BIOINFORMATICS ANALYSIS OF HEME-OXYGENASE 1 (HO-1) INTERACTOME IN PROSTATE CANCER

ORTIZ, EMILIANO GERMÁN; PAEZ, ALEJANDRA VERÓNICA; GIUDICE, JIMENA; VALACCO, PIA; LEONARDI, DAIANA BEATRIZ; COTIGNOLA, JAVIER HERNÁN; MARTÍ, MARCELO; VAZQUEZ, ELBA SUSANA; GUERON, GERALDINE

Bariloche

Simposio; Third South American Symposium in Signal and Molecular Medicine SISTAM 2015; 2015

SISTAM

Prostate Cancer (PCa) is the second leading cause of cancer death in Americanmen. The integration of proteomics with appropriate bioinformatics tools, providepromising findings that may effectively translate into clinical applications.Bioinformatics changes the perspective of proteomics, creating a proper scaffoldfor data storage, analyses and integration. The aim of this work was to use aproteomic and bioinformatics based approach to identify HO-1 molecularpartners. Recombinant GST-HO-1 protein complexes were pulled-down andprotein complexes were subject to in-solution or in-gel digestion and then LCMS/MS.The C-18 reverse phase LC-MS/MS rendered a set of 46 HO-1 candidatepartners, which were differentially expressed in PC3 cells transfected with GSTHO-1respect to control cells (transfection with empty vector GST), thus definingour preliminary HO-1 interactome. For this set of proteins we performed a proteininteraction network analysis and an ontology analysis. Results revealed anenrichment of proteins associated to several sub-categories of the cellularcomponent, molecular function and biological processes classifications. This listwas further clustered into five functional categories: DNA and transcription, RNAprocessing, actin and transport-related proteins and other proteins. Our workinghypothesis emerges from the detection of nuclear molecular partners of HO-1.This set of nuclear acting proteins comprises the HO-1 interactome that mountsinto a transcriptional/ RNA processing regulatory machinery, responsible formodulating the HO-1 target genes. We focused our studies on the RNA processingcategories. Interestingly, HO-1 interacts with TRIM28, a modulator of signalingpathways during carcinogenesis, that has been reported to ubiquitinate anddestabilize p53 in association with members of the MAGE (melanoma antigen)family of cancer testis antigens. MAGE protein family associates to poor prognosisin cancer. Our results show that MAGE A11 is present in PCa cells and that HO-1pharmacological induction (hemin 24 h, 80 µM) decreases MAGE A11 proteinexpression, favoring a less aggressive phenotype. Altogether, this is the firstapproach in building the HO-1 interactome in prostate cancer, which potentiallycould define a subset of candidate biomarkers for therapeutic intervention.