Myc is an important oncogene widely studied in model systems and implicated in many human cancers. We have uncovered evidence for a robust genetic instability phenotype, involving DNA palindrome formation and gene copy number change, associated with constitutive Myc oncogene over expression, and resultant lymphomagenesis, in the chicken bursa of Fabricius. We propose to characterize this phenomenon more completely. To accomplish this general goal we have developed several tools for genomic analysis including a chicken cDNA microarray effective for array-based comparative genome hybridization (Array CGH) and genome-wide analysis of palindrome formation (GAPF) for analysis of lymphoma derived cell lines, and of tissues representing early and late stages of neoplastic bursal development in vivo. Specific planned experiments employ DT40, a myc-over expressing bursal lymphoma-derived cell line that demonstrates extensive DNA copy number change and palindrome formation that differs in different clonal isolates. We will:(a) determine the time scale over which these changes occur,(b) attempt to test effects of lower c-myc expression levels on stability, and (c) test the effects of deletion of several DNA repair genes including those demonstrated to be important for recombination in DT40: Myc is known to bind DNA at many loci, both in transcriptional regulatory regions and other regions of unknown function. We will map sites of Myc binding in the DT40 genome and determine if there is a relationship between Myc binding sites and sites of palindrome formation. We have observed that many sites of palindrome formation in bursal lymphomas and DT40 are expressed as RNA. We will adapt our array-based technology to determine whether RNA expressed from DNA palindromes formed during tumorigenesis has double-stranded character. Such dsRNAs are potential substrates for the formation of functional small interfering RNA which could play a role in gene silencing during tumor development. Finally, we will determine if Myc-ihduced instability occurs in mammalian systems. Palindrome formation will be assessed in Emu-c-myc transgenic mice which develop lympomas. In human P493-6 B-cells, in which Myc can be experimentally regulated, we will determine if induction of Myc results in palindrome formation at sites of Myc binding. In this fashion we hope to establish whether Myc-induced genomic instability merits wider exploration in human neoplasm. ? ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
2R01CA020068-30A1
Application #
7303940
Study Section
Cancer Genetics Study Section (CG)
Program Officer
Mietz, Judy
Project Start
1976-03-01
Project End
2009-08-31
Budget Start
2007-09-11
Budget End
2008-08-31
Support Year
30
Fiscal Year
2007
Total Cost
$264,000
Indirect Cost
Name
Fred Hutchinson Cancer Research Center
Department
Type
DUNS #
078200995
City
Seattle
State
WA
Country
United States
Zip Code
98109
Neiman, Paul E; Elsaesser, Katrina; Loring, Gilbert et al. (2008) Myc oncogene-induced genomic instability: DNA palindromes in bursal lymphomagenesis. PLoS Genet 4:e1000132
Kimmel, Robert R; Agnani, Shivali; Yang, Yin et al. (2008) DNA copy-number instability in low-dose gamma-irradiated TK6 lymphoblastoid clones. Radiat Res 169:259-69
Kimmel, Robert R; Zhao, Lue Ping; Nguyen, Doan et al. (2006) Microarray comparative genomic hybridization reveals genome-wide patterns of DNA gains and losses in post-Chernobyl thyroid cancer. Radiat Res 166:519-31
Neiman, P E; Kimmel, R; Icreverzi, A et al. (2006) Genomic instability during Myc-induced lymphomagenesis in the bursa of Fabricius. Oncogene 25:6325-35
Neiman, Paul E; Burnside, Joan; Elsaesser, Katrina et al. (2006) Analysis of gene expression, copy number and palindrome formation with a Dt40 enriched cDNA microarray. Subcell Biochem 40:245-56
Burnside, Joan; Neiman, Paul; Tang, Jianshan et al. (2005) Development of a cDNA array for chicken gene expression analysis. BMC Genomics 6:13
Brown, Cheryl Y; Bowers, Sandra J; Loring, Gibert et al. (2004) Role of Mtd/Bok in normal and neoplastic B-cell development in the bursa of Fabricius. Dev Comp Immunol 28:619-34
Parghi, Sean S; Brandvold, Kimberly A; Bowers, Sandra J et al. (2004) Reduced Myc overexpression and normal B-cell differentiation mediate resistance to avian leukosis virus lymphomagenesis. Oncogene 23:4413-21
Black, Elizabeth J; Clair, Timothy; Delrow, Jeffrey et al. (2004) Microarray analysis identifies Autotaxin, a tumour cell motility and angiogenic factor with lysophospholipase D activity, as a specific target of cell transformation by v-Jun. Oncogene 23:2357-66
Cheng, Chun; Kimmel, Robert; Neiman, Paul et al. (2003) Array rank order regression analysis for the detection of gene copy-number changes in human cancer. Genomics 82:122-9

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