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.

全腹放射治疗（WART）是治疗胃肠道癌症的主要方法， 已经扩散到腹腔内组织虽然有效，但这种方法是有限的，因为 WART与全剂量化疗方案增加了对正常组织的毒性。最近的研究 证明了在一种新的治疗模式中的生存优势，这种治疗模式允许安全使用全剂量 全身化疗联合低剂量分次放疗（LDFRT）。传统上， 放射治疗使用大于1.20戈伊的剂量，因为人们认为较低的辐射剂量 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）， 在许多增殖的细胞中，细胞在低至0.15戈伊的辐射剂量下经历凋亡的现象。 细胞我们的目标是开展临床前研究，以调查 LDFRT在播散性腹腔内癌中的化学增强作用。我们的数据显示， 连续每日剂量为0.15戈伊可在胃癌细胞中产生HRS，并增强了改良的 多西他赛、顺铂和5 '-氟尿嘧啶（mDCF）方案。集落存活测定表明，0.15戈伊是 当LDFRT与mDCF组合时，足以杀死90%的细胞，而当LDFRT与mDCF组合时，几乎高十倍 当单独使用常规放射治疗时，需要1.35戈伊的剂量来达到相同的率。RT2 PCR 对300多个基因的Profiler阵列分析表明，双氧化酶2（DUOX 2），一种功能酶， 在过氧化氢的产生中，是迄今为止对这种组合的反应中上调最多的基因。 方案，而参与DNA修复的基因显然不参与。此外，下调 DUOX 2在每个辐射剂量下都增加了辐射抗性。此外，我们的数据表明， 在暴露于LDFRT和mDCF的细胞中，氧物质增加高达3.5倍。此外，抑制 NAD（P）H氧化酶消除了这种联合方案的杀伤效率。这些发现特别 重要的是，DUOX 2仅在约50%的胃癌中表达（初步数据）。DUOX2 因此，可以用作生物标志物，以潜在地对晚期和转移性胃癌患者进行分层。 腹腔内癌症的LDFRT化学增强的临床应用。我们的假设是 在胃癌中LDFRT的化学增强作用由DUOX 2介导。为了验证这个假设 制定了三个具体目标。目标1。确定DUOX 2对人胃癌细胞的作用 LDFRT在体内对化学增强作用的反应进展。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DU 0X 2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。另外我们 将确定DUOX 2的激活是否可用作联合方案的生物标志物， 通过测量蛋白质羰基来测量活性氧（ROS）和对蛋白质的氧化损伤 小鼠血清中的水平。目的2：阐明导致DUOX 2上调的分子机制 LDFRT的化学增强作用。重点将放在DUOX 2转录和转录后 调控在目标3中，我们将评估DUOX 2对免疫应答和肿瘤的影响。 微环境。这将在同基因小鼠模型中进行，其中DUOX 2对血管系统有影响， 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DUOX 2为化学增强作用的主要贡献者，并可能重新评估 WART的辐射剂量比传统剂量低十倍，试图减少内部- 腹部复发的疾病。除了提供对分子机制的深入了解外， 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 暴露在电离辐射下