Chemopotentiation by Low Dose Fractionated Radiation Therapy for disseminated intra-abdominal cancers

低剂量分割放射治疗播散性腹腔内癌症的化学增强作用

• 批准号: 10327267
• 负责人: France Carrier
• 金额: --
• 依托单位: BALTIMORE VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10327267
• 关键词: Abdomen; Afghanistan; Apoptosis; Attention; Biological Assay; Biological Markers; C57BL/6 Mouse; CD8-Positive T-Lymphocytes; Cancer Patient; Carcinogens; Carcinomatosis; Cells; Chemotherapy-Oncologic Procedure; Cisplatin; Collaborations; Combined Modality Therapy; DNA Repair; Data; Disease; Dose; Down-Regulation; Enzymes; Exposure to; Fluorescence; Fluorouracil; Fractionated radiotherapy; Fukushima; Gastric Adenocarcinoma; Genes; Human; Hydrogen Peroxide; Hypoxia; Immune; Immune response; Immunocompetent; Immunologist; Infiltration; Injections; Intra-abdominal; Ionizing radiation; Iraq; Japan; Knowledge; Low Dose Radiation; Malignant neoplasm of abdomen; Malignant neoplasm of gastrointestinal tract; Measures; Mediating; Methods; Modeling; Molecular; Monitor; Morphology; Mus; Normal tissue morphology; Nuclear Accidents; Nude Mice; Oxidases; Pathologist; Patients; Perfusion; Peritoneal; Post-Transcriptional Regulation; Production; Proliferating; Proteins; Radiation Dose Unit; Radiation Tolerance; Radiation therapy; Reactive Oxygen Species; Rectal Cancer; Recurrence; Regimen; Regulatory T-Lymphocyte; Research; Role; Serum; Stomach; Stomach Carcinoma; Testing; Therapeutic; Time; Tissues; Toxic effect; Transcriptional Regulation; Up-Regulation; Work; Xenograft Model; Xenograft procedure; burn pit; cancer therapy; chemotherapy; clinical application; density; docetaxel; fractionated radiation; gastric cancer cell; in vivo; insight; macrophage; malignant stomach neoplasm; mouse model; novel; optical imager; oxidative damage; patient stratification; preclinical study; programs; radiation resistance; response; stem cells; treatment response; tumor; tumor microenvironment; tumor progression

Whole abdominal radiotherapy (WART) is a primary method for managing gastrointestinal cancers that have disseminated into intra-abdominal tissues. While effective, this approach is limited since combination of WART with full-dose chemotherapy regimens increase toxicity to normal tissue. Recent studies have demonstrated a survival advantage in a novel treatment paradigm that allows for the safe use of full-dose systemic chemotherapy in combination with Low Dose Fractionated Radiotherapy (LDFRT). Traditionally, radiotherapy used doses greater than 1.20 Gy because it was thought that lower radiation doses would be ineffective for tumor therapy. We now know that LDFRT can produce hyper-radiosensitivity (HRS), a phenomenon where cells undergo apoptosis at radiation doses as low as 0.15 Gy, in a number of proliferating cells. Our objectives are to develop pre-clinical studies to investigate the therapeutic potential of chemopotentiation by LDFRT in disseminated intra-abdominal cancer. Our data indicate that three consecutive daily fractions of 0.15 Gy produced HRS in gastric cancer cells and potentiated a modified regimen of Docetaxel, Cisplatin, and 5’-fluorouracil (mDCF). Colony survival assays indicated that 0.15 Gy was sufficient to kill 90% of the cells when LDFRT was combined with mDCF whereas an almost ten times higher dose (1.35 Gy) was needed to achieve the same rate when using conventional radiotherapy alone. RT2 PCR Profiler Array analysis of more than 300 genes indicated that Dual Oxidase 2 (DUOX2), an enzyme functioning in the production of hydrogen peroxide, was by far the most upregulated gene in response to this combined regimen while genes involved in DNA repair were apparently not involved. Moreover, down regulation of DUOX2 increased radioresistance at every radiation doses tested. In addition, our data indicate that Reactive Oxygen Species increase up to 3.5 fold in cells exposed to LDFRT and mDCF. Furthermore, inhibition of NAD(P)H oxidase abrogated the killing efficiency of this combined regimen. These findings are particularly important given that DUOX2 is only expressed in about 50% of gastric carcinoma (preliminary data). DUOX2 could thus be used as a biomarker to potentially stratify gastric cancer patients with advanced and metastatic intra-abdominal cancers for clinical applications of chemopotentiation by LDFRT. Our working hypothesis is that Chemopotentiation by LDFRT is mediated by DUOX2 in gastric cancers. In order to test this hypothesis three Specific aims have been developed. Aim 1. Determine the role of DUOX2 on human gastric cancer cells progression in response to chemopotentiation by LDFRT in vivo. We will use human gastric cancer cells expressing endogenous and reduced levels of DUOX2 and a fluorescence marker in mouse xenograft models. Cancer progression will be monitored with a Xenogen IVIS optical imager following treatments. In addition, we will determine whether activation of DUOX2 can be used as a biomarker for the combined regimen by measuring Reactive Oxygen Species (ROS) and oxidative damage to proteins by measuring protein carbonyl levels in mice serum. Aim 2: Delineate the molecular mechanisms leading to DUOX2 upregulation in response to chemopotentiation by LDFRT. Emphasis will be on DUOX2 transcriptional and post-transcriptional regulation. In Aim 3, we will evaluate the effect of DUOX2 on the immune response and the tumor microenvironment. This will be performed in a syngeneic mouse model where DUOX2 effect on vasculature, hypoxia, immune cells infiltration, and stem cells will be monitored. The unique aspect of this proposal is the identification of DUOX2 as a major contributor to chemopotentiatoin by LDFRT and the possibility to revisit WART with radiation doses ten times lower than the conventional dose in an attempt to decrease intra- abdominal recurrence of the disease. In addition to providing insight into the molecular mechanisms underlying therapeutic responses to low dose radiation, these studies could also be used to identify markers for exposure to ionizing radiation.

全腹部放疗（WART）是治疗胃肠道癌症的主要方法， 已播散至腹腔内组织。虽然有效，但这种方法是有限的，因为结合 WART 与全剂量化疗方案会增加对正常组织的毒性。最近的研究有 在允许安全使用全剂量的新型治疗范例中证明了生存优势 全身化疗联合低剂量分割放射治疗（LDFRT）。传统上， 放射治疗使用的剂量大于 1.20 Gy，因为人们认为较低的放射剂量会 对肿瘤治疗无效。我们现在知道 LDFRT 可以产生超放射敏感性 (HRS)，这是一种 细胞在低至 0.15 Gy 的辐射剂量下发生凋亡的现象，在许多增殖细胞中 细胞。我们的目标是开展临床前研究以调查其治疗潜力 LDFRT 在播散性腹腔内癌症中的化学增强作用。我们的数据表明，三 连续每日 0.15 Gy 的剂量在胃癌细胞中产生 HRS，并增强了改良的 多西紫杉醇、顺铂和 5’-氟尿嘧啶 (mDCF) 方案。集落存活测定表明 0.15 Gy 当 LDFRT 与 mDCF 结合时，足以杀死 90% 的细胞，而几乎高出十倍 单独使用常规放疗时需要剂量（1.35 Gy）才能达到相同的速率。逆转录聚合酶链反应 Profiler Array 对 300 多个基因的分析表明，双氧化酶 2 (DUOX2) 是一种具有功能的酶 在过氧化氢的产生中，是迄今为止对这种组合反应上调最多的基因 方案，而涉及 DNA 修复的基因显然没有参与。此外，下调 DUOX2 在每次测试的辐射剂量下都会增加辐射抗性。此外，我们的数据表明，Reactive 暴露于 LDFRT 和 mDCF 的细胞中的氧种类增加高达 3.5 倍。此外，抑制 NAD(P)H 氧化酶消除了该联合方案的杀灭效率。这些发现特别 鉴于 DUOX2 仅在约 50% 的胃癌中表达（初步数据），这一点很重要。双氧酶2 因此可以用作生物标志物，对晚期和转移性胃癌患者进行潜在分层 腹内癌 LDFRT 化学增强的临床应用。我们的工作假设是 在胃癌中，LDFRT 的化学增强作用是由 DUOX2 介导的。为了检验这个假设 制定了三个具体目标。目的1.确定DUOX2对人胃癌细胞的作用 体内 LDFRT 化学增强反应的进展。我们将使用人类胃癌细胞 在小鼠异种移植模型中表达内源性和降低水平的 DUOX2 和荧光标记。 治疗后将使用 Xenogen IVIS 光学成像仪监测癌症进展。此外，我们 将确定 DUOX2 的激活是否可以用作联合治疗方案的生物标志物 通过测量蛋白质羰基来测量活性氧 (ROS) 和蛋白质的氧化损伤 小鼠血清中的水平。目标 2：描述导致 DUOX2 响应上调的分子机制 通过 LDFRT 进行化学增效。重点将放在 DUOX2 转录和转录后 规定。在目标3中，我们将评估DUOX2对免疫反应和肿瘤的影响 微环境。这将在同基因小鼠模型中进行，其中 DUOX2 对脉管系统产生影响， 将监测缺氧、免疫细胞浸润和干细胞。该提案的独特之处在于 通过 LDFRT 鉴定 DUOX2 作为化学增效的主要贡献者以及重新审视的可能性 WART 的辐射剂量比常规剂量低十倍，试图减少体内 腹部疾病复发。除了提供对分子机制的见解 对低剂量辐射的潜在治疗反应，这些研究也可用于识别标记物 用于暴露于电离辐射。