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: 9349730
• 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 2021-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9349730
• 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; Clinical stratification; Collaborations; Combined Modality Therapy; DNA Repair; Data; Disease; Dose; Down-Regulation; Enzymes; Exposure to; Fluorescence; Fluorouracil; Fractionated radiotherapy; Fukushima; Gastric Adenocarcinoma; Genes; Genetic Transcription; Human; Hydrogen Peroxide; Hypoxia; Immune; Immune response; Immunocompetent; Immunologist; Infiltration; Injectable; Injection of therapeutic agent; 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; Radiation Tolerance; Radiation therapy; Radioresistance; Reactive Oxygen Species; Rectal Cancer; Recurrence; Regimen; Regulatory T-Lymphocyte; Research; Role; Serum; Stem cells; Stomach; Stomach Carcinoma; Testing; Therapeutic; Time; Tissues; Toxic effect; Up-Regulation; Work; Xenograft Model; Xenograft procedure; cancer cell; cancer therapy; chemotherapy; clinical application; density; docetaxel; in vivo; insight; killings; macrophage; malignant stomach neoplasm; mouse model; novel; optical imager; oxidative damage; patient stratification; preclinical study; programs; radiosensitive; response; 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.

全腹放射治疗是治疗胃肠道肿瘤的主要方法。 已经扩散到腹内组织。虽然这种方法很有效，但它是有限的，因为 采用全剂量化疗方案的疣会增加对正常组织的毒性。最近的研究表明 在一种允许安全使用全剂量的新治疗范例中展示了生存优势 全身化疗联合低剂量分割放射治疗(LDFRT)。传统上， 放射治疗使用大于1.20GY的剂量，因为人们认为较低的辐射剂量将是 对肿瘤治疗无效。我们现在知道LDFRT可以产生超辐射敏感性(HRS)，一种 一种现象，即细胞在低至0.15Gy射线的辐射剂量下发生凋亡，在许多增殖中 细胞。我们的目标是开发临床前研究，以调查治疗潜力 LDFRT化疗增强治疗播散性腹内癌。我们的数据显示，有三个 连续每天0.15Gy射线照射可在胃癌细胞中产生HRS，并增强一种改良的 多西紫杉醇、顺铂和5‘-氟尿嘧啶(MDCF)方案。集落存活实验表明，0.15Gy. 当LDFRT与MDCF相结合时，足以杀死90%的细胞，而几乎高出十倍 单纯使用常规放射治疗需要1.35Gy才能达到同样的疗效。RT2聚合酶链式反应 对300多个基因的分析表明，双氧合酶2(DUOX2)是一种发挥作用的酶 在产生过氧化氢的过程中，是迄今为止对此反应最上调的基因组合 而参与DNA修复的基因显然没有参与其中。此外，下调对 DUOX2在所测试的每个辐射剂量下都增加了辐射抗性。此外，我们的数据表明，反应性 暴露在LDFRT和MDCF中的细胞中的氧物种增加了3.5倍。此外，抑制 NAD(P)H氧化酶取消了这种联合方案的杀灭效率。这些发现尤其是 重要的是，DUOX2只在大约50%的胃癌中表达(初步数据)。DUOX2 因此可以作为一个潜在的生物标志物来对进展期和转移性胃癌患者进行分层。 激光立体定向放射治疗腹内癌的临床应用。我们的工作假设是 在胃癌中，LDFRT的化学增强是由DUOX2介导的。为了检验这一假说 已经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对化学增强反应的研究进展。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低水平的DUOX2和荧光标记物。 治疗后将使用Xenogen IVIS光学成像仪监测癌症进展。此外，我们 将通过以下方式确定DUOX2的激活是否可以用作联合方案的生物标志物 通过测定蛋白质的羰基来测定蛋白质的活性氧簇(ROS)和氧化损伤 小鼠血清中的水平。目的2：阐明DUOX2表达上调的分子机制 对LDFRT的化学增强作用。重点将放在DUOX2转录和转录后 监管。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对血管系统产生影响， 将对缺氧、免疫细胞渗透和干细胞进行监测。这项提议的独特之处在于 LDFRT鉴定DUOX2是化学潜势的主要贡献者及其重新审视的可能性 用比常规剂量低十倍的辐射剂量治疗疣，试图减少体内的 腹部复发的疾病。除了提供对分子机制的洞察之外 在对低剂量辐射的潜在治疗反应中，这些研究也可以用来确定标志物 暴露在电离辐射中。