NOX4 mediates oxidative stress in ovarian tumor growth and treatment response

 描述(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，卵巢癌的发生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的过度表达产生更高水平的活性氧(ROS)。在癌细胞中敲除NOX4会减少ROS的产生，以及HER2、HER3和ATG14的表达。为了测试NOX4在卵巢癌细胞中是如何上调的，我们发现HIF-1和p70S6K1在这些细胞中被激活。已知HIF-1和p70S6K1由癌基因如PI3K和RAS以及肿瘤抑制基因突变如PTEN和P53激活。我们的初步结果表明，HIF-1和p70S6K1诱导NOX4过表达。我们假设HIF-1和p70S6K1诱导NOX4过表达，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。目的1确定HIF-1和p70S6K1是否诱导NOX4的表达，进而介导HER2和HER3的共同表达；NOX4是否通过HER2和HER3调节曲妥珠单抗的耐药性，以及是否通过诱导自噬和ATG14的表达来调节放射治疗的耐药性。我们将操纵HIF-1、p70S6K1、NOX4和其他分子在细胞中的表达，并确定这些分子在曲妥珠单抗和放射治疗反应中的作用。目的2利用原位卵巢肿瘤模型，确定NOX4是否通过抑制miR-199a而通过HER2和HER3共表达而诱导卵巢肿瘤生长，以及图像引导下NOX4是否通过ATG14影响放射治疗效果。目的3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水平是否与晚期卵巢癌分期和生存期相关。综上所述，从这一应用中获得的这些结果将建立一个新的NOX4信号在调控卵巢癌发展中的分子机制，并为NOX4如何调节辐射和曲妥珠单抗治疗耐药性提供原理证据。这些结果将为设计针对NOX4、HER2/HER3共表达和/或ATG14治疗卵巢癌的新的治疗方法提供基础。这些研究还将提供新的生物标志物(S)，使用更高水平的NOX4、ROS、ATG14和/或HER2/HER3共同表达来预测晚期卵巢癌分期、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.