PURPOSE: The purpose of this study was to identify Radiosensitivity of proteins in tissues with different radiosensitivity. MATERIALS AND METHODS: C3H/HeJ mice were exposed to 10 Gy. The mice were sacrifiud 8 hrs after radiation. Their spleen and liver tissues were collected and analyzed histologicaly for apoptosis. The expressions of radiosusceptibility protein were analyzed by 2-dimensional electrophoresis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. RESULTS: The peak of apoptosis levels were 35.3+/-1.7% in spleen and 0.6+/-0.2% in liver at 8 hrs after radiation. Liver, radioresistant tissues, showed that the levels of ROS metabolism related to proteins such as cytochromm c, glutathione S transferase, NADH dehydrogenase, riken cDNA and peroxiredoxin VI increased after radiation. The expression of cytochrome c increased significantly in spleen and liver tissues after radiation. In spleen, radiosensitivity tissue, the identified proteins showed a significantly quantitative alteration following radiation. It was categorized as signal transduction, apoptosis, cytokine, Ca signal related protein, stress-related protein, cytoskeletal regulation, ROS metabolism, and others. CONCLUSION: Differences of radiation-induced apoptosis by tissues specifted were coupled with the induction of related radiosensitivity and radioresistant proteins. The result suggests that apoptosis relate protein and redox proteins play important roles in this radiosusceptibility.
Animals ; Apoptosis ; Cytochromes c ; DNA, Complementary ; Electrophoresis ; Glutathione Transferase ; Liver ; Mass Spectrometry ; Metabolism ; Mice ; NADH Dehydrogenase ; Oxidation-Reduction ; Peroxiredoxin VI ; Proteomics* ; Radiation Tolerance* ; Signal Transduction ; Spleen

In understanding radiosensitivity a new concept of inherent radiosensitivity based on individuality and heterogeneity within a population has recently beer explored. There has been some discussion of possible mechanism underlying differences in radiosensitivity between cells. Ataxia telangiectasia(AT), a rare autosomal recessive genetic disorder, is characterized by hypersensitivity to lonizing radiation and other DNA damaging agents at the cellular level. There have been a lot of efforts to describe the cause of this hypersensitivity to radiation. At the cellular level, chromosome repair kinetics study would be an appropriate approach. The purpose of this study was to better understand radiosensitivity in an approach to investigate kinetics of induction and repair of G2 chromatic breaks using normal, AT heterozygous(ATH), and AT homozygous lymphoblastoid cell lines. In an attempt to estimate initial damage, 9-betaD-arabinosyl-2-fluoroadenine, an inhibitor of DNA synthesis and repair, was used in this study. It was found from this study that radiation induces higher chromatid breaks in AT than in normal and ATH cells. There was no significant differences of initial chromatid breaks between normal and ATH cells. Repair kinetics was the same for all. So the higher level of breaks in AT G2 cells is thought to be a reflection of the increased initial damage. The amount of initial damage correlated well with survival fraction at 2 Gy of cell survival curve following radiation. Therefore, the difference of radiosensitivity in terms of G2 chromosomal sensitivity is thought to result from the difference of initial damage.
Ataxia ; Beer ; Cell Line ; Cell Survival ; Chromatids ; DNA ; Humans* ; Hypersensitivity ; Individuality ; Kinetics* ; Population Characteristics ; Radiation Tolerance

PURPOSE: To characterize strain-specific differences in radiation response in murine tissues with different radiosensitivity. MATERIALS AND METHODS: Six-week old male mice of 2 strains, C57Bl/6J and C3H/HeJ, were given whole body gamma-radiation with a single dose of 10 or 25 Gy. At different times after irradiation, mice were killed and tissues with different radiosensitivity, thymus and liver, were collected. Each tissue sample was stained with hematoxylin and eosin and apoptotic cells were scored. Expression of p53, Bcl-2, Bcl-x, and Bax was analysed by western blotting and densitometry. RESULTS: Radiation induced massive apoptosis in thymus with a peak level at 8 h after radiation. With 10 Gy irradiation, apoptotic indices in C57Bl/6J and C3H/HeJ were 81.0 2.5% and 59.4 4.0%, respectively (p<0.05). Radiation upregulated the expression of p53, Bcl-x, and Bax, but not Bcl-2; p53 with a peak level of 2.5 fold (C57Bl/6J) and 1.4 fold (C3H/HeJ) at 4 h, Bax with a peak level of 2.6 fold (C57Bl/6J) and 1.3 fold (C3H/HeJ) at 8 h, and Bcl-x with a peak level of 11.1 fold (C57Bl/6J) and 8.2 fold (C3H/HeJ) at 8 h after radiation. In liver, however, radiation-induced apoptosis was minimal (peak apoptotic index of 2.1% in C57Bl/6J and 1.7% in C3H/HeJ). None of p53, Bcl-2, Bcl-x, and Bax was significantly increased. CONCLUSIONS: Induction of apoptosis and regulation of related genes by radiation were tissue specific. Strain difference of radiation-induced apoptosis was well coupled with theinduction of related genes in thymus, a radiosensitive tissue. This study shows that quantitative difference of radiation induced apoptosis by strain is regulated at the gene level with the involvement of multiple genes.
Animals ; Apoptosis* ; Blotting, Western ; Densitometry ; Eosine Yellowish-(YS) ; Hematoxylin ; Humans ; Liver ; Male ; Mice ; Radiation Tolerance ; Thymus Gland

No abstract available.
Apoptosis* ; Fas Ligand Protein

PURPOSE: Extracellular signal-regulated kinase (ERK), which is part of the mitogen-activated protin kinase cascade, opposes initiation of the apoptotic cell death which is programmed by diverse cytotoxic stimuli. In this regard, the inhibition of ERK may be useful in improving the therapeutic efficacy of established anticancer agents. MATERIALS AND METHODS: Murine hepatocarcinoma, HCa-I is known to be highly radioresistant with a TCD50 (radiation dose yield in 50% cure) of more than 80 Gy. Various anticancer drugs have been found to enhance the radioresponse of this particular tumor but none were successful. The objective of this study was to explore whether the selective inhibition of MEK could potentiate the antitumor efficacy of radiation in vivo, particularly in the case of radioresistant tumor. C3H/HeJ mice bearing 7.5~8 mm HCa-I, were treated with PD98059 (intratumoral injection of 0.16 microgram in 50 microliter). RESULTS: Downregulation of ERK by PD98059 was most prominent 1h after the treatment. In the tumor growth delay assay, the drug was found to increase the effect of the tumor radioresponse with an enhancement factor (EF) of 1.6 and 1.87. Combined treatment of 25 Gy radiation with PD98059 significantly increased radiation induced apoptosis. The peak apoptotic index (number of apoptotic nuclei in 1000 nuclei X100) was 1.2% in the case of radiation treatment alone, 0.9% in the case of drug treatment alone and 4.9%, 5.3% in the combination treatment group. An analysis of apoptosis regulating molecules with Western blotting showed upregulation of p53, p21WAF1/CIP1 and Bcl-XS in the combination treatment group as compared to their levels in either the radiation alone or drug alone treatment groups. The level of other molecules such as Bcl-XL, Bax and Bcl-2 were changed to a lesser extent. CONCLUSION: The selective inhibition of MEK in combination with radiation therapy may have potential benefit in cancer treatment.
Animals ; Antineoplastic Agents ; Apoptosis ; Blotting, Western ; Cell Death ; Down-Regulation ; Mice ; Phosphotransferases ; Radiation Dosage ; Radiation, Ionizing ; Up-Regulation

With the accumulation of clinical experiences, the efficacy of radiotherapy has been recognized in management scheme for HCC. While hepatologists are beginning to show less reluctance for applying radiotherapy to the treatment of HCC, it is necessary that the hepatologists be informed of the rapid developments in technical strategy for radiation oncology. Recent advances in several technologies have opened a new era in radiation oncology. Modern imaging technologies can provide a 3-dimensional model of patient's anatomy, and this allows radiation oncologists to identify accurate tumor volumes as well as the tumors' relationship with the adjacent normal tissues. Moreover, the development of the computer-controlled multileaf collimator systems now enables physicians to perform precise beam shaping and to modulate the radiation dose distribution. A combination of these systems, 3-DCRT, is rapidly replacing the more conventional 2-D radiotherapy. 3-DCRT has evolved into a more sophisticated technology, intensity modulated radiotherapy (IMRT). In IMRT, with the powerful computer-aided optimization process, the radiation dose can be delivered to the target using highly complex isodose profiles. This new technology has been further developed into IGRT, which combines the CT-images scanning system and radiation equipments into one hardware package, and this system is currently ready for clinical application. In parallel with the radiation technologies described above, the strategy of stereotactic radiation has evolved from the conventional linear accelerator-based system to a gammaknife, and more recently, to a cyberknife. These systems are primarily based on the concept of radiosurgery. Currently, various radiation technologies have been adopted for the radiotherapy of HCC. In this article, each strategy will be discussed as well as the indications for radiotherapy and the radiation-related complications.
Carcinoma, Hepatocellular/*radiotherapy ; English Abstract ; Humans ; Liver Neoplasms/*radiotherapy ; Radiotherapy, Intensity-Modulated

PURPOSE: To compare photon thunderbird with deep match (technique 1) with 3-field technique with electron inguinal boost (technique 2) in acute skin toxicity, toxicity-related treatment breaks and patterns of failure in elective inguinal radiation therapy (RT) for curative chemoradiation in anal cancer. MATERIALS AND METHODS: Seventeen patients treated between January 2008 and September 2010 without evidence of inguinal and distant metastasis were retrospectively reviewed. In 9 patients with technique 1, dose to inguinal and whole pelvis area was 41.4 to 45 Gy and total dose was 59.4 Gy. In 8 patients with technique 2, doses to inguinal, whole pelvis, gross tumor were 36 to 41.4 Gy, 36 to 41.4 Gy, and 45 to 54 Gy, respectively. The median follow-up period was 27.6 and 14.8 months in group technique 1 and 2, respectively. RESULTS: The incidences of grade 3 radiation dermatitis were 56% (5 patients) and 50% (4 patients), dose ranges grade 3 dermatitis appeared were 41.4 to 50.4 Gy and 45 to 54 Gy in group technique 1 and 2, respectively (p = 0.819). The areas affected by grade 3 dermatitis in 2 groups were as follow: perianal and perineal areas in 40% and 25%, perianal and inguinal areas in 0% and 50%, and perianal area only in 60% and 25%, respectively (p = 0.196). No inguinal failure has been observed. CONCLUSION: Photon thunderbird with deep match technique and 3-field technique with electron inguinal boost showed similar incidence of radiation dermatitis. However, photon thunderbird with deep match seems to increase the possibility of severe perineal dermatitis.
Anus Neoplasms ; Chemoradiotherapy ; Dermatitis ; Electrons ; Follow-Up Studies ; Humans ; Incidence ; Neoplasm Metastasis ; Pelvis ; Retrospective Studies ; Skin

PURPOSE: This study evaluated the treatment effectiveness and proper radiation dose of helical tomotherapy (HT) in spine oligometastases from gastrointestinal cancers. MATERIALS AND METHODS: From 2006 to 2010, 20 gastrointestinal cancer patients were treated with HT for spine oligometastases (31 spine lesions). The gross tumor volume (GTV) was the tumor evident from magnetic resonance imaging images fused with simulation computed tomography images. Clinical target volume (CTV) encompassed involved vertebral bodies or dorsal elements. We assumed that the planning target volume was equal to the CTV. We assessed local control rate after HT for 31 spine metastases. Pain response was scored by using a numeric pain intensity scale (NPIS, from 0 to 10). RESULTS: Spine metastatic lesions were treated with median dose of 40 Gy (range, 24 to 51 Gy) and median 5 Gy per fraction (range, 2.5 to 8 Gy) to GTV with median 8 fractions (range, 3 to 20 fraction). Median biologically equivalent dose (BED, alpha/beta = 10 Gy) was 52 Gy10 (range, 37.5 to 76.8 Gy10) to GTV. Six month local control rate for spine metastasis was 90.3%. Overall infield failure rate was 15% and outfield failure rate was 75%. Most patients showed pain relief after HT (93.8%). Median local recurrence free survival was 3 months. BED over 57 Gy10 and oligometastases were identified as prognostic factors associated with improved local progression free survival (p = 0.012, p = 0.041). CONCLUSION: HT was capable of delivering higher BED to metastatic lesions in close proximity of the spinal cord. Spine metastases from gastrointestinal tumors were sensitive to high dose radiation, and BED (alpha/beta = 10 Gy) higher than 57 Gy10 could improve local control.
Disease-Free Survival ; Gastrointestinal Neoplasms ; Humans ; Magnetic Resonance Imaging ; Neoplasm Metastasis ; Radiotherapy, Intensity-Modulated ; Recurrence ; Spinal Cord ; Spine ; Treatment Outcome ; Tumor Burden

PURPOSE: To analyze the involvement of apoptosis regulatory genes p53, p21waf1/cip1, bax and bcl-2 in induction of apoptosis by radiation in murine tumors. MATERIALS AND METHODS: The radiation-sensitive ovarian carcinoma OCa-I, and the radiation-resistant hepatocarcinoma HCa-I were used. Tumors, 8 mm in diameter, were irradiated with 25 Gy and at various times after irradiation, ranging from 1 to 48 h, were analyzed histologically for apoptosis and by western blot for alterations in the expression of these genes. The p53 status of the tumors were determined by the polymerase chain reaction-single strand conformation polymorphism assay. RESULTS: Both tumors were positive for wild-type p53. Radiation induced apoptosis in OCa-I but not in HCa-I. Apoptosis developed rapidly, peaked at 2 h after irradiation and returned to almost the background level at 48 h. In OCa-I radiation upregulated the expression of p53, p21waf1/cip1, and the bcl-2/bax ratio was decreased. In HCa-I radiation increased the expression of both p53 and p21waf1/cip1, although the increase of the latter was small. The bcl-2/bax ratio was greatly increased. In general the observed changes occurred within a few hours after irradiation, and either preceded or coincided with development of apoptosis. CONCLUSIONS: The development of apoptosis required upregulation of both p53 and p21waf1/cip1 as well as a decrease in bcl-2/bax ratio. In contrast, an increase in bcl-2/bax ratio prevented apoptosis in the presence of upregulated p53 and p21waf1/cip1. These findings indentified the involvement of multiple oncogenes in apoptosis regulation in vivo and demonstrate the complexity that may be associated with the use of a single oncogene assessment for predicting the outcome of cancer therapy with cytotoxic agents.
Apoptosis* ; Blotting, Western ; Cytotoxins ; Genes, Regulator ; Oncogenes ; Up-Regulation

PURPOSE: It has been recognized that interaction of the Fas : Fas ligand plays an important role in radiation-induced apoptosis. The purpose of this study was to investigate the role of Fas mutation in radiation-induced apoptosis in vivo. MATERIALS AND METHODS: Mice with mutations in Fas, MRL/Mpj-Fas(lpr), and its normal control, MRL/Mpj, were used in this study. Eight-week old male mice were given whole body radiation. After irradiation, the mice were killed and their spleens were collected at different time intervals. Tissue samples were stained with hematoxylin-eosin and the numbers of apoptotic cells were scored. Regulating molecules of apoptosis including p53, Bcl-2, Bax, Bcl-XL, and Bcl-XS were also analyzed by Western blotting. RESULTS: At 25 Gy irradiation, the level of apoptosis reached the peak value at 8 hr after radiation and recovered to the normal value at 24 hr after radiation in MRL/Mpj mice. In contrast, the peak apoptosis level appeared at 4 hr after radiation in MRL/Mpj-Fas(lpr) mice. At 8 hr after radiation, the levels of apoptosis in MRL/Mpj mice and MRL/Mpj-Fas(lpr) mice were 52.3+/-7.8% and 8.0+/-8.6%, respectively (p<0.05). The expression of apoptosis regulating molecules, p53, Bcl-XL and Bcl-XS, increased in MRL/Mpj mice in response to radiation; p53 with a peak level of 3-fold at 8 h, Bcl-XL with a peak level of 3.3-fold at 12 h, and Bcl-XS with a peak level of 3-fold at 12 h after 25 Gy radiation. Bcl-2 and Bax did not show significant change in MRL/Mpj mice. However in MRL/Mpj-Fas(lpr) mice, the expression levels of p53, Bcl-2, Bax, Bcl-XL and Bcl-XS showed no significant change. CONCLUSION: The level of radiation-induced apoptosis was lower in Fas mutated mice, lpr, than in control mice. This seemed to be related to the lack of radiation-induced p53 activation in the lpr mice. This result suggests that Fas plays an important role in radiation-induced apoptosis in vivo.
Animals ; Apoptosis* ; Blotting, Western ; Fas Ligand Protein ; Humans ; Male ; Mice ; Radiation Dosage ; Reference Values ; Spleen ; Whole-Body Irradiation