| Abstract: |
Secreted proteins play a key role in cell signaling, communication, and migration. We recently described the development of an aggressive variant (T24M) of the bladder cancer cell line T24. Using this cell line model, the objective of our work was the identification of secreted proteins involved in the acquisition of the aggressive phenotype. Using in vitro assays, we demonstrate that conditioned media of the T24M cells promote motility of the parental less aggressive T24 cells. Proteomic analysis of cell culture conditioned media by the use of 2-dimensional gel electrophoresis coupled to MALDI TOF MS and LC-MS approaches resulted in enrichment and detection of multiple classical extracellular and secreted proteins such as fibronectin, cystatin, fibrillin, fibulin, interleukin 6, etc. Comparison of the secretome of the T24 and T24M cells indicated differences in proteins with potential involvement in the mechanisms of cell aggressiveness including SPARC, tPA, and clusterin. These findings were further confirmed by Western blot analysis. In the case of SPARC, further studies involving transwell assays indicated that blockage of the protein in the presence of SPARC-specific Abs results in decreased cell motility. Collectively, our study provides a 2DE-based comprehensive analysis of bladder cancer cell secretome. The results indicate various secreted proteins with potential involvement in bladder cancer cell aggressiveness and more specifically provide initial evidence for special role of SPARC in bladder cancer cell motility and invasiveness. © 2010 American Chemical Society. |
| Keywords: |
immunohistochemistry; controlled study; human cell; mass spectrometry; protein analysis; proteome; phenotype; neoplasm proteins; tumor markers, biological; culture medium; cell line; cancer cell culture; in vitro study; cell line, tumor; proteomics; bladder cancer; urinary bladder neoplasms; cancer cell; western blotting; interleukin 6; protein secretion; cell movement; neoplasm invasiveness; matrix assisted laser desorption ionization time of flight mass spectrometry; electrophoresis, gel, two-dimensional; liquid chromatography; cell communication; cell invasion; cell motility; secretome; cystatin; clusterin; two dimensional gel electrophoresis; fibronectin; spectrometry, mass, matrix-assisted laser desorption-ionization; 2de; sparc; t24; fibrillin; fibulin; osteonectin; aggressiveness
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