Our long term goal is to elucidate the principles by which cAMP controls cell development, proliferation and diffrentiation. cAMP regulates a striking number of physiologic processes, including intermediary metabolism, cellular proliferation, and neuronal signaling by altering basic pattrens of gene expression via activation of cAMP response element (CRE)-directed transcription. The mechanism of the CRE-directed transcription in cell proliferation, however, is largely unexplored. To elucidate the role of the cAMP enhancer (CRE) in the control of cell proliferation, we used transcription factor-decoy oligonucleotide approach. Our studies revealed that a synthetic single-stranded oligonucleotide composed of the CRE sequence, which self-hybridizes to form a duplex/hairpin, can penetrate into cells, compete with CRE enhancers for binding transcription factors and specifically interfere with CRE- and Ap-1-directed transcription in vivo . This oligonucleotide restrained tumor cell proliferation, without affecting the growth of non-cancerous cells. These results suggest that the role of PKA in cancergenesis may involve its transcription of array of genes. Recent development of high throughput DNA microarray enables parallel analysis of expression profiles of thousands of genes in a single hybridization for complex biological systems. Using DNA microarrays, we have conducted a systematic charaterization of gene expression in cells exposed to antisense, either exogenously or endogenously. We have found that in a sequence-specific manner, antisense targeted to protein kinase A RIa alters expression of the clusters of coordinately expressed genes at a specific stage of cell growth, differentiation, and activation. The genes that define the proliferation-transformation signature are down-regulated, whereas those that define the differentiation-reverse transformation signature are up-regulated in antisense-treated cancer cells and tumors, but not in host-livers. In this differentiation signature, the genes showing the highest induction include genes for the G proteins Rap1 and Cdc42. The expression signature induced by the exogenously supplied antisense oligodeoxynucleotide overlaps strikingly with that induced by endogenous antisense gene overexpression. The microarray analysis of gene profiling is also underway in cells treated with CRE-decoy oligonucleotides. This approach will lead us to potentially survey all the genetic pathways and also to discover hitherto unrecognized novel genes that may be involved in tumor growth and tumorigenesis. Furthermore, the discovery of novel genes by this approach coupled with the genetic and biochemical analyses may unravel the mechanism of cAMP-deregulation underlying cancergenesis and offer new targets for drug development and novel treatment strategies for cancer.

Agency
National Institute of Health (NIH)
Institute
Division of Basic Sciences - NCI (NCI)
Type
Intramural Research (Z01)
Project #
1Z01BC008281-20
Application #
6761999
Study Section
(LTIB)
Project Start
Project End
Budget Start
Budget End
Support Year
20
Fiscal Year
2002
Total Cost
Indirect Cost
Name
Basic Sciences
Department
Type
DUNS #
City
State
Country
United States
Zip Code
Nesterova, M; Johnson, N; Cheadle, C et al. (2006) Autoantibody biomarker opens a new gateway for cancer diagnosis. Biochim Biophys Acta 1762:398-403
Cho-Chung, Yoon S (2006) Autoantibody biomarkers in the detection of cancer. Biochim Biophys Acta 1762:587-91
Cho-Chung, Y S (2005) DNA drug design for cancer therapy. Curr Pharm Des 11:2811-23
Nesterova, Maria V; Cho-Chung, Yoon S (2004) Antisense protein kinase A RIalpha inhibits 7,12-dimethylbenz(a)anthracene-induction of mammary cancer: blockade at the initial phase of carcinogenesis. Clin Cancer Res 10:4568-77
Cho-Chung, Yoon S (2004) Antisense protein kinase A RI alpha-induced tumor reversion: portrait of a microarray. Biochim Biophys Acta 1697:71-9
Cho-Chung, Yoon S (2003) cAMP signaling in cancer genesis and treatment. Cancer Treat Res 115:123-43
Cho, Yee Sook; Cho-Chung, Yoon S (2003) Antisense protein kinase A RIalpha acts synergistically with hydroxycamptothecin to inhibit growth and induce apoptosis in human cancer cells: molecular basis for combinatorial therapy. Clin Cancer Res 9:1171-8
Kim, Young Hoon; Lim, Do Sun; Lee, Ji Hye et al. (2003) Gene expression profiling of oxidative stress on atrial fibrillation in humans. Exp Mol Med 35:336-49
Cheadle, Chris; Cho-Chung, Yoon S; Becker, Kevin G et al. (2003) Application of z-score transformation to Affymetrix data. Appl Bioinformatics 2:209-17
Cho-Chung, Yoon S (2003) CRE-enhancer DNA decoy: a tumor target-based genetic tool. Ann N Y Acad Sci 1002:124-33

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