Polycyclic Hydrocarbons and CYP1B1 in Breast Cancer

乳腺癌中的多环烃和 CYP1B1

• 批准号: 6633797
• 负责人: COLIN ROBERT JEFCOATE
• 金额: $ 27.55万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-04-01 至 2006-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6633797
• 关键词: DNA damage; adduct; aromatic hydrocarbon receptor; breast neoplasms; carbopolycyclic compound; carcinogen testing; chemical carcinogen; chemical carcinogenesis; clinical research; cytochrome P450; drug metabolism; enzyme activity; epithelium; female; gene targeting; genetically modified animals; human subject; integrins; laboratory mouse; mutagen testing; mutagens; receptor binding; women's health

DESCRIPTION: (Adapted from the Applicant's Abstract): Many PAHs are potent mammary carcinogens in rodent models, but their role in human breast cancer is poorly understood. We have cloned cytochrome P4501B1 (CYP1B1) and have shown that CYP1B 1-null mice are resistant to several cancers, which are induced by PAHs in normal mice. We will test the hypothesis that CYP1B 1 plays a major role in PAH-induced breast cancer, and that the contribution is greater than for CYP1A1 for one or more of the following reasons: (1) CYP1B1 is constitutively expressed in breast epithelia, whereas CYP1A1 requires induction by the PAH, via the Ah-receptor (AhR); (2) CYP1B1, which is also via the AhR, is expressed in multiple breast cell types, including luminal and basal epithelia and a highly proliferative progenitor cell population that may be very susceptible to transformation. CYP1A1 is primarily expressed in more differentiated luminal epithelia; (3) PAHs are preferentially metabolized to carcinogenic dihydrodiol epoxides (PAHDE) by CYP1B1 relative to CYP1A1. Human primary breast epithelia from reduction mammoplasty tissues will be resolved into the respective cell types. The PAHs to be examined are: dibenzo[a,l]pyrene (diBP), representative of the most potent fjord class; benzo[a]pyrene (BP), a bay-region PAH; and 7,12-dimethylbenz[a]anthracene (DMBA), a pseudo-fjord PAR. Metabolism and PAHIDE-DNA adduct formation will be analyzed in mice (wild type and CYP1B 1-null) in vivo in relation to mammary cancer development following BP, DMBA, and diBP exposure. Similar metabolic analyses will be completed in separated primary human breast epithelia for comparison of CYP1B1 and CYP1A1 expression and AhR activation. The role of CYP1B 1 will be further defined by anti-sense suppression or over-expression in the near normal human breast epithelial cell line, MCF-10F. These metabolically activated PAHs cause growth arrest at low concentrations. We will identify markers of this response, and we will examine the role of CYP1B1 in PAHDE-DNA adduct formation. The transformation of MCF-10F cells (including expression variants) to cells that form anchorage-independent colonies will be used to test the involvement of CYP1B 1 in these changes, which correlate with the early stages of carcinogenesis. This work will examine PAR activation for the first time in well characterized primary human breast cells that are cultured to replicate in vivo ductal morphology. The correlation with CYP1B 1 expression and activity will provide insight into the relationship of the mouse model to human breast cancer.

描述：（改编自申请人的摘要）：许多PAH是有效的 啮齿动物模型中的乳腺致癌物，但它们在人类乳腺癌中的作用是 理解不佳。我们已经克隆了细胞色素P4501B1（CYP1B1），并显示了 CYP1B 1-NULL小鼠对几种癌症具有抗性，这些癌症由 正常小鼠的PAH。我们将测试CYP1B 1发挥主要作用的假设 在PAH引起的乳腺癌中的作用，并且贡献大于 对于CYP1A1，出于以下一个或多个原因：（1）CYP1B1为 在乳房上皮中的组成型表达，而CYP1A1需要诱导 通过PAH，通过AH-受体（AHR）； （2）CYP1B1，也是通过AHR的 以多种乳腺细胞类型表示，包括腔和基础 上皮和高度增殖的祖细胞群可能是 非常容易转化。 CYP1A1主要在更多中表达 分化的腔上皮； （3）PAH优先代谢为 CYP1B1相对于CYP1A1，致癌二氢二醇环氧化物（PAHDE）。人类 还可以分辨出还原性乳房成形术组织的原发性乳房上皮 进入各自的细胞类型。要检查的PAH是：dibenzo [a，l] pyrene （dibp），最有效的峡湾类的代表； Benzo [a] pyrene（bp），a 湾区PAH；和7,12-二甲基苯甲酸[a]蒽（DMBA），伪峡湾。 将在小鼠（野生型）中分析代谢和Pahide-DNA加合物形成 和CYP1B 1-NULL）在体内与乳腺癌发展有关 BP，DMBA和DIBP暴露。类似的代谢分析将在 分离的原发性人乳房上皮用于比较CYP1B1和CYP1A1 表达和AHR激活。 CYP1B 1的作用将进一步定义 在人类近乎正常的人乳房中的反义抑制或过表达 上皮细胞系，MCF-10F。这些代谢激活的PAH会导致生长 低浓度逮捕。我们将确定此回应的标记，我们 将检查CYP1B1在PAHDE-DNA加合物形成中的作用。这 MCF-10F细胞（包括表达变体）转换为细胞 形式与锚固无关的菌落将用于测试参与 CYP1B 1在这些变化中，这与早期阶段相关 致癌作用。这项工作将首次检查par激活 具有培养以复制的原代人乳房细胞的特征良好 体内导管形态。与CYP1B 1表达和活性的相关性 将提供有关小鼠模型与人乳房关系的洞察力 癌症。