The directed cell migration of tumor cells in response to a chemotactic stimulus is mediated by mechanisms that induce formation of free F-actin barbed-ends, extensions of existing filaments and actin branching at the leading edge, which results in membrane protrusion towards the stimulus. Key mediators of these processes are ADF/cofilin, which induces actin severing and barbed end formation, the actin nucleation factors of the WASp family and the Arp2/3 complex, which induce actin nucleation and dendritic branching, as well as Ena/VASP, which competes with the capping protein (CP). We made the striking observation that the serine/threonine kinase Protein Kinase D1 (PKD1) completely inhibits actin incorporation at barbed ends at the leading edge and that this results in the inhibition of actin-mediated directed cell migration. This proposal is designed to understand the impact of PKD1 on the key processes regulating actin turnover at the leading edge of migrating tumor cells. It is our hypothesis that PKD1 inhibits actin remodeling processes at multiple levels. Specifically we hypothesize that PKD1 mediates its effects through regulation of ADF/cofilin, the Arp2/3 complex and Ena/VASP. We propose that PKD1 impacts all these key-events to mediate its profound inhibitory effects observed on barbed end formation, actin incorporation and cell migration of tumor cells.
Three Specific Aims will be investigated in this proposal: We will determine how PKD1 regulates ADF/cofilin activity (Specific Aim 1);identify how PKD1 regulates Arp2/3 functions (Specific Aim 2);and analyze how PKD1-mediated phosphorylation of VASP contributes to directed cell motility (Specific Aim 3). Successful completion of this proposal will identify novel functions for PKD1 in actin remodeling processes at the leading edge of motile tumor cells. This knowledge will be important for the development of novel strategies to inhibit tumor cell migration and invasion.

Public Health Relevance

Migration of tumor cells has an important function in tumor expansion and metastasis. This proposal will investigate the molecular mechanisms of how the serine/threonine kinase PKD1 regulates actin dynamics at the leading edge of tumor cells and inhibits tumor cell migration.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM086435-02
Application #
8072986
Study Section
Nuclear and Cytoplasmic Structure/Function and Dynamics Study Section (NCSD)
Program Officer
Deatherage, James F
Project Start
2010-06-01
Project End
2014-04-30
Budget Start
2011-05-01
Budget End
2012-04-30
Support Year
2
Fiscal Year
2011
Total Cost
$265,073
Indirect Cost
Name
Mayo Clinic Jacksonville
Department
Type
DUNS #
153223151
City
Jacksonville
State
FL
Country
United States
Zip Code
32224
Durand, Nisha; Borges, Sahra; Storz, Peter (2016) Protein Kinase D Enzymes as Regulators of EMT and Cancer Cell Invasion. J Clin Med 5:
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Borges, Sahra; Perez, Edith A; Thompson, E Aubrey et al. (2015) Effective Targeting of Estrogen Receptor-Negative Breast Cancers with the Protein Kinase D Inhibitor CRT0066101. Mol Cancer Ther 14:1306-16
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Durand, Nisha; Borges, Sahra; Storz, Peter (2015) Functional and therapeutic significance of protein kinase D enzymes in invasive breast cancer. Cell Mol Life Sci 72:4369-82
Liou, Geou-Yarh; Döppler, Heike; Braun, Ursula B et al. (2015) Protein kinase D1 drives pancreatic acinar cell reprogramming and progression to intraepithelial neoplasia. Nat Commun 6:6200
Döppler, Heike; Bastea, Ligia; Borges, Sahra et al. (2015) The phosphorylation status of VASP at serine 322 can be predictive for aggressiveness of invasive ductal carcinoma. Oncotarget 6:29740-52
Zheng, Hanqiu; Shen, Minhong; Zha, Yin-Lian et al. (2014) PKD1 phosphorylation-dependent degradation of SNAIL by SCF-FBXO11 regulates epithelial-mesenchymal transition and metastasis. Cancer Cell 26:358-373
Döppler, Heike; Bastea, Ligia I; Borges, Sahra et al. (2014) Protein kinase d isoforms differentially modulate cofilin-driven directed cell migration. PLoS One 9:e98090
Borges, Sahra; Döppler, Heike R; Storz, Peter (2014) A combination treatment with DNA methyltransferase inhibitors and suramin decreases invasiveness of breast cancer cells. Breast Cancer Res Treat 144:79-91

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