Approximately 15-20% of breast cancers have a triple negative phenotype (negative for ER and PR expression and lack ErbB2 overexpression) that correlates with aggressive cancer and limited treatment options. We have developed an in vivo screen for defining the role of specific kinases in tumorigenesis and metastasis of breast cancer cells. Triple negative and triple positive breast cancer lines were used for shRNA-mediated knock down of specific kinases. The genetically altered lines (expressing luciferase in addition to specific shRNA gene knockdown) are injected into the mammary fat pad of female SCID mice. Tumor growth and vascularization is monitored longitudinally over an 8 week period using a micro-probe ultrasound system. Metastasis is monitored by bioluminescence imaging. The assay provides an in vivo screen for analysis of proteins that control the growth, vascularization and metastasis of breast tumors. MAP3Ks are the first tier of kinases regulating the MAP kinase signaling pathways that lead to the activation of the MAPKs ERKl/2, p38, JNK and ERKS. MAPSKs control expression of genes important for regulating the cell cycle, cytokine and protease expression and apoptosis. In a screen of 9 MAP3Ks, MEKK2 was identified as a key regulator of metastasis using MDA-MB-231 (triple negative basal) and BT474 (triple positive luminal) breast adenocarcinoma cells in the in vivo tumorigenesis assay. MEKK2 is a MAP3K that regulates the activation of the JNK and ERK5 pathways via activation of MKK7 and MEKS. We have shown that MEKK2 expression is required for EGFR (ErbBI) and ErbB2/Neu activation of ERKS in MDA-MB-231 and BT474 cells, respectively. Our hypothesis is that the MAP3K MEKK2 functions as a critical signaling node within the cell signaling network stimulating tumor growth and metastasis in response to ErbB and possibly other tyrosine kinases. The goal of this proposal is to genetically define the role of MEKK2 in triple negative breast cancer tumor growth and metastasis and to develop a MEKK2 small molecule inhibitor.
Specific aim 1 involves defining the role of MEKK2-MEK5-ERK5 signaling in tumorigenesis and metastasis of triple negative breast cancer cells using the in vivo xenograft assay.
In specific aim 2, we propose to elucidate the mechanism by which MEKK2 gets activated by ErbB1/2 using MEKK2 mutants in biochemical and cell-based activation assays.
In specific aim 3, a small molecule biochemical screen will be developed to identify compounds that specifically inhibit MEKK2 kinase activity. MEKK2 inhibitors will be tested for MAPK pathway specificity in cell-based assays and profiled for specificity against the kinome. In future studies, these MEKK2 inhibitors will be tested for anti-tumor efficacy in genetically engineered mouse models (GEMMs) of breast cancer.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Specialized Center--Cooperative Agreements (U54)
Project #
5U54CA156735-03
Application #
8381984
Study Section
Special Emphasis Panel (ZCA1-SRLB-3)
Project Start
Project End
Budget Start
2012-09-01
Budget End
2013-08-31
Support Year
3
Fiscal Year
2012
Total Cost
$122,856
Indirect Cost
Name
North Carolina Central University
Department
Type
DUNS #
783691801
City
Durham
State
NC
Country
United States
Zip Code
27707
Liu, Yongjing; Xiong, Zhaohui; Beasley, Andrea et al. (2016) Personalized and targeted therapy of esophageal squamous cell carcinoma: an update. Ann N Y Acad Sci 1381:66-73
Zhao, Qingxia; Zhao, Ming; Parris, Amanda B et al. (2016) Genistein targets the cancerous inhibitor of PP2A to induce growth inhibition and apoptosis in breast cancer cells. Int J Oncol 49:1203-10
Li, Jing; Chen, Xiaoxin Luke; Shaker, Anisa et al. (2016) Contribution of immunomodulators to gastroesophageal reflux disease and its complications: stromal cells, interleukin 4, and adiponectin. Ann N Y Acad Sci 1380:183-194
Ahmad, Syed; Johnson, Gary L; Scott, John E (2015) Identification of ponatinib and other known kinase inhibitors with potent MEKK2 inhibitory activity. Biochem Biophys Res Commun 463:888-93
Chen, Hao; Beasley, Andrea; Hu, Yuhui et al. (2015) A Zebrafish Model for Studies on Esophageal Epithelial Biology. PLoS One 10:e0143878
Reaves, Denise K; Ginsburg, Erika; Bang, John J et al. (2015) Persistent organic pollutants and obesity: are they potential mechanisms for breast cancer promotion? Endocr Relat Cancer 22:R69-86
D'Arcy, Monica; Fleming, Jodie; Robinson, Whitney R et al. (2015) Race-associated biological differences among Luminal A breast tumors. Breast Cancer Res Treat 152:437-48
Li, Puyu; Zhao, Ming; Parris, Amanda B et al. (2015) p53 is required for metformin-induced growth inhibition, senescence and apoptosis in breast cancer cells. Biochem Biophys Res Commun 464:1267-74
Hood, Sula; Linnan, Laura; Jolly, David et al. (2015) Using the PRECEDE Planning Approach to Develop a Physical Activity Intervention for African American Men Who Visit Barbershops: Results From the FITShop Study. Am J Mens Health 9:262-73
House, Alan J; Daye, Laura R; Tarpley, Michael et al. (2015) Design and characterization of a photo-activatable hedgehog probe that mimics the natural lipidated form. Arch Biochem Biophys 567:66-74

Showing the most recent 10 out of 41 publications