Prevention of UV-induced carcinogenesis by cyanidin-3-glucoside

描述（由申请人提供）：流行病学、临床和实验室研究表明，紫外线辐射（UV）是一种完全的环境致癌物，反复暴露可导致黑色素瘤和非黑色素瘤皮肤癌的发展。除了防晒霜，天然无毒化合物的化学预防皮肤癌被认为是预防皮肤癌发生的有效策略。我们对黑莓和其他食物中发现的化合物氰苷-3-葡萄糖苷（C3G）的体外和体内研究表明，该化合物能够抑制NF-:B、AP-1、COX2和TNF1的激活/表达、肿瘤转化、癌细胞迁移和侵袭以及诱导HL60细胞凋亡。C3G还通过抑制活性氧的产生和诱导抗氧化调节转录因子发挥抗氧化剂的作用。这些初步研究表明，C3G可能是一种潜在的化学预防和化学治疗药物。该应用的总体假设是C3G作为抗氧化剂，抑制氧化应激、转录因子的激活和炎症信号蛋白，从而防止uvb诱导的致癌作用。具体目标C3G抗氧化性能的体内外实验研究。电子自旋共振（ESR）自旋捕获将用于确定C3G在非细胞系统中对羟基（7OH）和超氧化物（O27-）自由基的反应速率，以Fenton反应（Fe(II) + H2O2）和黄嘌呤/黄嘌呤氧化酶作为这些自由基的来源，并研究在细胞系统中对uva诱导的7OH和O27-自由基的抗氧化活性。低频（体内）ESR也将用于研究C3G对uvb产生的SKH-1无毛小鼠皮肤中O27-和7OH自由基的抗氧化活性。具体目标2。C3G对uvb诱导的氧化应激及氧化应激敏感转录因子激活作用的体内研究我们将研究C3G对uvb诱导的KSH小鼠脂质过氧化、蛋白质氧化和氧化性DNA损伤的影响。我们还将研究C3G对uvb诱导的转基因小鼠活化蛋白(AP)-1、核因子(NF)-:B和活化T细胞核因子（NAFT）活化的影响。具体目标3。探讨C3G对uvb诱导炎症介质的影响。这些炎症介质包括浸润性白细胞和髓过氧化物酶（MPO）、COX-2、PGE2和几种促炎细胞因子，如TNF-1、IL-2和IL-6。具体目标C3G对uvb诱导的肿瘤发生及早期生物标志物影响的研究。这些标记包括胸腺嘧啶阳性细胞、增殖细胞核抗原、末端脱氧核苷酸转移酶介导的dUTP缺口末端标记、凋亡细胞以及表皮中p53和p21/cip1阳性细胞群的变化。这些研究将为C3G在皮肤癌预防中的早期功效提供一个机制基础。

DESCRIPTION (provided by applicant): Epidemiological, clinical, and laboratory studies have implicated that ultraviolet radiation (UV) is a complete environmental carcinogen and that repeated exposures can lead to the development of melanoma and nonmelanoma skin cancers. In addition to sunscreens, chemoprevention of skin cancer by natural non-toxic compounds is suggested as an effective strategy to prevent the incidence of skin cancer. Our in vitro and in vivo studies on cyanidin-3-glucoside (C3G), a compound found in blackberries and other foods, show that this compound is able to inhibit NF-:B, AP-1, COX2, and TNF1 activation/expression, neoplastic transformation, cancer cell migration and invasion, and induction of apoptosis in HL60 cells. C3G also functions as an antioxidant by inhibiting the generation of reactive oxygen species and inducing antioxidant-regulative transcription factors. These preliminary studies indicate that C3G may function as a potential chemopreventive and chemotherapeutic agent. The overall hypothesis of this application is that C3G functions as an antioxidant and inhibits oxidative stress, activation of transcription factors, and inflammatory signaling proteins, leading to protection against UVB-induced carcinogenesis. Specific Aim 1. In vitro and in vivo investigation of antioxidant properties of C3G. Electron spin resonance (ESR) spin trapping will be used to determine the reaction rates of C3G toward hydroxyl (7OH) and superoxide (O27-) radicals, using Fenton reaction (Fe(II) + H2O2) and xanthine/xanthine oxidase as sources of these free radicals in a non-cellular system, and to investigate antioxidant activities against UVB-induced 7OH and O27- radicals in a cellular system. Low frequency (in vivo) ESR will be also used to study antioxidant activities of C3G against UVB-generated O27- and 7OH radicals in the skin of SKH-1 hairless mice. Specific Aim 2. In vivo investigation of the effects of C3G on UVB-induced oxidative stress and activation of oxidative stress sensitive transcription factors. We will investigate the effects of C3G on UVB-induced lipid peroxidation, protein oxidation, and oxidative DNA damage in KSH mice. We will also study the effects of C3G on UVB-induced activation of activation protein (AP)-1, nuclear factor (NF)-:B, and nuclear factor of activated T cells (NAFT) in transgenic mice. Specific Aim 3. Investigate the effects of C3G on UVB-induced inflammatory mediators. These inflammatory mediators include infiltrating leukocytes and myeloperoxidase (MPO), COX-2, PGE2, and several pro-inflammatory cytokines, TNF-1, IL-2, and IL-6. Specific Aim 4. Investigation of the effects of C3G on UVB-induced tumorigenesis and early biomarkers. These markers include changes in thymine-positive cells, proliferative cell nuclear antigen, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling, and apoptotic cells together with a change in p53 and p21/cip1- positive cell population in epidermis. These studies will provide a mechanistic rationale for an early on C3G efficacy in skin cancer prevention. PUBLIC HEALTH RELEVANCE: The incidence of UV-induced skin cancer is a major public health concern. Present study attempts to identify cyanidin-3-glucoside, a plant-derived compound, as a mechanism-based preventive agent against UV-induced skin cancers.