BIOLOGICAL SIGNIFICANCE OF PAH AND ESTROGEN-DNA ADDUCTS

PAH 和雌激素-DNA 加合物的生物学意义

• 批准号: 6237043
• 负责人: ELEANOR G ROGAN
• 金额: $ 15.09万
• 依托单位: UNIVERSITY OF NEBRASKA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-05-01 至 1998-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6237043
• 关键词: DNA damage; adduct; animal genetic material tag; carbopolycyclic compound; chemical carcinogenesis; cutaneous papilloma; estrogens; gene mutation; genetic mapping; oncogenes; polymerase chain reaction; tissue /cell culture

The goal on this project is to understand the relationship between carcinogen-DNA adducts, oncogenic mutations and initiation of cancer by polycyclic aromatic hydrocarbons (PAH) and catechol estrogens (CE). We have established a relationship between depurinating DNA adducts, which are released from DNA to leave apurinic sites, and the Harvey (h)-ras mutations exhibited by mouse skin papillomas induced by benzo[alpha]pyrene (BP), dibenzo[alpha,l)pyrene(DB[alpha,l]P), 7,12-dimethylbenz[alpha]anthracene (DMBA) and some of their metabolites. Specifically, depurinating adducts of Ade lead to A yields T transversions at codon 61 in ras and depurinating Gua adducts lead to G yields T transversions in codon 13. Presumably, the mutations are a consequence of mis-repaired apurinic sites generated by the loss of the depurinating adducts. Endogenous CE, metabolites of estrone (E1) and 17beta-estradiol (E2) that we hypothesize to be procarcinogens, can be oxidized to CE quinones (CE-Q) and bind to DNA. CE-3,4-Q form depurinating N7Gua adducts in abundance, generating apurinic sites in the DNA, which in vivo could be misrepaired to yield oncogenic mutations. To gain further evidence that H-ras mutations arise from depurinating adducts formed by PAH and CE-Q and to increase our understanding of sequence specificity in the formation of stable adducts and apurinic sits, we propose to (1) determine the H-ras mutations in mouse skin papillomas induced by selected PAH and correlate the mutations with adducts; (2) investigate whether H-ras mutations can be detected in preneoplastic mouse skin treated with DB[alpha l)P or DB[alphal]P-11,12-dihydrodiol; (3) analyze the stable and depurinating adducts formed in 18-bp oligonucleotides by treatment with CE-Q; (4) identify the nature of the DNA lesions (i.e., stable adducts or apurinic sites) in (a) a 231 base-pair region of pBR322 DFNA and (b) the exon 1 and 2 region (547 base-pairs) of c-H-ras induced by treatment with BPDE, DB[alphal]PDE, CE-Q or peroxidase- activated BP, DB[alpha,l]P or CE; and (5) analyze the mutations induced in the supF gene replicated by a HeLa cell extract after treatment with BPDE, DB[alpha,l]PDE, CE-Q or peroxidase-activated BP, DB[alpha,l]P or CE. The results of these studies will provide us with detailed knowledge of the reaction of the selected PAH and CE-Q with DNA to generate apurinic sites, stable adducts and oncogenic mutations.

该项目的目标是了解 致癌基因加合物，致癌突变和癌症开始 多环芳烃（PAH）和儿茶酚雌激素（CE）。 我们 已经建立了脱离DNA加合物之间的关系 从DNA释放以留下Apurinic位点，Harvey（H）-RAS突变 由苯并[alpha] pyrene（bp）诱导的小鼠皮肤乳头状瘤展示 dibenzo [alpha，l）pyrene（db [alpha，l] p），7,12-二甲基苯子[alpha]蒽 （DMBA）及其一些代谢产物。 具体而言，脱离加合物 ADE导致在RAS中的密码子61处产生t termanters trable thuting GUA加合物导致g产生密码子13中的T横向。大概， 突变是由误导的源泉位点产生的错误的结果 脱离加合物的丧失。 内源性CE，雌酮的代谢产物 （E1）和17beta-雌二醇（E2），我们假设是procarcinogens， 可以氧化为CE Quinones（CE-Q）并与DNA结合。 CE-3,4-Q形式 在丰富的n7gua加合物中驱逐出现，在 DNA，体内可能被误导以产生致癌突变。 到 获得进一步的证据，表明H-RAS突变是由降低加合物引起的 由PAH和CE-Q组成，并增加我们对序列的理解 在稳定加合物和昆虫形成的特异性中，我们 提议（1）确定小鼠皮肤乳头状瘤中的H-RAS突变 通过选定的PAH诱导并将突变与加合物相关联； （2） 研究是否可以在前塑性小鼠中检测到H-RAS突变 用db [alpha l）P或dB [alphal] P-11,12-二氢二醇处理的皮肤； （3） 分析在18 bp中形成的稳定和降低的加合物 通过使用CE-Q处理寡核苷酸； （4）识别DNA的性质 （a）231碱基对的病变（即稳定的加合物或座位位点） PBR322 DFNA和（b）外显子1和2区（547个碱基对）的区域 通过BPDE，DB [alphal] PDE，CE-Q或过氧化物酶 - 诱导的C-H-RAS 活化的BP，DB [Alpha，L] P或CE； （5）分析诱导的突变 用BPDE处理后，由HeLa细胞提取物复制的SUPF基因， DB [Alpha，L] PDE，CE-Q或过氧化物酶激活的BP，DB [Alpha，L] P或CE。 这 这些研究的结果将为我们提供有关 选定的PAH和CE-Q与DNA的反应以产生源自位点， 稳定的加合物和致癌突变。