-binding domain of phosphoglycerate kinase 1 reduces tumor growth by suppressing COX-2 expression.

Department of Biotechnology and Laboratory Science in Medicine, National Yang-Ming University, Department of Education and Research, Taipei City Hospital, Taipei, Taiwan.
Cancer Science (Impact Factor: 3.53). 11/2010; 101(11):2411-6. DOI: 10.1111/j.1349-7006.2010.01691.x
Source: PubMed

ABSTRACT Phosphoglycerate kinase 1 (PGK-1) is a multifunctional protein that is involved in the glycolytic pathway and the generation of the angiogenesis inhibitor angiostatin. In a previous study, we showed that the overexpression of full-length PGK-1 in Lewis lung carcinoma (LLC-1) can reduce tumor growth in vivo by downregulation of COX-2 expression. Phosphoglycerate kinase 1 has two functional domains: a catalytic domain (CD); and a nucleotide-binding domain (NBD). To identify the functional domain of PGK-1 responsible for its antitumor effects, we evaluated the tumorigenicity of LLC-1 cells overexpressing full-length PGK-1 (LLC-1/PGK), CD (LLC-1/CD), and NBD (LLC-1/NBD). Although no difference in tumor cell growth was observed in vitro, the tumor invasiveness was reduced in the LLC-1/PGK, LLC-1/CD, and LLC-1/NBD cells compared to parental LLC-1 cells in vivo. In addition, in vivo tumor growth retardation by LLC-1/CD and LLC-1/NBD cells was observed, similar to that by LLC-1/PGK cells. However, the reduced stability of COX-2 mRNA and downregulation of the COX-2 protein and its metabolite, prostaglandin E2, was only found in LLC-1/PGK and LLC-1/NBD cells. Low levels of COX-2 were also observed in the tumor mass formed by the modified cells when injected into mice. The results indicate that COX-2 suppression by PGK-1 is independent of its catalytic activity. COX-2 targeting by PGK-1 can be attributed to its NBD and is probably a result of the destabilization of COX-2 gene transcripts brought about by the mRNA-binding property of PGK-1.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Mitosis is a fundamental process in the development of all organisms. The mitotic spindle guides the cell through mitosis as it mediates the segregation of chromosomes, the orientation of the cleavage furrow, and the progression of cell division. Birth defects and tissue-specific cancers often result from abnormalities in mitotic events. Here, we report a proteomic study of the mitotic spindle from Chinese Hamster Ovary (CHO) cells. Four different isolations of metaphase spindles were subjected to Multi-dimensional Protein Identification Technology (MudPIT) analysis and tandem mass spectrometry. We identified 1155 proteins and used Gene Ontology (GO) analysis to categorize proteins into cellular component groups. We then compared our data to the previously published CHO midbody proteome and identified proteins that are unique to the CHO spindle. Our data represent the first mitotic spindle proteome in CHO cells, which augments the list of mitotic spindle components from mammalian cells.
    PLoS ONE 05/2011; 6(5):e20489. · 3.53 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Activation of Toll-like receptor 4 (TLR4) triggers the innate immune response and leads to the induction of adaptive immunity. TLR4 agonists are known to function as immunostimulants and exhibit promising therapeutic potential for cancer immunotherapy. We have previously developed a synthetic serine-based glycolipid (designated as CCL-34) that can activate TLR4-dependent signaling pathways. In this study, the anticancer immunity of CCL-34 was further demonstrated. CCL-34-activated macrophages induced cancer cell death via the apoptotic pathway, and this cytotoxicity was significantly inhibited by NG-monomethyl-L-arginine (an inducible NOS inhibitor). Notably, conditioned medium collected from CCL-34-treated splenocytes also induced cytotoxicity toward cancer cells. Furthermore, CCL-34 treatment suppressed tumor growth and increased the survival rate in TLR4-functional C3H/HeN mice but not in TLR4-defective C3H/HeJ mice. Increased apoptosis, the induction of cytokines (IFN-γ and IL-12) and chemokines (CXCL9 and CXCL10), and the elevation of leukocyte markers (CD11b, CD11c, CD4, and CD8) were detected at tumor sites in C3H/HeN mice but not in C3H/HeJ mice. Structure-and-activity relationship analysis of CCL-34 and its structural analogs revealed that a sugar moiety is essential for its activity. However, the substitution of the galactose in CCL-34 with glucose or fucose did not reduce its activity. Altogether, this study reveals the anticancer activity of a new synthetic TLR4 agonist and broadens the molecular basis of TLR4-activating glycolipids.
    Journal of Biological Chemistry 09/2011; 286(51):43782-92. · 4.60 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Antibody-based immunotherapy has been effectively used for tumor treatment. However, to date, only a few tumor-associated antigens (TAAs) or therapeutic targets have been identified. Identification of more immunogenic antigens is essential for improvements in multiple myeloma (MM) diagnosis and therapy. In this study, we synthesized a polyclonal antibody (PAb) by immunizing rabbits with whole human plasmacytoma ARH-77 cells and identified MM-associated antigens, including enlonase, adipophilin, and HSP90s, among others, via proteomic technologies. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay showed that 200 µg/mL PAb inhibits the proliferation of ARH-77 cells by over 50% within 48 h. Flow cytometric assay indicated that PAb treatment significantly increases the number of apoptotic cells compared with other treatments (52.1% vs. NS, 7.3% or control rabbit IgG, 9.9%). In vivo, PAb delayed tumor growth and prolonged the lifespan of mice. Terminal deoxynucleotidyl transferase dUTP nick end labeling assay showed that PAb also induces statistically significant changes in apoptosis compared with other treatments (P<0.05). We therefore conclude that PAb could be used for the effective screening and identification of TAA. PAb may have certain anti-tumor functions in vitro and in vivo. As such, its combination with proteomic technologies could be a promising approach for sieving TAA for the diagnosis and therapy of MM.
    PLoS ONE 04/2013; 8(4):e59117. · 3.53 Impact Factor

Full-text (2 Sources)

Available from
Jan 7, 2015