Regulation of the cytoskeleton and cell migration is an important aspect of cancer invasion and metastasis. This project focuses on a novel protein, Nischarin that has an inhibitory role in cell migration and invasion. Integrins have been implicated in cellular processes including the organization of actin cytoskeleton, cell growth and survival, cell motility and cell invasion. We have identified a novel protein that specifically interacts with the a5 cytoplasmic tail;we have termed this protein 'Nischarin'. Recently, with the help of effector domain mutants of Rac1, we demonstrated that Nischarin selectively inhibits Rac-driven signaling cascades that act through p21 activated kinase (PAK). These observations suggest that Nischarin affects the process of cytoskeletal regulation mediated by Rac and PAK. Consistent with this, Nischarin binds to PAK, and inhibits the kinase activity of PAK. Furthermore, our recent data indicate that Nischarin siRNA stimulates lamellipodia formation and cell migration, and activates PAK kinase, suggesting that Nischarin is an important regulator of cell motility. The intent of the proposal is to investigate further the newly described biochemical connection between PAK and Nischarin and its role in tumor cell migration and invasion.
In Aim I we will address the role of Nischarin in the migration and invasion of carcinoma cells by over or underexpressing Nischarin. Also we will examine spatio-temporal localization and regulation of PAK and Nischarin in pseudopodia and invadopodia.
In Aim II, we will study the effect of Nischarin on downstream effectors of PAK including LIMK and cofilin, and will examine how this affects invasion of cancer cells.
In Aim we will evaluate Nischarin's effects on lamellipodia formation by studying lamellipodial dynamics with live cell imaging;we will visualize the effects on lamellipodial protrusion, lamellipodial retraction and membrane ruffles. Evaluation of the role of Nischarin and PAK in the regulation of tumor cell migration and invasion will broaden the current understanding of PAK signaling in carcinoma cells, and may provide new avenues for therapeutic intervention.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA115706-05
Application #
7862414
Study Section
Tumor Progression and Metastasis Study Section (TPM)
Program Officer
Woodhouse, Elizabeth
Project Start
2006-07-25
Project End
2014-05-31
Budget Start
2010-06-01
Budget End
2014-05-31
Support Year
5
Fiscal Year
2010
Total Cost
$195,792
Indirect Cost
Name
Louisiana State Univ Hsc New Orleans
Department
Biochemistry
Type
Schools of Medicine
DUNS #
782627814
City
New Orleans
State
LA
Country
United States
Zip Code
70112
Mimae, Takahiro; Ito, Akihiko; Hagiyama, Man et al. (2014) A novel approach to pseudopodia proteomics: excimer laser etching, two-dimensional difference gel electrophoresis, and confocal imaging. Protoc exch 2014:
Jin, Lianjin; Wessely, Oliver; Marcusson, Eric G et al. (2013) Prooncogenic Factors miR-23b and miR-27b Are Regulated by Her2/Neu, EGF, and TNF-ýý in breast cancer. Cancer Res 73:2884-96
Jain, Prachi; Baranwal, Somesh; Dong, Shengli et al. (2013) Integrin-binding protein nischarin interacts with tumor suppressor liver kinase B1 (LKB1) to regulate cell migration of breast epithelial cells. J Biol Chem 288:15495-509
Kuijl, Coenraad; Pilli, Manohar; Alahari, Suresh K et al. (2013) Rac and Rab GTPases dual effector Nischarin regulates vesicle maturation to facilitate survival of intracellular bacteria. EMBO J 32:713-27
Jain, Prachi; Worthylake, Rebecca A; Alahari, Suresh K (2012) Quantitative analysis of random migration of cells using time-lapse video microscopy. J Vis Exp :e3585
Baranwal, Somesh; Wang, Yanfang; Rathinam, Rajamani et al. (2011) Molecular characterization of the tumor-suppressive function of nischarin in breast cancer. J Natl Cancer Inst 103:1513-28
Wang, Yanfang; Shenouda, Sylvia; Baranwal, Somesh et al. (2011) Integrin subunits alpha5 and alpha6 regulate cell cycle by modulating the chk1 and Rb/E2F pathways to affect breast cancer metastasis. Mol Cancer 10:84
Baranwal, Somesh; Alahari, Suresh K (2011) Rho GTPase effector functions in tumor cell invasion and metastasis. Curr Drug Targets 12:1194-201
Subramani, Dhatchayini; Alahari, Suresh K (2010) Integrin-mediated function of Rab GTPases in cancer progression. Mol Cancer 9:312
Baranwal, Somesh; Alahari, Suresh K (2010) miRNA control of tumor cell invasion and metastasis. Int J Cancer 126:1283-90

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