Study the Anti-Tumor Activity of E1A Gene Therapy---Focus on the Function and Biogenesis of microRNA

Breast cancer is the major cause of death for women and well known that breast cancer is one of the most common cancers for women. Therefore, there is an urgent need to develop novel agents for breast cancer diagnosis, prognosis, prevention and therapy. The adenoviral type 5 E1A (E1A) associates with multiple anti-cancer activities and has been tested in multiple clinical trials in a gene therapy setting for breast, ovarian and head and neck cancer patients. Recent evidences reveal that various miRNAs modulate the signal molecules involve in apoptosis, proliferation, angiogenesis, or metastasis and may in turn contribute to the cancer progression. The goal of this application is to understand the miRNA regulation and epigenetic molecular mechanisms of E1A-mediated anti-cancer activities. To reach this goal, we will focus on how E1A may regulate miRNA processing and expression through the novel signaling pathways and exert suppressive effects on tumor progression in breast cancer. Three SPECIFIC AIMS are proposed. SPECIFIC AIM 1: Study the biological significance of candidate miRNAs in E1A-mediated anti-cancer activity. 1-a: Identify the differential expression of miRNAs between breast cancer cells expression of control vector or E1A-expressing vector. 1-b: Further confirm the differential expression of miRNA from microarray analysis, we using real time RT-PCR to validate the expression of candidate miRNAs. 1-c: Define whether the candidate miRNAs involves in E1A-mediated anti-cancer activity. SPECIFIC AIM 2: Define the molecular mechanisms and potential targets of E1A-regulated candidate miRNAs. 2-a: Study the epigenetic regulations and molecular mechanism involving in the regulation of miRNA by E1A. 2-b: To study the role of secreted miRNAs in E1A-mediated cellular function. 2-c: To further confirm the linkage between E1A, signaling molecules, candidate miRNAs and subsequent biological functions. 2-d: Identify the down-stream targets of E1A-regulated candidate miRNAs. SPECIFIC AIM 3: Investigate the physiological significance of E1A-mediated signaling molecules and candidate miRNAs. According to the findings from AIM1 and AIM2, E1A inhibits cancer progression through miRNAs regulations need to be further investigated in animal model and cancer specimens. Success of these SPECIFIC AIMS will help us to understand better the molecular mechanisms of E1A-mediated anti-cancer activities. These will include how E1A-mediated miRNAs biogenesis may reduce the ability of breast cancer cell to metastasis, and how E1A may inhibit tumor progression.