) The po transcript of the human c-myc gene is initiated over 600 bp upstream of the major Pl/P2 start sites, and its sequence corresponds to regulatory regions of the core promoter DNA. We hypothesize that this 5'-untranslated RNA sequence is a fundamental participant in the transcriptional regulation of c-myc and the ultimate determination of cellular phenotype. In preliminary experiments, we have determined that the PO RNA is capable of binding specific DNA sequences within the core Pl promoter and the first exon of c-myc. Furthermore, we have found that enforced expression of the sequence unique to the po transcript is associated with drastic, alterations in phenotype of malignant cells, including greater than 90 percents decrease in anchorage- independent growth in soft agar, and complete loss of the ability to form tumors in I immunodeficient mice. We propose to explore the potential therapeutic utility of this RNA sequence for modulating c-myc expression and interfering with proliferation, invasion, and metastasis of human breast cancer cells.
The Specific Aims are: 1. Investigate the potential of the 5'-untranslated RNA sequence of the human c-myc PO transcript to regulate c-myc expression, by interacting with and blocking access to particular segments of the promoter / template DNA, or by specifically recruiting /sequestering individual polypeptide transcription factors. 2. Enforcibly express the 5'-untranslated sequence of the c-myc PO transcript in malignant and nontransformed human breast cells, to evaluate the potential therapeutic utility of this natural RNA sequence for modulating the proliferative and invasive capacity of the malignant cells. 3. Assess the degree to which artificial manipulation of the PO 5'-untranslated sequence alters the inherent tumorigenic, invasive, and metastatic potential of human breast carcinoma xenografts in immunocompromised mice.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21CA087312-02
Application #
6514644
Study Section
Special Emphasis Panel (ZCA1-SRRB-D (M1))
Program Officer
Freeman, Colette S
Project Start
2001-05-01
Project End
2004-04-30
Budget Start
2002-05-01
Budget End
2004-04-30
Support Year
2
Fiscal Year
2002
Total Cost
$107,625
Indirect Cost
Name
University of Alabama Birmingham
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
004514360
City
Birmingham
State
AL
Country
United States
Zip Code
35294
Blume, Scott W; Miller, Donald M; Guarcello, Vincenzo et al. (2003) Inhibition of tumorigenicity by the 5'-untranslated RNA of the human c-myc P0 transcript. Exp Cell Res 288:131-42