title: CLIP2 as radiation biomarker in papillary thyroid carcinoma.
abstract: A substantial increase in papillary thyroid carcinoma (PTC) among children exposed to the radioiodine fallout has been one of the main consequences of the Chernobyl reactor accident. Recently, the investigation of PTCs from a cohort of young patients exposed to the post-Chernobyl radioiodine fallout at very young age and a matched nonexposed control group revealed a radiation-specific DNA copy number gain on chromosomal band 7q11.23 and the radiation-associated mRNA overexpression of CLIP2. In this study, we investigated the potential role of CLIP2 as a radiation marker to be used for the individual classification of PTCs into CLIP2-positive and -negative cases-a prerequisite for the integration of CLIP2 into epidemiological modelling of the risk of radiation-induced PTC. We were able to validate the radiation-associated CLIP2 overexpression at the protein level by immunohistochemistry (IHC) followed by relative quantification using digital image analysis software (P=0.0149). Furthermore, we developed a standardized workflow for the determination of CLIP2-positive and -negative cases that combines visual CLIP2 IHC scoring and CLIP2 genomic copy number status. In addition to the discovery cohort (n=33), two independent validation cohorts of PTCs (n=115) were investigated. High sensitivity and specificity rates for all three investigated cohorts were obtained, demonstrating robustness of the developed workflow. To analyse the function of CLIP2 in radiation-associated PTC, the CLIP2 gene regulatory network was reconstructed using global mRNA expression data from PTC patient samples. The genes comprising the first neighbourhood of CLIP2 (BAG2, CHST3, KIF3C, NEURL1, PPIL3 and RGS4) suggest the involvement of CLIP2 in the fundamental carcinogenic processes including apoptosis, mitogen-activated protein kinase signalling and genomic instability. In our study, we successfully developed and independently validated a workflow for the typing of PTC clinical samples into CLIP2-positive and CLIP2-negative and provided first insights into the CLIP2 interactome in the context of radiation-associated PTC.
authors.affiliation: Research Unit Radiation Cytogenetics, Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, Neuherberg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Selmansberger
authors.affiliation: Research Unit Analytical Pathology, Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, Neuherberg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Feuchtinger
authors.affiliation: Institute of Endocrinology and Metabolism, National Academy of Medical Sciences of the Ukraine, Kiev, Ukraine.
authors.forename: L
authors.initials: L
authors.lastname: Zurnadzhy
authors.affiliation: Research Unit Radiation Cytogenetics, Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, Neuherberg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Michna
authors.affiliation: Institute of Radiation Protection, Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, Neuherberg, Germany.
authors.forename: J C
authors.initials: JC
authors.lastname: Kaiser
authors.affiliation: Bundeswehr Institute of Radiobiology, Munich, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Abend
authors.affiliation: Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, NCI, Bethesda, MD, USA.
authors.forename: A
authors.initials: A
authors.lastname: Brenner
authors.affiliation: Institute of Endocrinology and Metabolism, National Academy of Medical Sciences of the Ukraine, Kiev, Ukraine.
authors.forename: T
authors.initials: T
authors.lastname: Bogdanova
authors.affiliation: Research Unit Analytical Pathology, Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, Neuherberg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Walch
authors.affiliation: Research Unit Radiation Cytogenetics, Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, Neuherberg, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Unger
authors.affiliation: Research Unit Radiation Cytogenetics, Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, Neuherberg, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Zitzelsberger
authors.affiliation: Research Unit Radiation Cytogenetics, Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, Neuherberg, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Hess
mesh_terms: D000293:Adolescent; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002291:Carcinoma, Papillary / Q000378:metabolism*; D016022:Case-Control Studies; D047852:Chernobyl Nuclear Accident; D002648:Child; D002675:Child, Preschool; D004781:Environmental Exposure; D053263:Gene Regulatory Networks; D006801:Humans; D007223:Infant; D007457:Iodine Radioisotopes / Q000633:toxicity; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D009381:Neoplasms, Radiation-Induced / Q000378:metabolism*; D011847:Radioactive Fallout; D013964:Thyroid Neoplasms / Q000378:metabolism*; D014455:Ukraine
chemical_list: D014408:Biomarkers, Tumor; D007457:Iodine Radioisotopes; D008869:Microtubule-Associated Proteins; D011847:Radioactive Fallout; C109878:cytoplasmic linker protein 115