MECHANISM OF GLUCARATE INHIBITION OF MAMMARY CANCER

这项提议的主要目标将是检验这一假设 β-葡萄糖醛酸酶抑制剂D-葡萄糖苷的形成- 从D-葡萄糖酸钙中提取的1，4-内酯(1，4-GL)是至关重要的 D-葡萄糖酸抑制乳腺癌的作用机制 1，4-GL介导的促乳房激素水平和DNA的调节 合成至少在一定程度上对这种强大的 D-葡萄糖酸酯的化学预防作用。久经考验的 黄曲霉毒素诱发雌性SD大鼠乳腺癌变 单人S.C.将使用剂量的N-甲基亚硝脲(MNU)。特定的 目标包括：(一)建立D-葡萄糖酸中的 酸/D-葡萄糖酸/D-葡萄糖内酯家族，1，4-GL是终极 通过检测其在MNU诱导的小鼠体内致癌作用的研究 大鼠乳腺癌变模型，应用非β-抑制物 6，3-内酯(6，3-GL)为阴性对照。在……里面 为了克服已知的1，4-GL在体内的不稳定性，一些 将使用1，4-GL和6，3GL的衍生物。不同 这些衍生品的浓度将被合并到半 精制AIN-76A日粮。修改后的饲料将喂给大鼠 从MNU后一周开始持续，以避免任何饮食影响 印心前乳腺的发育。建议的角色 将进一步确认D-葡萄糖酸钙作为1，4-GL的前体 通过对阿司匹林的代谢、药代动力学和药物处置的研究 非放射性和~(14)C标记D-葡萄糖酸钙在大鼠体内的研究 化合物。(2)确定“公约”的系统和局部影响 1，4-甘氨酸甘油酯，连续饲喂幼年雌性SD大鼠 在MNU治疗前早期，即在促乳房激素水平上， 雌激素受体与不同年龄组乳腺的增殖状态 时间点，以及最终的致瘤反应。一种组合 胸腺嘧啶核苷放射自显影和免疫组织化学染色 β-葡萄糖醛酸苷酶或雌激素受体，将被用来研究 β-葡萄糖醛酸苷酶与雌激素受体的潜在相关性 表达和DNA合成。(Iii)证明荷尔蒙 置换对大鼠D-葡萄糖基-1，4-内酯抑制无影响 乳腺癌。MNU诱导的大鼠乳腺肿瘤将被 切除脑下垂体并用雌二醇和催乳素或赋形剂治疗， 同时饲喂添加和不添加D-葡聚糖-1，4-内酯的饲料。的变化 肿瘤的大小将与激素受体状态相关。

The primary objective of this proposal will be to test the hypothesis that formation of the beta-glucuronidase inhibitor, D-glucaro- 1,4-lactone (1,4-GL) from calcium D-glucarate, is of critical importance for the mechanism of D-glucarate inhibition of mammary cancer and that 1,4-GL-mediated modulation of mammotropic hormone levels and DNA synthesis is at least partially responsible for the potent chemopreventive effect of D-glucarate. The well established model of mammary carcinogenesis induced in female Sprague-Dawley rats with a single s.c. dose of N-methylnitrosourea (MNU) will be used. Specific Aims include: (i) Establishment of the theory that in D-glucaric acid/D-glucarate/D-glucarolactones family, 1,4-GL is the ultimate inhibitor of carcinogenesis by testing its efficacy in the MNU-induced rat mammary carcinogenesis model, with a non-inhibitor of beta- glucuronidase, D-glucaro-6,3-lactone (6,3-GL) as negative control. In order to overcome the known instability of 1,4-GL in vivo, some derivatives of 1,4-GL and 6,3GL will be utilized. Different concentrations of these derivatives will be incorporated to the semi- purified AIN-76A diet. The modified diets will be fed to rats continually beginning one week after MNU to avoid any dietary effects on the development of mammary gland prior to initiation. The suggested role of calcium D-glucarate as a precursor of 1,4-GL will be further confirmed by investigation of the metabolism, pharmacokinetics and disposition of calcium D-glucarate in the rat using both non-radioactive and 14C-labeled compounds. (ii) Determination of the systemic and local effects of 1,4-GL, fed continually to young female Sprague-Dawley rats beginning early before MNU treatment, i.e. on mammotropic hormones levels, the estrogen receptor and proliferative status of mammary gland at different time-points, and on the final tumorigenic response. A combination of [3H]thymidine autoradiography and immunohistochemical staining for beta-glucuronidase or estrogen receptor, will be used to investigate a potential correlation between B-glucuronidase and or estrogen receptor expression and DNA synthesis. (iii) Demonstration that hormone replacement has no effect on D-glucaro-1,4-lactone inhibition of rat mammary cancer. The rats with MNU-induced mammary tumors will be hypophysectomized and treated with estradiol and prolactin or vehicle, while fed diets with and without D-glucaro- 1,4-lactone. Changes in the size of tumors will be correlated with the hormone receptor status.