WFYellow(F08) Research Proposal

Allen and Jess's 20.109 Module 3 Research Proposal Resource Page

Idea(s):

1. 1. Identify proteins associated with extracellularlly-presented Hsp90 (in particular HER-2/ErbB2), which is known to be over-expressed in proliferating cancer cells.
   2. Identify the membrane targeting sequence of Hsp90, produce interfering RNA, and observe phenotypic changes.
   3. High membrane-bound Hsp90 expression also correlates with the rounded morphology of proliferative cancer. One potential research idea is to study the induction of flat vs. rounded morphology pathways and observe whether or not return of flattened morphology reduces cell proliferation, metastasis, and tissue invasion.

Links to papers

1. Cid C, Regidor I, Poveda PD, and Alcazar A. Expression of heat shock protein 90 at the cell surface in human neuroblastoma cells. Cell Stress Chaperones. 2009 May;14(3):321-7. DOI:10.1007/s12192-008-0076-7 |
2. Sidera K, Gaitanou M, Stellas D, Matsas R, and Patsavoudi E. A critical role for HSP90 in cancer cell invasion involves interaction with the extracellular domain of HER-2. J Biol Chem. 2008 Jan 25;283(4):2031-41. DOI:10.1074/jbc.M701803200 |
3. Eustace BK, Sakurai T, Stewart JK, Yimlamai D, Unger C, Zehetmeier C, Lain B, Torella C, Henning SW, Beste G, Scroggins BT, Neckers L, Ilag LL, and Jay DG. Functional proteomic screens reveal an essential extracellular role for hsp90 alpha in cancer cell invasiveness. Nat Cell Biol. 2004 Jun;6(6):507-14. DOI:10.1038/ncb1131 |
4. Sidera K and Patsavoudi E. Extracellular HSP90: conquering the cell surface. Cell Cycle. 2008 Jun 1;7(11):1564-8. DOI:10.4161/cc.7.11.6054 |

5. has been found to interact with many client proteins inside cancerous cells. These include mutant versions of HER-2 receptor, c-Raf-1, Akt/PKB, CDK4 and p53. The inhibitor geldanamycin has been found to strongly bind to Hsp90 and decrease its activity, which in turn decreases the activity of these client proteins. Hsp90 has recently been found outside the cell, bound to the membrane. The authors suggest that Hsp90 interacts with the extracellular segment of HER-2, which in turn actives a protein called Erb-3, which, through a signaling pathway, leads to greater cell mobility. The authors propose that inhibiting extracellular Hsp90 can limit metastasis.

6. Eustace BK and Jay DG. Extracellular roles for the molecular chaperone, hsp90. Cell Cycle. 2004 Sep;3(9):1098-100.
7. Tsutsumi S and Neckers L. Extracellular heat shock protein 90: a role for a molecular chaperone in cell motility and cancer metastasis. Cancer Sci. 2007 Oct;98(10):1536-9. DOI:10.1111/j.1349-7006.2007.00561.x |

These papers more or less say similar things. Hsp90 has been found to be associated with the extracellular membrane, and is most likely related to allowing cancerous cells to metastasize.

Methods
cell fractionation
TAP (or other)-tagging
immunofluorescence