IQUIBICEN   23947
INSTITUTO DE QUIMICA BIOLOGICA DE LA FACULTAD DE CIENCIAS EXACTAS Y NATURALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
HEME-OXYGENASE 1 (HO-1) RE-ORCHESTRATES PROSTATE CANCER CELLULAR ARCHITECTURE TOWARDS A MORE EPITHELIAL-LIKE MORPHOLOGY
Autor/es:
ESTEFANIA LABANCA; GERALDINE GUERON; ALEJANDRA PAEZ; CARLA PALLAVACINI; JIMENA GIUDICE; NICOLAS ANSELMINO; EMILIANO ORTIZ; FEDERICO SCHUSTER; LUCIANA BRUNO; VALERIA LEVI; ELBA VAZQUEZ; NORA NAVONE
Lugar:
Galveston
Reunión:
Conferencia; Gordon Research Seminar: Directed Cell Migration; 2015; 2015
Institución organizadora:
Gordon Research Conferences
Resumen:
Cellular motility is a coordinated process that involves variations in the dynamics of the actin cytoskeleton and its interplay with focal adhesions. It is the re-arrangement of actin and its attachment to focal adhesions at the leading edge of a migrating cell, which generates the driving force necessary for movement. The loss of cell-cell adhesion enables cancer cells to dissociate from the primary tumor mass and changes in cell-matrix interaction allows the cells to invade the surrounding stroma. Heme oxygenase-1 (HO-1), the rate-limiting enzyme in heme degradation, plays a pivotal role in prostate cancer (PCa), hindering cell proliferation, migration and invasion. HO-1 is also capable of modulating the adhesive properties and morphology of PCa cells. We have began to screen HO-1 molecular partners through a proteomics and bioinformatics approach, to determine the molecular mechanisms by which HO-1 regulates cell morphology, and at the same time quantify and compare microtubule and actin dynamics at the leading edge level in PCa cells. FLAG immunoprecipitation assays were performed using lysates from PC3 cells transfected with FLAG-tagged HO-1, and the isolated proteins were subjected to LC/ESI-MSMS analysis. Protein interaction network and gene ontology analyses of HO-1 interacting proteins (performed with Metacore, GeneMANIA and DAVID) showed enrichment of proteins associated with the cytoskeleton organization, transportation and membrane bounding. Of note, gelsolin, lasp1, SIPA1L1, testin, moesin, tropomodulin and vinculin, all HO-1 interacting proteins were associated to the dynamics of the actin stress fibers. Effector genes were analyzed by RT-qPCR Oligo GEArray human cell motility microarray analysis revealing HO-1 modulation of genes such as Actin alpha 3 and MMP14, intimately related to cell locomotion and motility. To quantify contacts among cells, PC3 cells were exposed to hemin (80μM, 24h), a pharmacological inducer of HO-1, fixed and stained with phalloidin-rhodamin. We selected regions in which the filopodia from two neighboring cells touched each other, considered as ?contacts?, and divided these regions into segments where the distance between the cells remained constant. An intensity profile for each of these sectors was analyzed with a custom made algorithm to count contacts. A 'contact density' was defined for each region as the ratio between the number of contacts and the length of the profile. Microtubule dynamics in PC3 cells was evaluated using confocal and stochastic optical reconstruction microscopy (STORM). Although no variation of the persistence length of microtubules was found when cells over-expressed HO-1, a significant higher proportion of filopodia-like protrusions among neighboring cells and increased cellular contact were observed under HO-1 modulation. These results show that HO-1 modulation in PCa induces the remodeling of the actin filament architecture at filopodia, altering cellular morphology, towards a less aggressive phenotype.