Long term radiation effects in A549 cells - PML knock down and carbon ion vs. photon irradiation
Ontology highlight
ABSTRACT: The aim of our study is to investigate the effects of carbon ion and photon irradiation on A549 tumor cells and analyse how these effects are altered by PML knockdown. Therefore we created PML knockdown A549 cells (shPML) and irradiated them with either 2Gy carbon ion or 6Gy Photon (bioequivalent doses). 4 days after irradiation microarray analysis was performed. All experiments were performed in 3 biological replicates and control groups were transduced with an empty vector.
Project description:The aim of our study is to investigate and compare the effects of carbon and photon irradiation on microvascular endothelial cells. Therefore we irradiated human pulmonary microvascular endothelial cells (HPMEC) with either 2Gy Carbon or 6Gy Photon (bioequivalent doses) and performed microarray analysis both 2 hours (short-term effect) and 6 days (long-term effects) after irradiation. All experiments were performed in 3 biological replicates.
Project description:Carbon-ion irradiation is an emerging therapeutic option for several tumor entities including lung cancer. Well oxygenated tumor areas compared to a hypoxic environment favor therapeutic photon irradiation efficiency of solid tumors due to increased amounts of DNA damage. The resistance of hypoxic tumor areas towards photon irradiation is enhanced through increased HIF-1 signaling. Here, we compared the effects of oxygen and HIF 1 after photon and carbon-ion irradiation with biological equivalent doses in a human non-small lung cancer model. In hypoxia compared to normoxia, A549 and H1299 cells displayed improved survival after photon irradiation. Knockdown of HIF-1M-NM-1 combined with photon irradiation synergistically delayed tumor growth in vivo. Photon irradiation induced HIF-1M-NM-1 and several of its target genes such as PDK1, GLUT-1, LDHA, and VEGF with subsequent enhanced tumor angiogenesis in vivo, a signaling cascade that was not targeted by carbon-ion irradiation. We present evidence that photons but not carbon-ions induce HIF-1M-NM-1 via mTOR pathway. Importantly, after carbon-ion irradiation in vivo, we observed substantial downregulation of HIF-1M-NM-1 and a drastically delayed tumor growth indicating a considerable higher relative biological effectiveness (RBE) than anticipated from the cell survival data. In sum, our results demonstrate that carbon-ions mediate an improved therapeutic response of tumor treatment compared to photon irradiation that is independent of cell oxygenation and HIF-1 signaling. 16 independent cell cultures were used. Each culture was split into an irradiated and a control plate, yieldin a total of 16 paired samples. Paired samples were analysed in 16 two-color hybridizations. Factors time (after irradiation) with levels 1h and 4h and factor radiation quality with levels C12 and X-rays were analyzed. Each of the 2x2 combinations was analyzed in 4 independent experiments.
Project description:Endostatin is a naturally occurring 183-amino acid proteolytic fragment of collagen XVIII that localizes in the basement membrane around blood vessels. The anti-tumor properties of this protein have been extensively described, demarcating endostatin as an endogenous inhibitor of angiogenesis. Further, it supresses many signaling cascades such as pro-inflammatory NF-κB, coagulation and adhesion cascades. Yamaguchi et al. reported that endostatin via its C-terminal domain (E4 peptide) has elicit anti-fibrosis effects. However, the zinc binding domain has been previously confined to the N terminus (endostatin mP1 peptide) and was critical to numerous functions of the molecule. The present study aimed to better understand the impact of oligomerization (Fc-Endostatin) as well as N- vs. C-terminal fragments of endostatin (mP1, CE4) on modulating radiation-induced lung fibrosis. Mice were treated with Fc-endostatin (Fc-Endo), N-terminus endostatin peptide (mP1) or C-terminus endostatin E4 peptide (CE4) combined with photon 20 Gy or carbon-ions 12.5 Gy whole thoracic irradiation
Project description:The potential mechanisms of DNA-PKcs and its related signaling pathways in radiation-induced pulmonary toxicity is unclear. The current study utilized genetic engineering DNA-PKcs knockout mouse model, to investigate the molecular mechanisms after dose-response exposure of of the fractionated low-LET photon and high-LET carbon-ion exposure to the whole thorax.
Project description:Normal lung tissue tolerance constitutes a limiting factor in delivering the required dose of radiotherapy to cure thoracic and chest wall malignancies. Patient genetic predisposition, the volume of irradiated lung and combination regimens consisting of concurrent chemotherapy are correlated with increased risk of radiation induced toxicity in lung. The main purpose of this study is to investigate dose-response regulations of mouse lung irradiation based on a comprehensive dose-escalation program, for a better understanding of molecular mechanism governing radiation induced lung fibrosis by high-LET carbon-ions versus conventional low-LET X-ray.
Project description:The time factor in the development of radiation induced lung fibrosis is important but not well characterized so far. This study was to investigate the time series of acute-, subacute-, early and late- timepoints after exposure with low-LET photons versus proton versus and high-LET carbon-ions. The role of CTGF inhibitor in modulating inflammation related signaling pathways were also studied at the acute timepoints. The potential mechanisms underlining the time-dependent progression of inflammatory and fibrotic response is to be illustrated in the present study.
Project description:Subcutaneous A431 tumors in the right hind limb of NCr nu/nu mice were treated with 5 daily fractions of external beam radiotherapy (2 Gy photon or 1 Gy carbon per fraction), a single fraction of 7.2 MBq 131Iodine-labelled Cetuximab intravenously or a combination of the two. Untreated tumors served as controls. Mice were sacrificed and tumor tissue collected for expression profiling 5 days after endoradiotherapy of 1 week after the last fraction of external beam radiotherapy.
Project description:Subcutaneous B16F10 tumors in the right hind limb of C57BL/6 mice were treated with 5 daily fractions of external beam radiotherapy (8 Gy photon or 5 Gy carbon per fraction), a single fraction of 13.3 MBq 131Iodine-labelled benzamide-derivative MIP-1145 intravenously or a combination of the two. Untreated tumors served as controls. Mice were sacrificed and tumor tissue collected for expression profiling 5 days after endoradiotherapy of 1 week after the last fraction of external beam radiotherapy.
Project description:In recent years there is a growing epidemiological indication of excess risk of cardiovascular disease at low doses of ionizing radiation without a clear-cut threshold. It is proposed that damage to the vascular endothelium is critical in radiation-related cardiovascular diseases. In order to identify and better understand the underlying molecular mechanisms of high LET (Fe ions) and low LET (X-ray) radiation on endothelial cells, we performed a microarray analysis on immortalized human coronary artery endothelial cells irradiated with 2.00 Gy and compared them with sham-irradiated samples. RNA was extracted at different time points after irradiation (1 day, 7 days).
Project description:In the present study approximately 1 to 2 mm3 prostate tumor AT1 was inoculated subcutaneously in the right hind leg of adult male Copenhagen rats. When the tumor diameter exceeded 15 mm, tumors of 5 and 4 rats were irradiated with carbon ion radiation of 37 or 16Gy respectively. Tumors of 5 other rats were irradiated with photon radiation of 37Gy. One animal irradiated with 37 Gy carbon ion radiation and one animal irradiated with photon radiation was sacrificed 12h, 30h, 72h, 7d and 14d after irradiation respectively. One animal irradiated with 16 Gy photon radiation was sacrificed 12h, 60h, 7d and 14d after irradiation respectively. Non-irradiated animals were sacrificed at 60h time point. Tumors were dissected and frozen in liquid nitrogen immediately. Total RNA from tumor material was isolated using the NucleoSpin RNA L kit (#740962.20, Macherey-Nagel). Differential gene expression analysis was performed on the Agilent whole rat genome Oligo Microarray (44k) platform by comparative two dye hybridisation with dye-swaps.