Inhibition of Rat Oral Carcinogenesis by Dietary Black Raspberries

描述(由申请人提供)：流行病学数据表明，经常食用新鲜水果和蔬菜与口腔癌风险降低之间存在很强的相关性。为了支持这些数据，临床前研究表明，黑树莓(BRBs)具有显著的能力，可以防止动物的呼吸道肿瘤的发展，包括口腔(仓鼠)、食道(大鼠)和结肠(大鼠)。此外，我们正在进行的I期临床试验已经证明，BRBs能够以一种支持口腔癌化学预防策略的方式来调节分子疗效的炎性生物标志物。从这些人类临床试验中，我们已经建立了临床相关的、口腔粘膜来源的、BRB反应的生物标记物的新的分子标记。要阐明BRB介导的口腔化学预防的潜在基础和预防人类口腔癌发展的预测效果，将需要进一步使用具有足够分子试剂的合适的动物模型。虽然仓鼠颊囊模型有成功识别具有防癌活性的化学物质和食物(包括BRBs)的历史，但由于缺乏仓鼠基因组信息，以及随后缺乏深入系统生物学研究的试剂和工具，探索性和比较分子研究受到阻碍。因此，必须采用另一种合适的口腔癌动物模型。大鼠舌头/4NQO口腔癌变系统为研究黑树莓介导的口腔化学预防提供了一个成熟的模型。目前的方案将利用大鼠舌头模型来探索BRBs抑制口腔癌的能力。 并将BRBs在大鼠舌头中的分子功效与在人类口腔肿瘤和高危黏膜中的分子功效进行了比较。我们假设BRBs中的生物活性成分将抑制肿瘤的形成，并减少与口腔癌相关的临床相关的促炎分子生物标记物的表达。以下具体目标独特地结合了营养、分子疗效和癌症预防等方面来解决提出的假设。在特定目标1中提出的研究将确定饮食BRBs或单一BRB生物活性成分(鞣花酸；EA)在4NQO诱导的F344大鼠口腔癌变过程中抑制舌部病变形成的能力。在《特定目标2》中提出的研究将确定BRBs和EA在大鼠舌癌发生中的比较分子疗效，使用与临床相关的转录图谱，这些基因以前在口腔癌患者的肿瘤和高危口腔粘膜细胞中被BRBS调节。随着上述特定目标的成功完成，我们的新研究将(I)确定饮食中brb在口腔癌大鼠模型中的化学预防潜力，(Ii) 验证BRB在大鼠口腔粘膜中与人类口腔癌直接相关的分子疗效的特征，并(Iii)为未来口腔癌化学预防的机制研究提供基础。

DESCRIPTION (provided by applicant): Epidemiological data demonstrate a strong correlation between frequent consumption of fresh fruits and vegetables and a decreased risk of oral cancer. In support of these data, preclinical studies have demonstrated the remarkable ability of black raspberries (BRBs) to prevent the development of aerodigestive tract tumors in animals, including oral (hamsters), esophagus (rat), and colon (rats). Furthermore, our ongoing Phase I clinical trials have demonstrated the ability of BRBs to modulate inflammatory biomarkers of molecular efficacy in a manner that supports a chemopreventive strategy for oral cancer. From these human clinical trials, we have established a novel molecular signature of clinically relevant, oral mucosa-derived, BRB-responsive biomarkers. Efforts to elucidate the underlying basis of BRB-mediated oral chemoprevention and predictive efficacy to prevent human oral cancer development will require further employment of a suitable animal model with sufficient molecular reagents. While the hamster cheek pouch model has a history of successfully identifying chemicals and foods with cancer preventing activity (including BRBs), exploratory and comparative molecular studies are hampered by the lack of hamster genome information and subsequent lack of reagents and tools for in depth systems biology investigations. Therefore, another suitable animal model of oral cancer must be employed. The rat tongue/4NQO system of oral carcinogenesis represents such an established and well-studied model for the investigation of black raspberry-mediated oral chemoprevention. The present proposal will explore the ability of BRBs to inhibit oral cancer using the rat tongue model and compare the molecular efficacy of BRBs in the rat tongue to that which has been established in human oral tumors and "high-at-risk" mucosa. We hypothesize that the bioactive components in BRBs will inhibit tumorigenesis and decrease the expression of clinically relevant, pro-inflammatory molecular biomarkers associated with oral carcinogenesis. The following Specific Aims uniquely combines aspects of nutrition, molecular efficacy, and cancer prevention to address the proposed hypothesis. Studies proposed in Specific Aim 1 will establish the ability of dietary BRBs or a single BRB bioactive component (ellagic acid; EA) to inhibit tongue lesion formation during 4NQO-induced oral carcinogenesis in F344 rats. Studies proposed in Specific Aim 2 will determine the comparative molecular efficacy of BRBs and EA on rat tongue carcinogenesis using a clinically-relevant transcriptional profile of genes previous shown to be modulated by BRBs in tumor and "high at-risk" oral mucosal cells of oral cancer patients. Following the successful completion of the above Specific Aims, our novel studies will (i) define the chemopreventive potential of dietary BRBs in a rat tongue model of oral cancer, (ii) validate a signature of BRB molecular efficacy in rat oral mucosa that is directly relevant to human oral cancer and (iii) provide a foundation for future mechanistic investigation of oral cancer chemoprevention.