Aurora-A kinase is overexpressed in many human cancers and leads to centrosome amplification resulting in multipolar spindles, chromosome segregation defects and aneuploidy. Aurora-A belongs to a family of serine/threonine mitotic kinases involved in centrosome separation, duplication and maturation as well as in bipolar spindle assembly. In this work, we demonstrate that Aurora-A is both amplified and overexpressed in human pancreatic cancer cell lines, with a 2-5 fold increase in gene copy number and a 3-4 fold increase in protein levels compared to controls. Aurora-A is also amplified and overexpressed in pancreatic cancers taken directly from patients. An immunohistochemistry of tissues taken directly from patients demonstrated an overexpression of Aurora-A in 26 of 28 pancreatic cancers compared to 0 of 18 normal pancreas samples. Antisense nucleotides specifically targeted at Aurora-A arrest the cell cycle in pancreatic cancer cells, indicating the potential of Aurora-A as a therapeutic target in pancreatic cancer. To understand the role of Aurora-A at the centrosome, we investigated the mechanism of how Aurora-A is targeted to the centrosome. We used deletion fragment analysis of Aurora-A to identify a specific region that is required to localize to the centrosome. We also show that subcellular localization of Aurora-A is independent of its intrinisic kinase activity and its phosphorylation states. These results show that Aurora-A is targeted to the centrosome by a mechanism that does not require its kinase activity and phosphorylation of T288 and T287. Furthermore, the region containing the catalytic domain, 131-333, is sufficient to localize Aurora-A to the centrosome.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/194492 |
| Date | January 2005 |
| Creators | Rojanala, Sangeeta |
| Contributors | Bosco, Giovanni, Bosco, Giovanni, Schroeder, Joyce, Nagle, Ray, Parker, Roy |
| Publisher | The University of Arizona. |
| Source Sets | University of Arizona |
| Language | English |
| Detected Language | English |
| Type | text, Electronic Dissertation |
| Rights | Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. |
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