Ionizing radiation is a well-known human carcinogen linked to a variety of cancers including thyroid cancer, leukemia, breast cancer and soft tissue sarcomas. The molecular mechanisms of radiation-induced carcinogenesis remain poorly understood. Significant evidence has been accumulated supporting the dominant role of chromosomal rearrangements in the carcinogenesis initiated by radiation exposure. Since ionizing radiation induces double strand DNA breaks, it is conceivable that chromosomal rearrangements are formed directly by mis-rejoining of free DNA ends produced by radiation and located close to each other in the nucleus. In thyroid cancer, RET/PTC rearrangements, which usually form via an inversion in chromosome 10q, are a molecular signature of radiation-associated tumors. Recently, we have established an in vitro model of dose-dependent generation of RET/PTC in human thyroid cells after exposure to radiation. This system will serve as an important tool for further studies of radiation-induced DNA damage and chromosomal rearrangements. In this proposal, we will test the hypotheses that RET/PTC rearrangement is a direct result of mis-rejoining of double-strand DNA breaks induced by radiation exposure. Specifically, we will characterize the frequency and spectrum of radiogenic breaks and rejoining kinetics in the RET gene region, test if one or two DNA breaks are required for the rearrangement, and compare the effects of irradiation and 1-131 on the generation of RET/PTC rearrangements. We will also determine the fate of cells after they acquire the rearrangement and will characterize the earliest stages of radiation-induced carcinogenesis initiated by various RET/PTC types. Finally, we will find whether these rearrangements are predisposed by altered function of several genes playing a central role in double-strand break repair in vitro. Then, we will test the role of alterations in these genes in predisposition to radiation-induced thyroid cancer in human populations. These studies will expand our understanding of the mechanisms of radiation-induced carcinogenesis and provide important information for radiation risk assessment and protection applicable to a variety of areas such as clinical use of external radiotherapy and I-131, occupational radiation exposure, space exploration, and radioprotection from potential accidents involving nuclear power reactors or radiological terrorism.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA088041-09
Application #
7775122
Study Section
Integrative and Clinical Endocrinology and Reproduction Study Section (ICER)
Program Officer
Pelroy, Richard
Project Start
2001-07-01
Project End
2012-02-28
Budget Start
2010-03-01
Budget End
2011-02-28
Support Year
9
Fiscal Year
2010
Total Cost
$231,452
Indirect Cost
Name
University of Pittsburgh
Department
Pathology
Type
Schools of Medicine
DUNS #
004514360
City
Pittsburgh
State
PA
Country
United States
Zip Code
15213
Evdokimova, Viktoria N; Gandhi, Manoj; Nikitski, Alyaksandr V et al. (2018) Nuclear myosin/actin-motored contact between homologous chromosomes is initiated by ATM kinase and homology-directed repair proteins at double-strand DNA breaks to suppress chromosome rearrangements. Oncotarget 9:13612-13622
Efanov, Alexey A; Brenner, Alina V; Bogdanova, Tetiana I et al. (2018) Investigation of the Relationship Between Radiation Dose and Gene Mutations and Fusions in Post-Chernobyl Thyroid Cancer. J Natl Cancer Inst 110:371-378
Panebianco, Federica; Kelly, Lindsey M; Liu, Pengyuan et al. (2017) THADA fusion is a mechanism of IGF2BP3 activation and IGF1R signaling in thyroid cancer. Proc Natl Acad Sci U S A 114:2307-2312
Seethala, Raja R; Chiosea, Simion I; Liu, Cheng Z et al. (2017) Clinical and Morphologic Features of ETV6-NTRK3 Translocated Papillary Thyroid Carcinoma in an Adult Population Without Radiation Exposure. Am J Surg Pathol 41:446-457
Picarsic, Jennifer L; Buryk, Melissa A; Ozolek, John et al. (2016) Molecular Characterization of Sporadic Pediatric Thyroid Carcinoma with the DNA/RNA ThyroSeq v2 Next-Generation Sequencing Assay. Pediatr Dev Pathol 19:115-22
Karunamurthy, Arivarasan; Panebianco, Federica; J Hsiao, Susan et al. (2016) Prevalence and phenotypic correlations of EIF1AX mutations in thyroid nodules. Endocr Relat Cancer 23:295-301
Bogdanova, Tetiana I; Zurnadzhy, Liudmyla Yu; Nikiforov, Yuri E et al. (2015) Histopathological features of papillary thyroid carcinomas detected during four screening examinations of a Ukrainian-American cohort. Br J Cancer 113:1556-64
Dettmer, Matthias S; Perren, Aurel; Moch, Holger et al. (2014) MicroRNA profile of poorly differentiated thyroid carcinomas: new diagnostic and prognostic insights. J Mol Endocrinol 52:181-9
Leeman-Neill, Rebecca J; Kelly, Lindsey M; Liu, Pengyuan et al. (2014) ETV6-NTRK3 is a common chromosomal rearrangement in radiation-associated thyroid cancer. Cancer 120:799-807
Armstrong, Michaele J; Yang, Huaitao; Yip, Linwah et al. (2014) PAX8/PPAR? rearrangement in thyroid nodules predicts follicular-pattern carcinomas, in particular the encapsulated follicular variant of papillary carcinoma. Thyroid 24:1369-74

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