Citation Details

Journal Article

IVIS, B16-F10-luc-G5, B16F10-luc-G5, B16-F10-luc, B16F10-luc, Carrier Proteins/genetics/*metabolism; Cell Line, Tumor; *Cell Movement; Gene Deletion; HEK293 Cells; Humans; Melanoma/genetics/*metabolism/pathology; Multiprotein Complexes/genetics/*metabolism; Neoplasm Invasiveness; Neoplasm Proteins/genetics/*metabolism; Proteins/genetics/*metabolism; RNA Polymerase II/genetics/metabolism

The Elongator complex is composed of 6 subunits (Elp1-Elp6) and promotes RNAPII transcript elongation through histone acetylation in the nucleus as well as tRNA modification in the cytoplasm. This acetyltransferase complex directly or indirectly regulates numerous biological processes ranging from exocytosis and resistance to heat shock in yeast to cell migration and neuronal differentiation in higher eukaryotes. The identity of human ELP1 through ELP4 has been reported but human ELP5 and ELP6 have remained uncharacterized. Here, we report that DERP6 (ELP5) and C3ORF75 (ELP6) encode these subunits of human Elongator. We further investigated the importance and function of these two subunits by a combination of biochemical analysis and cellular assays. Our results show that DERP6/ELP5 is required for the integrity of Elongator and directly connects ELP3 to ELP4. Importantly, the migration and tumorigenicity of melanoma-derived cells are significantly decreased upon Elongator depletion through ELP1 or ELP3. Strikingly, DERP6/ELP5 and C3ORF75/ELP6-depleted melanoma cells have similar defects, further supporting the idea that DERP6/ELP5 and C3ORF75/ELP6 are essential for Elongator function. Together, our data identify DERP6/ELP5 and C3ORF75/ELP6 as key players for migration, invasion and tumorigenicity of melanoma cells, as integral subunits of Elongator.

Journal Article

IVIS, B16-F10-luc-G5, B16F10-luc-G5, B16-F10-luc, B16F10-luc

Aim: The therapeutic potential of epigallocatechin-3-gallate (EGCG), a green tea polyphenol with anticancer properties, is limited by its inability to specifically reach tumors following intravenous administration. The purpose of this study was to determine whether a tumor-targeted vesicular formulation of EGCG would suppress the growth of A431 epidermoid carcinoma and B16-F10 melanoma in vitro and in vivo. Materials & methods: Transferrin-bearing vesicles encapsulating EGCG were administered intravenously to mice bearing subcutaneous A431 and B16-F10 tumors. Results: The intravenous administration of EGCG encapsulated in transferrin-bearing vesicles resulted in tumor suppression in 40% of A431 and B16-F10 tumors. Animal survival was improved by more than 20 days compared with controls. Conclusion: Encapsulation of EGCG in transferrin-bearing vesicles is a promising therapeutic strategy. Original submitted 28 November 2011; Revised submitted 11 May 2012.

Journal Article

IVIS, B16-F10-luc-G5, B16F10-luc-G5, B16-F10-luc, B16F10-luc, 14-3-3 Proteins/*genetics; Animals; Anticoagulants/pharmacology/*therapeutic use; Antineoplastic Agents/pharmacology/*therapeutic use; Apoptosis/drug effects; Cadherins/genetics; Cell Cycle/drug effects; Cell Line, Tumor; Cell Proliferation/*drug effects; Gene Expression Regulation, Neoplastic/drug effects; Heparin/pharmacology/*therapeutic use; Humans; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Metastasis/drug therapy/genetics; Neoplasms/*drug therapy/genetics; Prostate/drug effects/metabolism; Prostatic Neoplasms/drug therapy/genetics; Transforming Growth Factor beta/genetics; Vimentin/*genetics

AIM: To investigate the inhibitory effects of heparin on PC-3M cells proliferation in vitro and B16-F10-luc-G5 cells metastasis in Balb/c nude mice and identify the protein expression patterns to elucidate the action mechanism of heparin. METHODS: Human prostate cancer PC-3M cells were incubated with heparin 0.5 to 125 mug/mL for 24 h. The proliferation of PC-3M cells was assessed by MTS assay. BrdU incoporation and Ki67 expression were detected using a high content screening (HCS) assay. The cell cycle and apoptosis of PC-3M cells were tested by flow cytometry. B16-F10-luc-G5 cardinoma cells were injected into the lateral tail vein of 6-week old male Balb/c nude mice and heparin 30 mg/kg was administered iv 30 min before and 24 h after injection. The metasis of B16-F10-luc-G5 cells was detected by bioluminescence assay. Activated partial thromboplastin time (APTT) and hemorheological parameters were measured on d 14 after injection of B16-F10-luc-G5 carcinoma cells in Balb/c mice. The global protein changes in PC-3M cells and frozen lung tissues from mice burdened with B16-F10-luc-G5 cells were determined by 2-dimensional gel electrophoresis and image analysis. The protein expression of vimentin and 14-3-3 zeta/delta was measured by Western blot. The mRNA transcription of vimentin, transforming growth factor (TGF)-beta, E-cadherin, and alpha(v)-integrin was measured by RT-PCR. RESULTS: Heparin 25 and 125 mug/mL significantly inhibited the proliferation, arrested the cells in G(1) phase, and suppressed BrdU incorporation and Ki67 expression in PC-3M cells compared with the model group. But it had no significant effect on apoptosis of PC-3M cells. Heparin 30 mg/kg markedly inhibits the metastasis of B16-F10-luc-G5 cells on day 8. Additionally, heparin administration maintained relatively normal red blood hematocrit but had no influence on APTT in nude mice burdened with B16-F10-luc-G5 cells. Thirty of down-regulated protein spots were identified after heparin treatment, many of which are related to tumor development, extracellular signaling, energy metabolism, and cellular proliferation. Vimentin and 14-3-3 zeta/delta were identified in common in PC-3M cells and the lungs of mice bearing B16-F10-luc-G5 carcinoma cells. Heparin 25 and 125 mug/mL decreased the protein expression of vimentin and 14-3-3 zeta/delta and the mRNA expression of alpha(v)-integrin. Heparin 125 mug/mL decreased vimentin and E-cadherin mRNA transcription while increased TGF-beta mRNA transcription in the PC-3M cells, but the differences were not significant. Transfection of vimentin-targeted siRNA for 48 h significantly decreased the BrdU incoporation and Ki67 expression in PC-3M cells. CONCLUSION: Heparin inhibited PC-3M cell proliferation in vitro and B16-F10-luc-G5 cells metastasis in nude mice by inhibition of vimentin, 14-3-3 zeta/delta, and alpha(v)-integrin expression.

Journal Article

PC-3M-luc-C6, PC-3M-luc, IVIS, Bioware, Prostate cancer, Bioluminescence, Animals; Cell Line, Tumor; Endocytosis; Fluorescent Dyes/chemistry/*diagnostic use; Glucosamine/chemistry/*diagnostic use; Humans; Kinetics; Male; Mice; Mice, Nude; Molecular Imaging/*methods; Neoplasms/*diagnosis/pathology; Optical Devices; Prostatic Neoplasms/diagnosis/pathology; Spectroscopy, Near-Infrared; Tissue Distribution; *Xenograft Model Antitumor Assays

PURPOSE: Near-infrared fluorescence (NIRF) imaging is an attractive technique for studying diseases at the molecular level in vivo. Glucose transporters are often used as targets for in vivo imaging of tumors. The efficiency of a tumor-seeking fluorescent probe can be enhanced by attaching one or more glucosamine (GlcN) moieties. This study was designed to evaluate the use of previously developed GlcN-linked NIRF probes for in vitro and in vivo optical imaging of cancer. PROCEDURES: Cellular uptake of the probes (1 muM) was investigated in monolayer cultures of luciferase-expressing PC3 (PC3-luc) cells. The prostate tumors were established as subcutaneous xenografts using PC3-luc cells in nude mice. The biodistributions and tumor-targeting specificities of cypate (cyp), cypate-D: -(+)-glucosamine (cyp-GlcN), and D: -(+)-gluosamine-cypate-D: -(+)-gluosamine (cyp-2GlcN) were studied. The tumor, muscle, and major organs were collected for ex vivo optical imaging. RESULTS: The tumor cell uptake of the probe containing two glucosamine residues, cyp-2GlcN, was significantly higher than the uptake of both the probe with one glucosamine residue, cyp-GlcN, and the probe without glucosamine, cyp only. Similarly, in in vivo experiments, cyp-2GlcN demonstrated higher maximum fluorescence intensity and longer residence lifetime in tumors than cyp-GlcN or cyp. The ex vivo biodistribution analysis revealed that tumor uptake of cyp-2GlcN and cyp-GlcN was four- and twofold higher than that of cyp at 24 h post-injection, respectively. CONCLUSION: Both cyp-GlcN and cyp-2GlcN NIRF probes exhibited good tumor-targeting properties in prostate cancer cell cultures and live mice. The cyp-2GlcN probe showed the highest uptake with good retention characteristics in vivo. The uptake of cyp-2GlcN and cyp-GlcN is likely mediated by glucosamine-recognizing transporters. The uptake mechanism is being explored further for developing cypate-glucosamine-based probes for in vivo imaging.

Journal Article

PC-3M-luc-C6, PC-3M-luc, IVIS, Bioware, Prostate cancer, Bioluminescence, Animals; Chromatography, Liquid; Enzyme-Linked Immunosorbent Assay; Ephrins/genetics/*metabolism; Humans; Mass Spectrometry/*methods; Mice; Receptor, EphA1/genetics/*metabolism

The Eph receptor tyrosine kinase family includes many members, which are often expressed together in various combinations and can promiscuously interact with multiple ephrin ligands, generating intricate networks of intracellular signals that control physiological and pathological processes. Knowing the entire repertoire of Eph receptors and ephrins expressed in a biological sample is important when studying their biological roles. Moreover, given the correlation between Eph receptor/ephrin expression and cancer pathogenesis, their expression patterns could serve important diagnostic and prognostic purposes. However, profiling Eph receptor and ephrin expression has been challenging. Here we describe a novel and straightforward approach to catalog the Eph receptors present in cultured cells and tissues. By measuring the binding of ephrin Fc fusion proteins to Eph receptors in ELISA and pull-down assays, we determined that a mixture of four ephrins is suitable for isolating both EphA and EphB receptors in a single pull-down. We then used mass spectrometry to identify the Eph receptors present in the pull-downs and estimate their relative levels. This approach was validated in cultured human cancer cell lines, human tumor xenograft tissue grown in mice, and mouse brain tissue. The new mass spectrometry approach we have developed represents a useful tool for the identification of the spectrum of Eph receptors present in a biological sample and could also be extended to profiling ephrin expression.