An Experimental Study of Radiation Effect on Normal Tissue: Analysis of HIF-1α, VEGF, eIF2, TIA-1, and TSP-1 Expression.

OBJECTIVE: This study investigated whether or not the stress and hypoxia, which are the effects of radiation on normal vascular endothelium, leading to the release of HIF-1α, VEGF, eIF2, TIA-1, and TSP-1 were related and the possibility of them stimulating angiogenesis. MATERIALS AND METHODS: Twenty-four male Swiss Albino mice were separated into 4 groups. The first group was the control group (Group 1), and the second, third, and fourth groups were euthanized after 24 h (Group 2), 48 h (Group 3), and 7 days (Group 4), respectively. A single-fractioned 10 Gy of ionizing radiation was applied to all mice's pelvic zone with Co-60. Bladders were removed completely from the pelvic region. Immunohistochemistry and light microscopy were used to investigate whether there would be an increase or not in the angiogenesis pathway by using the HIF-1α, VEGF, eIF2, TIA-1, and TSP-1 antibodies. RESULTS: The HIF-1α antibody showed strong staining in Group 3, while the staining intensity was less in other groups. VEGF showed weak staining in Groups 1 and 4, while moderate staining in Group 2 and strong staining in Group 3 was observed. eIF2 showed strong staining in Groups 1 and 4. Groups 2 and 3 were stained weakly. In the present study, staining with TSP-1 was very strong in the samples belonging to Group 1, while other groups showed very weak staining. CONCLUSION: When normal tissue was exposed to radiation, the positively effective factors (HIF-1, VEGF, eIF2, and TIA-1) on the angiogenesis pathway were increased while the negative factor (TSP-1) was decreased. Radiation may initiate physiological angiogenesis in the normal tissue and accelerate healing in the damaged normal tissue. CONFLICT OF INTEREST: None declared.

A New Prognostic Parameter Associated With Recurrence in Patients With Nasopharyngeal Cancer Treated With Chemoradiotherapy: The Ratio of the Hemoglobin-to-Red Cell Distribution Width.

INTRODUCTION: This study aims to investigate the prognostic significance of the pre-treatment hemoglobin-red blood cell distribution width (RDW) ratio (HRR) in terms of overall survival (OS) and disease-free survival (DFS) in patients with locally advanced nasopharyngeal cancer (LANC) treated with chemoradiotherapy. METHODS: Patients with LANC who attended the oncology clinic between October 2010 and June 2020 were retrospectively screened. HRR was calculated as hemoglobin (g/dL) divided by the RDW (%). Patients were assigned to either the low HRR group or the high HRR group. RESULTS: A total of 102 patients were included in the study. The cut-off value for HRR was taken as 0.97. Between the low and high HRR groups, mean age, Eastern Cooperative Oncology Group (ECOG) performance score, gamma-glutamyl transferase (GGT), albumin and lactate dehydrogenase (LDH) levels, weight loss at diagnosis, and recurrence and metastasis rate were significantly different. In the low HRR group, OS and DFS were 44.4 (95% CI: 4.9-83.8) and 15.7 months (95% CI: 0.1-36.2), respectively, but could not be reached in the high HRR group (p<0.001). In the multivariate analysis, low HRR was shown to be an independent factor in terms of both OS (p=0.004, hazard ratio (HR)=3.07, 95% CI: 1.444-6.529) and DFS (p<0.001, HR=3.94, 95% CI: 1.883-8.244). CONCLUSION: This is the first study showing that HRR is an independent prognostic marker for OS and DFS in patients with LANC treated with chemoradiotherapy. Thus, HRR can be used as an easily applicable, inexpensive marker in clinical practice in this patient group.

Proteomic analysis of a hom-disrupted, cephamycin C overproducing Streptomyces clavuligerus.

BACKGROUND: Streptomyces clavuligerus is prolific producer of cephamycin C, a medically important antibiotic. In our former study, cephamycin C titer was 2-fold improved by disrupting homoserine dehydrogenase (hom) gene of aspartate pahway in Streptomyces clavuligerus NRRL 3585. OBJECTIVE: In this article, we aimed to provide a comprehensive understanding at the proteome level on potential complex metabolic changes as a consequence of hom disruption in Streptomyces clavuligerus AK39. METHODS: A comparative proteomics study was carried out between the wild type and its hom disrupted AK39 strain by 2 Dimensional Electrophoresis-Matrix Assisted Laser Desorption and Ionization Time-Of-Flight Mass Spectrometry (2DE MALDI-TOF/MS) and Nanoscale Liquid Chromatography- Tandem Mass Spectrometry (nanoLC-MS/MS) analyses. Clusters of Orthologous Groups (COG) database was used to determine the functional categories of the proteins. The theoretical pI and Mw values of the proteins were calculated using Expasy pI/Mw tool. RESULTS: "Hypothetical/Unknown" and "Secondary Metabolism" were the most prominent categories of the differentially expressed proteins. Upto 8.7-fold increased level of the positive regulator CcaR was a key finding since CcaR was shown to bind to cefF promoter thereby direcly controlling its expression. Consistently, CeaS2, the first enzyme of CA biosynthetic pathway, was 3.3- fold elevated. There were also many underrepresented proteins associated with the biosynthesis of several Non-Ribosomal Peptide Synthases (NRPSs), clavams, hybrid NRPS/Polyketide synthases (PKSs) and tunicamycin. The most conspicuously underrepresented protein of amino acid metabolism was 4-Hydroxyphenylpyruvate dioxygenase (HppD) acting in tyrosine catabolism. The levels of a Two Component System (TCS) response regulator containing a CheY-like receiver domain and an HTH DNA-binding domain as well as DNA-binding protein HU were elevated while a TetR-family transcriptional regulator was underexpressed. CONCLUSION: The results obtained herein will aid in finding out new targets for further improvement of cephamycin C production in Streptomyces clavuligerus.

Influence of Radiation Exposure During Radiotherapy. Evidence for the Increase of Versican and Heparin-Binding EGF-like Growth Factor Concentrations.

OBJECTIVE: To investigate the reaction of versican and heparin-binding EGF-like growth factor (HB-EGF) molecule concentrations to acute radiation exposure in normal bladder and rectal tissue samples in order to gain more insight into the effects of cancer radiotherapy. STUDY DESIGN: Four groups with 6 male adult Swiss Albino mice per group were investigated. The mice bladder and rectum tissue samples were subjected to a 10-Gy single-dose radiation exposure in the pelvic region with a Co-60 teletherapy device and investigated 1, 2, and 7 days after radiation exposure, with 1 reference group which was not exposed to radiation. RESULTS: In the immunohistochemical examination of the tissue samples with anti-versican and anti-HB-EGF primary antibodies was observed a statistically significant increase 7 days after radiation exposure. CONCLUSION: The observed increase of versican and HB-EGF concentrations in the normal tissue matrix after radiation exposure may play a role in the side effects of radiotherapy.

Effects of Cyclooxygenase on the Urothelium of the Urinary Bladder of Mice Exposed to Pelvic Radiation.

OBJECTIVE: To determine the role of cyclooxygenase (COX) expression in the urothelium of the urinary bladder during radiation injury caused by pelvic radiotherapy for cancer therapy. STUDY DESIGN: Twenty-four male Swiss Albino mice were separated into 4 groups. The first group was the control group (Group 1) and the second, third, and fourth groups were euthanized after 24 hours (Group 2), 48 hours (Group 3), and 7 days (Group 4), respectively. A single-fractioned 10 Gy of ionizing radiation was applied to all mice's pelvic zone with Co-60. Bladders were removed completely from the pelvic region. Histochemical analysis using hematoxylin and eosin and immunohistochemical analysis using anti-COX-1 and COX-2 antibodies were performed on tissue samples. The immunoreactivities of the urinary bladder were quantified using H-score measurement, and statistical comparison was performed. RESULTS: In the immunohistochemical examination the COX-1 immunoreactivities were found to be higher in the urothelium of the bladder in the radiation exposed groups than in the normal control group (group 1) (p < 0.005). Additionally, high immunoreactivity of COX-2 molecule was established in groups 2, 3, and 4 of radiation groups as compared to group 1 (p < 0.005) in examination of the urothelium. COX-1 and COX-2 immunoreactivities in the submucosa were detected higher in group 4 than in the other groups (p < 0.005). CONCLUSION: COX-1 and COX-2 expressions in the urothelium and subepithelium of the urinary bladder were investigated in mice during the acute radiation response. The expression of COX-1 and COX-2 in the urothelium seems to prevent bladder damage from radiation, supplying differentiation and restoration of the urothelium.

Comparison of 2-dimensional and 3-dimensional conformal treatment plans in gastric cancer radiotherapy.

BACKGROUND: Postoperative chemoradiotherapy is accepted as standard treatment for stage IB-IV, M0 gastric cancer. Radiotherapy (RT) planning of gastric cancer is important because of the low radiation tolerance of surrounding critical organs. The purpose of this study was to compare the dosimetric aspects of 2-dimensional (2D) and 3-dimensional (3D) treatment plans, with the twin aims of evaluating the adequacy of 2D planning fields on coverage of planning target volume (PTV) and 3D conformal plans for both covering PTV and reducing the normal tissue doses. MATERIALS AND METHODS: Thirty-six patients with stage II-IV gastric adenocarcinoma were treated with adjuvant chemoradiotherapy using 3DRT. For each patient, a second 2D treatment plan was generated. The two techniques were compared for target volume coverage and dose to normal tissues using dose volume histogram (DVH) analysis. RESULTS: 3DRT provides more adequate coverage of the target volume. Comparative DVHs for the left kidney and spinal cord demonstrate lower radiation doses with the 3D technique. CONCLUSIONS: 3DRT produced better dose distributions and reduced radiation doses to left kidney and spinal cord compared to the 2D technique. For this reason it can be predicted that 3DRT will result in better tumor control and less normal tissue complications.