Cyclooxygenase-2 Inhibition, Angiogenesis, Breast Cancer

非甾体类抗炎药（NSAIDs），特别是环氧化酶(COX)-2抑制剂，在预防和治疗癌症方面的作用越来越受到关注。这些药物在降低乳腺癌风险方面的益处已被最近的病例对照、前瞻性和动物研究所证实。非甾体抗炎药抑制COX，将花生四烯酸转化为前列腺素（PG）的酶。COX-1在人乳腺肿瘤、乳腺癌细胞系和啮齿动物乳腺肿瘤中是组成型的，而COX- 2是诱导型和过表达的。新开发的COX-2抑制剂已被证明可以降低啮齿动物结肠和乳腺肿瘤的发病率，并抑制已建立的乳腺肿瘤的生长。虽然作用机制尚不清楚，但这些药物已被证明具有抑制COX酶、减少PG生成、抑制血管生成因子、抑制血管生成的作用。阻断COX可减少小鼠自发性乳腺肿瘤的血管生成。特异性COX-2抑制剂通过调节血管生成来控制乳腺肿瘤生长的能力尚未得到评估。本研究的目的是验证在HER-2/neu过表达小鼠模型中，抑制COX-2通过调节血管生成因子（血管内皮生长因子、碱性成纤维细胞生长因子和血小板衍生生长因子）来调节血管生成，从而降低乳腺肿瘤生长的假设。我们选择HER-2/ new小鼠模型是因为HER-2在30%的乳腺癌中表达，HER-2表达的增加已被证明可上调COX-2。鉴于这一证据，具体目标是：1。评估COX-1和COX-2抑制对乳腺肿瘤生长的影响；2. 检测COX-1和COX-2抑制对血管生成因子表达的影响；3. 探讨COX-1和COX-2抑制对血管生成的影响；4. 通过测定乳腺中免疫细胞（巨噬细胞和淋巴细胞）的存在以及正常小鼠上皮细胞和小鼠肿瘤细胞产生Th-1和Th-2细胞因子和前列腺素的情况，评估COX-1和COX-2抑制对乳腺免疫功能的影响。本研究的结果将确定COX抑制剂作为控制乳腺癌进展的重要治疗策略的作用。

DESCRIPTION (provided by applicant) There is a growing interest in the role of the nonsteroidal anti-inflammatory drugs (NSAIDs), in particular the cyclooxygenase (COX)-2 inhibitors, in the prevention and treatment of cancer. The benefit of these drugs in reducing the risk of breast cancer has been suggested by recent case control, prospective, and animal studies. The NSAIDs inhibit COX, the enzyme that converts arachidonic acid into prostaglandins (PG). The COX-1 form is constitutive while COX 2 is inducible and overexpressed in human breast tumors, breast cancer cell lines, and rodent mammary tumors. The newly developed COX-2 inhibitors have been shown to reduce the incidence of colon and mammary tumors in rodents and inhibit the growth of established mammary tumors. Although the mechanism of action is not clear, these drugs have been shown to inhibit the COX enzyme, reduce PG production, suppress angiogenic factors, and inhibit angiogenesis. Blocking COX reduced angiogenesis in mice with spontaneous mammary tumors. The ability of the specific COX-2 inhibitors to control the growth of mammary tumors by regulating angiogenesis has not been evaluated. The purpose of this study is to test the hypothesis that inhibition of COX-2 reduces the growth of mammary tumors in a mouse model with overexpression of HER-2/neu by regulating angiogenesis through modulation of the angiogenic factors: vascular endothelial growth factor, basic fibroblast growth factor, and platelet- derived growth factor. We have selected the HER-2/neu mouse model because HER-2 is expressed in 30% of all breast cancers and increased HER-2 expression has been shown to upregulate COX-2. In view of this evidence the specific aims are to: 1. evaluate the effect of COX-1 and COX-2 inhibition on the growth of established mammary tumors; 2. examine the effect of COX-1 and COX-2 suppression on the expression of angiogenic factors; 3. investigate the effect of COX-1 and COX-2 inhibition on angiogenesis; 4. evaluate the effect of COX-1 and COX-2 inhibition on immune function in the mammary gland by determining the presence of immune cells (macrophages and lymphocytes) in the mammary gland and the production of Th-1 and Th-2 cytokines and prostaglandins by normal mouse epithelial cells and mouse tumor cells. The results of this study will define the role of COX inhibitors as an important therapeutic strategy in controlling the progression of breast cancer.