Dataset Information

CLDN3 in prostate cancer exosomes

ABSTRACT: Exosomes are an emerging source for biomarkers in various diseases. Prostate cancer is the most frequent cancer in men in industrialized countries. The only biomarker widely used is prostate specific antigen with its clinical relevance suffering from low specificity. To identify novel biomarker candidates for prostate cancer we isolated exosomes from the supernatant of malignant PC3 and benign PNT1A cells, grown under standard culture conditions, using sequential centrifugation and ultracentrifugation. Not to alter the cellular growth conditions an FBS-containing medium was used. As control this medium was also subjected to exosomen isolation. Exosome and control samples were analyzed on an LTQ-Orbitrap XL mass spectrometer and subsequently between 441 and 843 proteins per sample were identified by searching against the SwissProt database. 64 proteins exclusively found in PC3 exosomes were subjected to a scoring system, integrating data from five publicly accessible databases and literature search, to identify potential biomarker candidates. Among these the epithelial tight junction protein claudin-3 achieved the highest score. Retests under serum-free conditions using immunoblotting and immunogold-labeling confirmed the expression of claudin-3 on PC3 exosomes. Levels of circulating claudin-3 directly determined from blood plasma, without prior isolation of exosomes, using ELISA were significantly higher (p=0,038) in metastatic prostate cancer patients (n=15) compared to controls with histologically proven benign prostate hyperplasia (n=15). Our results for the first time describe claudin-3 as a potential biomarker candidate in prostate cancer, easily detectably using liquid biopsies, without need for laborious isolation of exosomes. Further studies including larger patient cohorts in different clinical states of prostate cancer are needed to validate our findings.

INSTRUMENT(S): LTQ Orbitrap

ORGANISM(S): Homo Sapiens (human) Bos Taurus (bovine)

TISSUE(S): Prostate Adenocarcinoma Cell Line, Prostate Epithelium Cell Line, Epithelial Cell, Blood Serum

DISEASE(S): Prostate Adenocarcinoma

SUBMITTER: Thomas Worst

LAB HEAD: Michael Boutros

PROVIDER: PXD003651 | Pride | 2017-04-13

REPOSITORIES: Pride

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Publications

Database-augmented Mass Spectrometry Analysis of Exosomes Identifies Claudin 3 as a Putative Prostate Cancer Biomarker.

Worst Thomas Stefan TS von Hardenberg Jost J Gross Julia Christina JC Erben Philipp P Schnölzer Martina M Hausser Ingrid I Bugert Peter P Michel Maurice Stephan MS Boutros Michael M

Molecular & cellular proteomics : MCP 20170409 6

In prostate cancer and other malignancies sensitive and robust biomarkers are lacking or have relevant limitations. Prostate specific antigen (PSA), the only biomarker widely used in prostate cancer, is suffering from low specificity. Exosomes offer new perspectives in the discovery of blood-based biomarkers. Here we present a proof-of principle study for a proteomics-based identification pipeline, implementing existing data sources, to exemplarily identify exosome-based biomarker candidates in ...[more]

PMID: 28396511

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Project description:Background: Aldo-keto reductase (AKR) 1C family member 3 (AKR1C3), one of four identified human AKR enzymes, catalyzes steroid, prostaglandin, and xenobiotic metabolism. In the prostate, AKR1C3 is up-regulated in localized and advanced prostate adenocarcinoma, and is associated with prostate cancer (PCa) aggressiveness. Here we provide initial evidence for potential roles of AKR1C3 in PCa progression. Methods: Spatial distribution of AKR1C3 was analyzed using immunohistochemical staining in prostate adenocarcinoma tissue array. Human PCa PC-3 cells were stably transfected with AKR1C3 cDNA to establish PC3-AKR1C3 transfectants. Microarray and bioinformatics analyses were performed to identify pathways that are activated by elevated AKR1C3 expression in PCa cells. Functional confirmation of microarray and bioinformatics results was performed by immunoblot analysis and an in vitro Matrigel angiogenesis assay. Results: Elevated AKR1C3 expression was specifically limited to human prostate adenocarcinoma. Microarray and bioinformatics analysis suggested that elevated AKR1C3 expression in PC-3 cells modulates estradiol and androgen metabolism and activates insulin growth factor (IGF)-1 and Akt signaling pathways. Immunoblots confirmed that phosphorylated levels of IGF-1 receptor (IGF-1R) and Akt are significantly up-regulated in PC3-AKR1C3 as compared to mock transfectants. PC3-AKR1C3 transfectants promoted endothelial cell tube formation in Matrigel as compared to parental PC-3 cells and mock transfectants. Conclusion: Microarray and bioinformatics data followed by biological analyses suggest that elevated AKR1C3 expression in PC-3 cells promotes PCa angiogenesis and aggressiveness. These results suggest AKR1C3 can promote the aggressiveness of PCa through modulating estrogen and androgen metabolism with subsequent activation of growth factor IGF-1 and cytoplasmic Akt signaling pathways. Total RNA from mock- and ACR1C3 transfected PC-3 cells was isolated, with 2 or 3 biological replicates each. Gene expression data from AKR1C3 transfected PC-3 cells were compared with mock-transfected data.

Project description:BACKGROUND: Cancer stem-like cells are proposed to sustain solid tumors by virtue of their capacity for self-renewal and differentiation to cells that comprise the bulk of the tumor, and have been identified for a variety of cancers based on characteristic clonal morphologies and patterns of marker gene expression. METHODS: Single cell cloning and spheroid culture studies were used to identify a population of cancer stem-like cells in the androgen-independent human prostate cancer cell line PC3. RESULTS: We demonstrate that, under standard culture conditions, ~10% of PC3 cells form holoclones with cancer stem cell characteristics. These holoclones display high self-renewal capability in spheroid formation assays under low attachment and serum-free culture conditions, retain their holoclone morphology when passaged at high cell density, exhibit moderate drug resistance, and show high tumorigenicity in scid immunodeficient mice. PC3 holoclones readily form spheres, and PC3-derived spheres yield a high percentage of holoclones, further supporting their cancer stem cell-like nature. We identified one gene, FAM65B, whose expression is consistently up regulated in PC3 holoclones compared to paraclones, the major cell morphology in the parental PC3 cell population, and two genes, MFI2 and LEF1, that are consistently down regulated. This molecular profile, FAM65Bhigh/MFI2low/LEF1low, also characterizes spheres generated from parental PC3 cells. The PC3 holoclones did not show significant enriched expression of the putative prostate cancer stem cell markers CD44 and integrin M-NM-12M-NM-21. PC3 tumors seeded with holoclones showed dramatic down regulation of FAM65B and dramatic up regulation of MFI2 and LEF1, and unexpectedly, a marked increase in tumor vascularity compared to parental PC3 tumors, suggesting a role of cancer stem cells in tumor angiogenesis. CONCLUSIONS: These findings support the proposal that PC3 tumors are sustained by a small number of tumor-initiating cells with stem-like characteristics, including strong self-renewal and pro-angiogenic capability and marked by the expression pattern FAM65Bhigh/MFI2low/LEF1low. These markers may serve as targets for therapies designed to eliminate cancer stem cell populations associated with aggressive, androgen-independent prostate tumors such as PC3. (Mol Cancer. 2010 Dec 29;9:319. doi: 10.1186/1476-4598-9-319; PMID: 21190562; PMCID: PMC3024252). Four PC3 cell-derived holoclones, selected based on their clear and unambiguous holoclone morphology and designated holoclones 2H10, 2G7, 1A8 and 5A2, were used for global transcriptome/microarray analysis in direct comparison to parental PC3 cells. Total RNA was prepared from each of four sequential cell passages for each PC3-derived holoclone, and from four passages of parental PC3 cells, 48 h after seeding the cells at 100,000 cells per well of a 6-well plate. For each sample (holoclones or parental PC3 cells), a pool of RNA was prepared by combining equal amounts of RNA from each passage to minimize the effects of passage number and inter-sample variability on gene expression profiles. All RNAs had an RNA integrity number >8.0, determined using an Agilent Bioanalyzer 2100 instrument. cDNAs transcribed from pools of RNA for each holoclone, and for parental PC3 cells, were labeled with Alexa 647 or Alexa 555 dyes in a fluorescent reverse pair (dye swap) design for competitive hybridization to Agilent Whole Human Genome Microarrays.

Dataset Information

CLDN3 in prostate cancer exosomes

Publications

Database-augmented Mass Spectrometry Analysis of Exosomes Identifies Claudin 3 as a Putative Prostate Cancer Biomarker.

Similar Datasets

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