Breast Cancer is the number one cause of death from malignancy among women in the United States. Cancer can be induced by activation of oncogenes via different mechanisms. Overexpression of the human neu oncogene (also known as HER-2 or c-erbB-2) has been found in approximately 30% of breast tumors and correlates with poor prognosis in breast cancer patients. This clinical correlation suggests that the neu oncogene may play an important role in pathogenesis of breast cancer and can be an excellent target to develop potential anti-cancer drug. The long term goal of this proposal is to understand how the neu oncogene may contribute to development of breast cancer. In this proposal, we will focus on the role of neu oncogene in breast cancer and the molecular mechanisms that cause neu overexpression in the neu-overexpressing breast cancer cells. Therefore, the Specific Aims of this proposal are: 1. Elucidation of the role of neu gene in breast cancer. We will use anti-sense construct of neu gene or adenovirus E1A gene to block neu expression in the neu-overexpressing breast cancer cell lines and then analyze transforming activities of these breast cancer cell lines. The outcome of these experiments may provide us molecular foundation for potential therapeutic application using gene therapy for cancer patients with neu overexpressing tumors. 2. Molecular mechanisms that result in neu overexpression in breast cancer by transcriptional upregulation. We have shown in our preliminary results (Section C.2) that enhanced transcriptional rate is involved in neu overexpression in some breast cancer cell lines such as MDA-MB-453 and BT483. We will continue to study the molecular mechanisms involving transcriptional upregulation by using modern molecular biology techniques and to identify transcriptional factor(s) that upregulates neu expression in breast cancer cells. 3. Molecular mechanisms that result in neu overexpression in breast cancer by post-transcriptional upregulation. As shown in our preliminary results (Section C.3), the half-life of neu mRNA in the neu overexpressing BT474 breast cancer cell line is much longer than that in the control MCF-7 line in which neu gene is not overexpressed. We will try to identify specific RNA element(s) in neu mRNA and cellular factor(s) in the breast cancer cells that may be essential for the prolonged RNA half-life. Identification of factor(s), (from both Specific Aims 2 and 3) that directly controls neu overexpression may provide novel target(s) for development of potential anti-cancer reagents.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
1R01CA058880-01
Application #
3202977
Study Section
Pathology B Study Section (PTHB)
Project Start
1993-02-02
Project End
1996-01-31
Budget Start
1993-02-02
Budget End
1994-01-31
Support Year
1
Fiscal Year
1993
Total Cost
Indirect Cost
Name
University of Texas MD Anderson Cancer Center
Department
Type
Other Domestic Higher Education
DUNS #
001910777
City
Houston
State
TX
Country
United States
Zip Code
77030
Lee, Dung-Fang; Kuo, Hsu-Ping; Chen, Chun-Te et al. (2007) IKK beta suppression of TSC1 links inflammation and tumor angiogenesis via the mTOR pathway. Cell 130:440-55
Yang, Jer-Yen; Xia, Weiya; Hu, Mickey C-T (2006) Ionizing radiation activates expression of FOXO3a, Fas ligand, and Bim, and induces cell apoptosis. Int J Oncol 29:643-8
Kumar, Rakesh; Hung, Mien-Chie (2005) Signaling intricacies take center stage in cancer cells. Cancer Res 65:2511-5
Hu, Mickey C-T; Hung, M C (2005) Role of IkappaB kinase in tumorigenesis. Future Oncol 1:67-78
Li, Yan M; Zhou, Binhua P; Deng, Jiong et al. (2005) A hypoxia-independent hypoxia-inducible factor-1 activation pathway induced by phosphatidylinositol-3 kinase/Akt in HER2 overexpressing cells. Cancer Res 65:3257-63
Ding, Qingqing; Xia, Weiya; Liu, Jaw-Ching et al. (2005) Erk associates with and primes GSK-3beta for its inactivation resulting in upregulation of beta-catenin. Mol Cell 19:159-70
Shao, Ruping; Lee, Dung-Fang; Wen, Yong et al. (2005) E1A sensitizes cancer cells to TRAIL-induced apoptosis through enhancement of caspase activation. Mol Cancer Res 3:219-26
Li, Yan M; Pan, Yong; Wei, Yongkun et al. (2004) Upregulation of CXCR4 is essential for HER2-mediated tumor metastasis. Cancer Cell 6:459-69
Liao, Yong; Zou, Yi-Yu; Xia, Wei-Ya et al. (2004) Enhanced paclitaxel cytotoxicity and prolonged animal survival rate by a nonviral-mediated systemic delivery of E1A gene in orthotopic xenograft human breast cancer. Cancer Gene Ther 11:594-602
Xia, Weiya; Chen, Jin-Shing; Zhou, Xian et al. (2004) Phosphorylation/cytoplasmic localization of p21Cip1/WAF1 is associated with HER2/neu overexpression and provides a novel combination predictor for poor prognosis in breast cancer patients. Clin Cancer Res 10:3815-24

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