title: DNA topoisomerases participate in fragility of the oncogene RET.
abstract: Fragile site breakage was previously shown to result in rearrangement of the RET oncogene, resembling the rearrangements found in thyroid cancer. Common fragile sites are specific regions of the genome with a high susceptibility to DNA breakage under conditions that partially inhibit DNA replication, and often coincide with genes deleted, amplified, or rearranged in cancer. While a substantial amount of work has been performed investigating DNA repair and cell cycle checkpoint proteins vital for maintaining stability at fragile sites, little is known about the initial events leading to DNA breakage at these sites. The purpose of this study was to investigate these initial events through the detection of aphidicolin (APH)-induced DNA breakage within the RET oncogene, in which 144 APH-induced DNA breakpoints were mapped on the nucleotide level in human thyroid cells within intron 11 of RET, the breakpoint cluster region found in patients. These breakpoints were located at or near DNA topoisomerase I and/or II predicted cleavage sites, as well as at DNA secondary structural features recognized and preferentially cleaved by DNA topoisomerases I and II. Co-treatment of thyroid cells with APH and the topoisomerase catalytic inhibitors, betulinic acid and merbarone, significantly decreased APH-induced fragile site breakage within RET intron 11 and within the common fragile site FRA3B. These data demonstrate that DNA topoisomerases I and II are involved in initiating APH-induced common fragile site breakage at RET, and may engage the recognition of DNA secondary structures formed during perturbed DNA replication.
authors.affiliation: Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, North Carolina, United States of America.
authors.forename: Laura W
authors.initials: LW
authors.lastname: Dillon
authors.forename: Levi C T
authors.initials: LC
authors.lastname: Pierce
authors.forename: Christine E
authors.initials: CE
authors.lastname: Lehman
authors.forename: Yuri E
authors.initials: YE
authors.lastname: Nikiforov
authors.forename: Yuh-Hwa
authors.initials: YH
authors.lastname: Wang
mesh_terms: D016590:Aphidicolin / Q000494:pharmacology; D001483:Base Sequence; D002460:Cell Line; D004247:DNA / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D053960:DNA Breaks / Q000187:drug effects; D004261:DNA Replication / Q000187:drug effects; D004264:DNA Topoisomerases, Type I / Q000378:metabolism*; D004250:DNA Topoisomerases, Type II / Q000378:metabolism*; D006801:Humans; D007438:Introns / Q000235:genetics; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation / Q000187:drug effects; D009857:Oncogenes; D059748:Proteolysis / Q000187:drug effects; D051096:Proto-Oncogene Proteins c-ret / Q000235:genetics*; D059003:Topoisomerase Inhibitors / Q000494:pharmacology
chemical_list: D059003:Topoisomerase Inhibitors; D016590:Aphidicolin; D004247:DNA; D051096:Proto-Oncogene Proteins c-ret; D004264:DNA Topoisomerases, Type I; C528909:TOP1 protein, human; D004250:DNA Topoisomerases, Type II
references.citation: Cancer. 2009 Aug 15;115(16):3801-7
references.pmid: 19598221
references.citation: Proc Natl Acad Sci U S A. 2008 Jan 8;105(1):246-51
references.pmid: 18162546
references.citation: J Nat Prod. 2009 Sep;72(9):1643-50
references.pmid: 19691293
references.citation: Cell Cycle. 2011 Feb 15;10(4):611-8
references.pmid: 21293182
references.citation: Genomics. 1997 Jun 1;42(2):252-9
references.pmid: 9192845
references.citation: Hum Genet. 1984;67(2):136-42
references.pmid: 6430783
references.citation: Cytogenet Genome Res. 2003;100(1-4):77-84
references.pmid: 14526166
references.citation: Mol Cell. 2011 Dec 23;44(6):966-77
references.pmid: 22195969
references.citation: Hum Mol Genet. 1995 Dec;4(12):2313-8
references.pmid: 8634704
references.citation: J Pediatr Surg. 1984 Dec;19(6):855-60
references.pmid: 6097662
references.citation: Nat Med. 2012 Feb 12;18(3):378-81
references.pmid: 22327623
references.citation: Cancer Res. 1989 May 15;49(10):2578-83
references.pmid: 2540903
references.citation: Clin Cancer Res. 2002 Mar;8(3):641-61
references.pmid: 11895891
references.citation: Oncogene. 1992 Jul;7(7):1331-7
references.pmid: 1620547
references.citation: Nat Rev Mol Cell Biol. 2011 Nov 23;12(12):827-41
references.pmid: 22108601
references.citation: Cancer Epidemiol Biomarkers Prev. 2009 Mar;18(3):784-91
references.pmid: 19240234
references.citation: Mol Cell Biol. 2003 Oct;23(20):7143-51
references.pmid: 14517285
references.citation: Hum Mol Genet. 2013 Apr 1;22(7):1443-56
references.pmid: 23297364
references.citation: J Biol Chem. 1994 Jan 21;269(3):2068-74
references.pmid: 8294458
references.citation: Acta Oncol. 1994;33(6):591-8
references.pmid: 7946433
references.citation: Genome Res. 2004 Jul;14(7):1350-7
references.pmid: 15231750
references.citation: J Biol Chem. 1994 Mar 11;269(10):7719-25
references.pmid: 8125998
references.citation: Nat Rev Cancer. 2006 Apr;6(4):292-306
references.pmid: 16557281
references.citation: Br J Cancer. 1993 Nov;68(5):1006-11
references.pmid: 8217588
references.citation: Proc Natl Acad Sci U S A. 1998 Jul 7;95(14):8141-6
references.pmid: 9653154
references.citation: Nat Rev Mol Cell Biol. 2002 Jun;3(6):430-40
references.pmid: 12042765
references.citation: Cancer Res. 2002 Jun 15;62(12):3477-84
references.pmid: 12067991
references.citation: J Clin Endocrinol Metab. 2005 Apr;90(4):2364-9
references.pmid: 15671095
references.citation: Expert Rev Mol Diagn. 2008 Jan;8(1):83-95
references.pmid: 18088233
references.citation: Curr Genomics. 2010 Aug;11(5):326-37
references.pmid: 21286310
references.citation: Mol Cell Biol. 2000 Jun;20(12):4420-7
references.pmid: 10825205
references.citation: EMBO J. 2007 Feb 21;26(4):998-1009
references.pmid: 17290216
references.citation: Biochim Biophys Acta. 1998 Oct 1;1400(1-3):185-94
references.pmid: 9748568
references.citation: Acta Oncol. 2008;47(3):469-72
references.pmid: 18348005
references.citation: Nat Cell Biol. 2009 Nov;11(11):1315-24
references.pmid: 19838172
references.citation: Chem Biodivers. 2005 May;2(5):689-94
references.pmid: 17192012
references.citation: J Mol Biol. 1984 Dec 15;180(3):515-31
references.pmid: 6098684
references.citation: Cancer Lett. 2006 Jan 28;232(1):4-12
references.pmid: 16229941
references.citation: Nat Rev Endocrinol. 2011 Aug 30;7(10):569-80
references.pmid: 21878896
references.citation: Endocr Pathol. 2002 Spring;13(1):3-16
references.pmid: 12114746
references.citation: Nucleic Acids Res. 2003 Jul 1;31(13):3406-15
references.pmid: 12824337
references.citation: Chromosome Res. 2000;8(8):677-88
references.pmid: 11196131
references.citation: Br J Cancer. 1989 Dec;60(6):897-903
references.pmid: 2557880
references.citation: Nucleic Acids Res. 2010 Mar;38(4):1149-62
references.pmid: 19969545
references.citation: Cancer Res. 2007 Dec 15;67(24):11848-58
references.pmid: 18089815
references.citation: Mol Pharmacol. 2000 Jul;58(1):71-81
references.pmid: 10860928
references.citation: Nat Rev Cancer. 2005 Dec;5(12):943-55
references.pmid: 16294218
references.citation: Oncogene. 1999 Nov 4;18(46):6330-4
references.pmid: 10597232
references.citation: Annu Rev Genet. 2007;41:169-92
references.pmid: 17608616
references.citation: DNA Repair (Amst). 2010 Jun 4;9(6):678-89
references.pmid: 20413351
references.citation: J Natl Cancer Inst. 1997 Oct 1;89(19):1429-39
references.pmid: 9326912
references.citation: Hum Mol Genet. 1998 Apr;7(4):755-61
references.pmid: 9499431
references.citation: Nucleic Acids Res. 2008 Nov;36(19):6165-74
references.pmid: 18824478
references.citation: J Biol Chem. 1998 Jul 10;273(28):17643-50
references.pmid: 9651360
references.citation: Nucleic Acids Res. 2011 Mar;39(5):1749-62
references.pmid: 21051337
references.citation: Nature. 2010 Feb 18;463(7283):893-8
references.pmid: 20164919
references.citation: J Biol Chem. 1979 Nov 25;254(22):11495-504
references.pmid: 227871
references.citation: Oncogene. 2010 Apr 15;29(15):2272-80
references.pmid: 20101222
references.citation: Mol Cell. 2007 Aug 3;27(3):367-79
references.pmid: 17679088
references.citation: J Pediatr Surg. 1993 Oct;28(10):1342-8; discussion 1348-9
references.pmid: 8263699
references.citation: J Pediatr Surg. 2003 Nov;38(11):1574-80
references.pmid: 14614703
references.citation: Biochemistry. 1993 Aug 24;32(33):8568-74
references.pmid: 8395209
references.citation: BMC Genomics. 2009 Jan 30;10:59
references.pmid: 19183484
references.citation: Cytogenet Genome Res. 2007;118(2-4):260-9
references.pmid: 18000379
references.citation: Cytogenet Genome Res. 2008;121(3-4):196-200
references.pmid: 18758159
references.citation: J Korean Med Sci. 2008 Feb;23(1):149-52
references.pmid: 18303218
references.citation: Br J Cancer. 1999 Apr;79(11-12):1884-93
references.pmid: 10206309
references.citation: Cancer Res. 1985 Jul;45(7):3106-12
references.pmid: 3839166
references.citation: Cell. 1982 Apr;28(4):767-79
references.pmid: 6178514
references.citation: Cell. 2005 Aug 12;122(3):365-78
references.pmid: 16096057
references.citation: Proc Natl Acad Sci U S A. 2010 Jan 12;107(2):692-7
references.pmid: 20080737
references.citation: Nucleic Acids Res. 1984 Apr 11;12(7):3097-114
references.pmid: 6326051
references.citation: Nucleic Acids Res. 1997 Oct 15;25(20):4111-6
references.pmid: 9321666
references.citation: Proc Natl Acad Sci U S A. 1987 Oct;84(20):7024-7
references.pmid: 2823250
references.citation: Nat Med. 2012 Feb 12;18(3):375-7
references.pmid: 22327624
references.citation: Cell. 1988 May 6;53(3):433-40
references.pmid: 2835168
references.citation: Nucleic Acids Res. 2007;35(16):5351-9
references.pmid: 17693431
references.citation: Proc Natl Acad Sci U S A. 2001 Jul 17;98(15):8219-26
references.pmid: 11459956
references.citation: Genomics. 2001 Apr 15;73(2):149-60
references.pmid: 11318605