Citation Details

Journal Article

PC-3M-luc-C6, PC-3M-luc, IVIS, Bioware, Prostate cancer, Bioluminescence

Frequent side effects of radical treatment modalities and the availability of novel diagnostics have raised the interest in focal therapies for localized prostate cancer. To improve the selectivity and therapeutic efficacy of such therapies, we developed a minimally invasive procedure, based on a novel polymeric photosensitizer prodrug sensitive to urokinase-like plasminogen activator (uPA). The compound is inactive in its prodrug form and accumulates passively at the tumor site by the enhanced permeability and retention effect. There, the prodrug is selectively converted to its photoactive form by uPA which is over-expressed by prostate cancer cells. Irradiation of the activated photosensitizer exerts a tumor-selective phototoxic effect. The prodrug alone (8 microM) showed no toxic effect on PC-3 cells, but upon irradiation the cell viability was reduced by 90%. In vivo, after systemic administration of the prodrug, PC-3 xenografts became selectively fluorescent. This is indicative of the prodrug accumulation in the tumor and selective local enzymatic activation. Qualitative analysis of the activated compound confirmed that the enzymatic cleavage occurred selectively in the tumor, with only trace amounts in the neighboring skin or muscle. Subsequent photodynamic therapy studies demonstrated complete tumor eradication of animals treated with light (150 J/cm2 at 665 nm) 16 hours after the injection of the prodrug (7.5 mg/kg). These promising results evidence the excellent selectivity of our prodrug with the potential to be used for both, imaging and therapy of localized prostate cancer.

Journal Article

PC-3M-luc-C6, PC-3M-luc, IVIS, Bioware, Prostate cancer, Bioluminescence, Animals; Base Sequence; Blotting, Western; Chromatin Immunoprecipitation; Clusterin/genetics/*physiology; DNA Primers; Epithelial-Mesenchymal Transition/*physiology; Humans; Male; Mice; *Neoplasm Metastasis; Nuclear Proteins/*physiology; Promoter Regions, Genetic; Prostatic Neoplasms/*pathology; Reverse Transcriptase Polymerase Chain Reaction; Transforming Growth Factor beta/*physiology; Twist Transcription Factor/*physiology

TGF-beta promotes epithelial-mesenchymal transition (EMT) and induces clusterin (CLU) expression, linking these genes to cancer metastasis. CLU is a pleiotropic molecular chaperone that confers survival and proliferative advantage to cancer cells. However, the molecular mechanisms by which TGF-beta regulates CLU expression and CLU affects metastasis remain unknown. In this study, we report that the transcription factor Twist1 mediates TGF-beta-induced CLU expression. By binding to E-boxes in the distal promoter region of CLU gene, Twist1 regulated basal and TGF-beta-induced CLU transcription. In addition, CLU reduction reduced TGF-beta induction of the mesenchymal markers, N-cadherin and fibronectin, thereby inhibiting the migratory and invasive properties induced by TGF-beta. Targeted inhibition of CLU also suppressed metastasis in an in vivo model. Taken together, our findings indicate that CLU is an important mediator of TGF-beta-induced EMT, and suggest that CLU suppression may represent a promising therapeutic option for suppressing prostate cancer metastatic progression.

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.

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

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.