NOX4 Mediates Oxidative Stress in Ovarian Tumor growth and treatment Response

 描述（由申请人提供）：卵巢癌是女性癌症相关死亡的第五大原因。然而，卵巢癌发生的机制及其对治疗的反应仍有待阐明。我们的初步结果表明，与永生化的正常卵巢上皮细胞相比，卵巢癌细胞通过 NOX4 过表达产生更高水平的活性氧 (ROS)。癌细胞中 NOX4 的敲低会减少 ROS 的产生以及 HER2、HER3 和 ATG14 的表达。为了测试 NOX4 在卵巢癌细胞中的上调情况，我们发现 HIF-1 和 p70S6K1 在这些细胞中被激活。众所周知，HIF-1 和 p70S6K1 可以被 PI3K 和 Ras 等癌基因以及 PTEN 和 p53 等抑癌基因突变激活。我们的初步结果表明 HIF-1 和 p70S6K1 诱导 NOX4 过度表达。我们假设 HIF-1 和 p70S6K1 诱导 NOX4 过度表达，进而通过抑制 miR-199a/miR-152 诱导 HER2/HER3 共表达和 ATG14 表达，导致卵巢肿瘤生长、血管生成和治疗耐药。我们将使用多学科方法，包括分子生物学、动物模型和人类癌症组织分析，通过三个具体目标来检验我们的假设。目标 1 将确定 HIF-1 和 p70S6K1 是否诱导 NOX4 表达，进而介导 HER2 和 HER3 共表达； NOX4是否通过HER2和HER3调节曲妥珠单抗治疗抵抗，并通过诱导自噬和ATG14表达调节放射治疗抵抗。我们将操纵细胞中 HIF-1、p70S6K1、NOX4 和其他分子的表达，并定义这些分子在曲妥珠单抗和放射治疗反应中的作用。目标 2 将使用原位卵巢肿瘤模型确定 NOX4 是否通过 miR-199a 抑制通过 HER2 和 HER3 共表达诱导卵巢肿瘤生长，并使用图像引导放射治疗确定 NOX4 是否通过 ATG14 影响放射治疗效果。目标3将确定NOX4是否通过抑制HER2、HER3和miR-199a来调节肿瘤血管生成；并研究 NOX4、ROS、HER2、HER3、miR-199a 和 miR-152 的水平是否与晚期卵巢癌分期和生存相关。总而言之，从本申请获得的这些结果将建立 NOX4 信号传导调节卵巢癌发展的新分子机制，并为 NOX4 如何调节放射和曲妥珠单抗治疗耐药性提供原理证明。这些结果将为设计针对卵巢癌治疗的 NOX4、HER2/HER3 共表达和/或 ATG14 的新治疗方法提供基础。这些研究还将提供新的生物标志物，使用更高水平的 NOX4、ROS、ATG14 和/或 HER2/HER3 共表达来预测未来晚期卵巢癌分期、放射或/和曲妥珠单抗治疗耐药性。

 DESCRIPTION (provided by applicant): Ovarian cancer represents the fifth leading cause of cancer-related death among women. However, the mechanisms of ovarian cancer development and its response to treatment remain to be elucidated. Our preliminary results show that ovarian cancer cells generate higher levels of reactive oxygen species (ROS) through NOX4 overexpression compared to immortalized normal ovary epithelial cells. Knockdown of NOX4 in cancer cells decreased ROS production, as well as expression of HER2, HER3 and ATG14. To test how NOX4 is upregulated in ovarian cancer cells, we find that HIF-1 and p70S6K1 are activated in these cells. It is known that HIF-1 and p70S6K1 are activated by oncogenes, such as PI3K and Ras, and by mutations of tumor suppressors, such as PTEN and p53. Our preliminary results indicate that HIF-1 and p70S6K1 induce NOX4 overexpression. We hypothesize that HIF-1 and p70S6K1 induce NOX4 overexpression, which in turn induces HER2/HER3 co-expression and ATG14 expression through miR-199a/miR-152 suppression, leading to ovarian tumor growth, angiogenesis, and therapeutic resistance. We will use multidisciplinary approaches, including molecular biology, animal models and human cancer tissue analysis, to test our hypothesis through three specific aims. Aim 1 will determine whether HIF-1 and p70S6K1 induce NOX4 expression, which in turn mediates HER2 and HER3 co-expression; whether NOX4 regulates trastuzumab treatment resistance through HER2 and HER3, and regulates radiation treatment resistance through induction of autophagy and ATG14 expression. We will manipulate expression of HIF-1, p70S6K1, NOX4 and other molecules in the cells and define the roles of these molecules in trastuzumab and radiation treatment responses. Aim 2 will determine whether NOX4 induces ovarian tumor growth through HER2 and HER3 co-expression via miR-199a suppression using an orthotopic ovarian tumor model, and determine whether NOX4 affects radiation treatment effect via ATG14 using image-guided radiotherapy. Aim 3 will determine whether NOX4 regulates tumor angiogenesis through HER2, HER3, and miR-199a suppression; and investigate whether levels of NOX4, ROS, HER2, HER3, miR-199a, and miR-152 correlate with advanced ovarian cancer stages and survival. Taken together, these results obtained from this application will establish a novel molecular mechanism of NOX4 signaling in regulating ovarian cancer development and provide proof- of-principle as to how NOX4 regulates radiation and trastuzumab treatment resistance. These results will provide the basis for designing a new therapeutic approach by targeting NOX4, HER2/HER3 co-expression, and/or ATG14 for ovarian cancer therapy. These studies will also provide new biomarker(s) using higher levels of NOX4, ROS, ATG14, and/or HER2/HER3 co-expression to predict advanced ovarian cancer stages, radiation or/and trastuzumab treatment resistance in the future.