ABSTRACT
BACKGROUND: Gliomas are the most common intrinsic tumors of the brain, with an incidence of 6 per 100 000 persons per year. Recent years have seen marked changes in the diagnosis and treatment of gliomas, with molecular parameters now being an integral part of the diagnostic evaluation. METHODS: This review is based on pertinent articles retrieved by a selective search in PubMed, with special attention to the new WHO glioma classification. RESULTS: The classification of gliomas on the basis of additional molecular parameters enables more accurate prognostication and serves as a basis for therapeutic decision-making and treatment according to precisely specified algorithms. PET scanning with 18F-fluoroethyl tyrosine and 11C-methionine for the measurement of metabolic activity in gliomas has further refined the diagnostic evaluation. The median overall survival of patients with glioblastoma who have undergone resection of all tumor tissue with a disrupted blood-brain barrier (i.e., all contrast-enhancing tumor tissue) has been prolonged to up to 20 months. The 5-year survival of patients with WHO grade II gliomas is now as high as 97% after near-total resection. The surgical resection of all contrast-enhancing tumor tissue and subsequent radiotherapy and chemotherapy remain the key elements of treatment. New surgical strategies and new methods of planning radiotherapy have made these techniques safer and more effective. The percutaneous application of tumor-treating fields is a new therapeutic option that has gained a degree of acceptance. Accompanying measures such as psycho-oncology and palliative care are very important for patients and should be considered mandatory. CONCLUSION: The consistent application of the existing multimodal treatment options for glioma has led in recent years to improved survival. Areas of important current and future scientific activity include immunotherapy and targeted and combined chemotherapy, as well as altered neurocognition, modern approaches to palliative care, and complementary therapies.
Subject(s)
Glioma/classification , Adult , Aged , Contrast Media/therapeutic use , DNA Modification Methylases/analysis , DNA Modification Methylases/blood , DNA Repair Enzymes/analysis , DNA Repair Enzymes/blood , Decision Support Techniques , Female , Glioma/diagnosis , Glioma/genetics , Histone Deacetylases/analysis , Histone Deacetylases/blood , Humans , Isocitrate Dehydrogenase/analysis , Isocitrate Dehydrogenase/blood , Male , Middle Aged , Positron-Emission Tomography/methods , Stereotaxic Techniques , Tumor Suppressor Proteins/analysis , Tumor Suppressor Proteins/blood , World Health Organization/organization & administrationABSTRACT
Taking advantage of "Y" junction structure and restriction endonuclease assisted cyclic enzymatic amplification, a dual-probe electrochemical DNA (DE-DNA) biosensor was designed to detect double-stranded DNA (dsDNA) of acute promyelocytic leukemia (APL) related gene. Two groups of detection probes were designed, and each group was composed of a biotinylated capture probe and an assisted probe. They were separately complementary with two strands of target dsDNA in order to prevent the reannealing of the two separate strands from target dsDNA. First, thiol functionalized capture probes (C1 and C2) were severally assembled onto two different gold electrodes, followed by hybridizing with target dsDNA (S1a-S1b) and assistant probes to form two Y-junction-structure ternary complexes. Subsequently, restriction sites on the ternary complexes were digested by Rsa I, which can release S1a, S1b and biotins from the electrode surfaces. Meanwhile, the released S1a and S1b can further hybridize with the unhybridized corresponding detection probes and then initiate another new hybridization-cleavage-separation cycle. Finally, the current signals were produced by the enzyme-catalyzed reaction of streptavidin-horse reddish peroxidase (streptavidin-HRP). The distinct difference in current signals between different sequences allowed detection of target dsDNA down to a low detection limit of 47 fM and presented excellent specificity with discriminating only a single-base mismatched dsDNA sequence. Moreover, this biosensor was also used for assay of polymerase chain reaction (PCR) samples with satisfactory results. According to the results, the power of the DE-DNA biosensor as a promising tool for the detection of APL and other diseases.
Subject(s)
Conductometry/instrumentation , DNA Probes/genetics , DNA/genetics , Nuclear Proteins/genetics , Oligonucleotide Array Sequence Analysis/instrumentation , Receptors, Retinoic Acid/genetics , Transcription Factors/genetics , Tumor Suppressor Proteins/genetics , Base Sequence , DNA/analysis , DNA/chemistry , DNA Probes/chemistry , DNA Restriction Enzymes/chemistry , DNA Restriction Enzymes/genetics , Equipment Design , Equipment Failure Analysis , Molecular Sequence Data , Nuclear Proteins/analysis , Nuclear Proteins/chemistry , Nucleic Acid Amplification Techniques/instrumentation , Promyelocytic Leukemia Protein , Receptors, Retinoic Acid/analysis , Receptors, Retinoic Acid/chemistry , Recombinant Fusion Proteins/analysis , Recombinant Fusion Proteins/genetics , Reproducibility of Results , Retinoic Acid Receptor alpha , Sensitivity and Specificity , Sequence Analysis, DNA/instrumentation , Transcription Factors/analysis , Transcription Factors/chemistry , Tumor Suppressor Proteins/analysis , Tumor Suppressor Proteins/chemistryABSTRACT
OBJECTIVES: Survival and response to platinum-based induction chemotherapy are heterogeneous among patients with malignant pleural mesothelioma. The aim of the present study was to assess the prognostic role of DNA repair markers, such as excision repair cross-complementation group 1 and ribonucleotide reductase M1, in multimodally treated patients with malignant pleural mesothelioma. METHODS: Tumor tissue of a malignant pleural mesothelioma cohort (n = 107) treated with platinum/gemcitabine (n = 46) or platinum/pemetrexed (n = 61) induction chemotherapy followed by extrapleural pneumonectomy was assembled on a tissue microarray. Immunohistochemical expression of excision repair cross-complementation group 1 (nuclear) and ribonucleotide reductase M1 (nuclear and cytoplasmic) was assessed for its prognostic impact (association with overall survival or freedom from recurrence). RESULTS: Patients with high nuclear ribonucleotide reductase M1 expression before chemotherapy showed significantly longer freedom from recurrence (P = .03). When specifically analyzed in the subgroup of patients receiving platinum/gemcitabine followed by extrapleural pneumonectomy, high nuclear ribonucleotide reductase M1 was associated with prolonged freedom from recurrence (P = .03) and overall survival (P = .02). Low excision repair cross-complementation group 1 expression in prechemotherapy tumor tissues was associated with significantly longer freedom from recurrence (P = .04). Nuclear ribonucleotide reductase M1 and excision repair cross-complementation group 1 were independent prognosticators of freedom from recurrence in addition to pT stage in multivariate analysis. CONCLUSIONS: In the present study, nuclear ribonucleotide reductase M1 and excision repair cross-complementation group 1 expression were identified as independent prognosticators for freedom from recurrence of malignant pleural mesothelioma in patients undergoing induction chemotherapy followed by extrapleural pneumonectomy.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Biomarkers, Tumor/analysis , DNA-Binding Proteins/analysis , Endonucleases/analysis , Lung Neoplasms/therapy , Mesothelioma/therapy , Neoadjuvant Therapy , Pleural Neoplasms/therapy , Pneumonectomy , Tumor Suppressor Proteins/analysis , Chemotherapy, Adjuvant , Deoxycytidine/administration & dosage , Deoxycytidine/analogs & derivatives , Disease Progression , Disease-Free Survival , Female , Glutamates/administration & dosage , Guanine/administration & dosage , Guanine/analogs & derivatives , Humans , Immunohistochemistry , Kaplan-Meier Estimate , Lung Neoplasms/enzymology , Lung Neoplasms/mortality , Lung Neoplasms/pathology , Male , Mesothelioma/enzymology , Mesothelioma/mortality , Mesothelioma/pathology , Mesothelioma, Malignant , Middle Aged , Multivariate Analysis , Neoplasm Recurrence, Local , Neoplasm Staging , Pemetrexed , Platinum Compounds/administration & dosage , Pleural Neoplasms/enzymology , Pleural Neoplasms/mortality , Pleural Neoplasms/pathology , Predictive Value of Tests , Proportional Hazards Models , Ribonucleoside Diphosphate Reductase , Risk Factors , Time Factors , Tissue Array Analysis , Treatment Outcome , GemcitabineSubject(s)
Antigens, CD/analysis , Antigens, Differentiation, Myelomonocytic/analysis , Blood Vessels/pathology , Macrophages/immunology , Nuclear Proteins/analysis , Simian Acquired Immunodeficiency Syndrome/pathology , Thalamus/pathology , Transcription Factors/analysis , Tumor Suppressor Proteins/analysis , Animals , Blood Vessels/immunology , Macaca nemestrina , Macrophages/chemistry , Promyelocytic Leukemia Protein , Simian Acquired Immunodeficiency Syndrome/immunology , Thalamus/immunologySubject(s)
Adenosine Triphosphate/metabolism , Antineoplastic Agents/therapeutic use , Drug Resistance, Neoplasm , Drug Screening Assays, Antitumor , Pancreatic Neoplasms/drug therapy , Adolescent , Adult , Cell Survival/drug effects , Chemotherapy, Adjuvant , DNA-Binding Proteins/analysis , DNA-Binding Proteins/genetics , Endonucleases/analysis , Endonucleases/genetics , Feasibility Studies , Female , Humans , Immunohistochemistry , Japan , Male , Middle Aged , Multidrug Resistance-Associated Protein 2 , Multidrug Resistance-Associated Proteins/analysis , Multidrug Resistance-Associated Proteins/genetics , Pancreatectomy , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/metabolism , Pancreatic Neoplasms/pathology , Pancreatic Neoplasms/surgery , Patient Selection , Retrospective Studies , Reverse Transcriptase Polymerase Chain Reaction , Ribonucleoside Diphosphate Reductase , Tumor Suppressor Proteins/analysis , Tumor Suppressor Proteins/genetics , Young AdultABSTRACT
Parathyroid cancer is an uncommon malignancy and rare cause of primary hyperparathyroidism (HPT) with a high morbidity and patient death in advanced cases usually resulting from intractable hypercalcemia. Inactivation of the HRPT2/CDC73 gene, encoding the putative tumor-suppressor protein parafibromin and discovered in the context of the hyperparathyroidism-jaw tumor (HPT-JT) syndrome, is a common, somatic event in most parathyroid cancers. Approximately 25% of patients with apparently sporadic parathyroid cancer carry germline HRPT2/CDC73 mutation. Germline DNA analysis for HRPT2/CDC73 mutation is recommended in all patients with parathyroid cancer because of the potential benefit for first-degree relatives, who should nevertheless undergo serum calcium screening. The histopathologic diagnosis of parathyroid cancer is nonspecific unless vascular, lymphatic, capsular, or soft tissue invasion is seen, or metastases are clinically evident. Immunohistochemical analysis of parathyroid tumors for loss of parafibromin expression offers promise as a diagnostic tool. En bloc tumor resection offers the highest chance of cure in patients with suspected parathyroid carcinoma. No adjuvant chemotherapy regimen has yet proven effective, and the role of local adjuvant radiotherapy is being evaluated. Metastatic disease can be palliated with surgical debulking. Medical therapy with the calcimimetic cinacalcet and bisphosphonates can ameliorate hypercalcemia in patients with inoperable disease.
Subject(s)
Parathyroid Neoplasms/pathology , Parathyroid Neoplasms/therapy , Biomarkers, Tumor , Disease Progression , Humans , Hypercalcemia/etiology , Mutation , Parathyroid Neoplasms/complications , Parathyroid Neoplasms/genetics , Parathyroidectomy , Prognosis , Tumor Suppressor Proteins/analysis , Tumor Suppressor Proteins/geneticsABSTRACT
BACKGROUND: Acid reflux is often difficult to control medically. AIM: To assess the effect of 40 mg twice daily esomeprazole (high-dose) on gastric and oesophageal pH and symptoms, and biomarkers relevant to adenocarcinoma, in patients with Barrett's oesophagus (BO). METHODS: Eighteen patients, treated with proton pump inhibitors as prescribed by their treating doctor, had their therapy increased to high-dose esomeprazole for 6 months. RESULTS: At entry into the study, 9/18 patients had excessive 24-h oesophageal acid exposure, and gastric pH remained <4 for >16 h in 8/18. With high-dose esomeprazole, excessive acid exposure occurred in 2/18 patients, and gastric pH <4 was decreased from 38% of overall recording time and 53% of the nocturnal period to 15% and 17%, respectively (P < 0.001). There was a reduction in self-assessed symptoms of heartburn (P = 0.0005) and regurgitation (P < 0.0001), and inflammation and proliferation in the Barrett's mucosa. There was no significant change in p53, MGMT or COX-2 expression, or in aberrant DNA methylation. CONCLUSIONS: High-dose esomeprazole achieved higher levels of gastric acid suppression and control of oesophageal acid reflux and symptoms, with significant decreases in inflammation and epithelial proliferation. There was no reversal of aberrant DNA methylation.
Subject(s)
Anti-Ulcer Agents/therapeutic use , Barrett Esophagus/drug therapy , Esomeprazole/therapeutic use , Proton Pump Inhibitors , Proton Pump Inhibitors/therapeutic use , Adult , Aged , Anti-Ulcer Agents/administration & dosage , Barrett Esophagus/genetics , Barrett Esophagus/physiopathology , Biopsy , Cell Proliferation/drug effects , DNA Methylation , Esomeprazole/administration & dosage , Esophagus/pathology , Esophagus/physiology , Female , Humans , Hydrogen-Ion Concentration , Inflammation , Male , Middle Aged , Mucous Membrane/cytology , Mucous Membrane/pathology , Proton Pump Inhibitors/administration & dosage , Stomach/physiology , Tumor Suppressor Proteins/analysisABSTRACT
INTRODUCTION: Stem cell lines are usually grown in medium containing animal products. Fetal bovine serum (FBS) is an important additive for cell growth; however, the allergenic potential and the possibility of contamination when we use a medium containing serum would be a barrier to transplantation and consequently to the introduction of cell therapy methods into clinical applications. METHODS: Dental mesenchymal cells were isolated and expanded in vitro and maintained in 4 different serum-free media (SFMs): SFM#1 (ITS-X, embryotrophic factor [ETF]); SFM#2 (ITS-X); SFM#3 (ETF); and SFM#4 (ETF, sodium pyruvate, ascorbic acid, fibroblast growth factor [FGF-a], acidic). Viability, proliferative, and immunocytochemical tests for the cells were performed by using 4 stem cell markers (CD44H, CK19, nestin, and P63) for ectoderm, mesoderm, and endoderm. RESULTS: Viability tests showed a significant difference between the control and SFMs in both deciduous tooth pulp cells (DTPCs) and wisdom tooth pulp cells (WTPCs). However, all SFMs demonstrated 84%-90% viability, whereas the control showed 90%-93%. In both DTPCs and WTPCs, SFM#1 had the highest proliferation rate among the 4 SFMs. Immunocytochemistry stained positive stem cell markers most intensely in cells cultured with SFM#1. Furthermore, all stem cell markers for ectoderm, mesoderm, and endoderm were expressed in the cells cultured with SFM#1. CONCLUSIONS: SFM#1 showed an acceptable survival rate, the highest proliferation rate, and the strongest expression of all the stem cell markers. SFM#1 proved to be a suitable medium for the culture of human dental pulp stem cells and to preserve pluripotency in differentiation.
Subject(s)
Cell Culture Techniques , Culture Media, Serum-Free , Dental Pulp/cytology , Mesenchymal Stem Cells/physiology , Animals , Ascorbic Acid/pharmacology , Biomarkers/analysis , Cattle , Cell Count , Cell Proliferation/drug effects , Cell Survival/drug effects , Culture Media , Dental Pulp/drug effects , Ectoderm/cytology , Endoderm/cytology , Fibroblast Growth Factor 1/pharmacology , Humans , Hyaluronan Receptors/analysis , Insulin/pharmacology , Intercellular Signaling Peptides and Proteins/pharmacology , Intermediate Filament Proteins/analysis , Keratin-19/analysis , Mesenchymal Stem Cells/drug effects , Mesoderm/cytology , Molar, Third/cytology , Nerve Tissue Proteins/analysis , Nestin , Pyruvic Acid/pharmacology , Selenium/pharmacology , Tooth, Deciduous/cytology , Trans-Activators/analysis , Transcription Factors , Transferrin/pharmacology , Tumor Suppressor Proteins/analysisABSTRACT
Kisspeptins are a recently identified class of neuropeptides belonging to the RFamide peptide family. Despite growing evidence supporting kisspeptin as a key regulator of reproduction, data addressing whether kisspeptin is a conserved reproductive signal are lacking. We investigated the distribution of kisspeptin in adult green anole lizards (Anolis carolinensis) via immunohistochemistry. Additionally, we examined the possibility of a sexual dimorphism in kisspeptin expression. Kisspeptin immunoreactivity was observed rostrally in the preoptic area and caudally in an area lateral to the dorsal hypothalamic nucleus in both male and female anoles. These kisspeptin immunoreactive cells are associated with vesiculated fibers traveling through the paraventricular zone of the hypothalamus and preoptic area and extending into the rostral telencephalon. Preabsorption of the antiserum with gonadotropin inhibitory hormone (GnIH), a second RFamide peptide known to cross-react with the kisspeptin antiserum, eliminated staining of the caudal population of cells but retained staining in the rostral population, suggesting that kisspeptin is present in this area. Preabsorption with kisspeptin eliminated all immunoreactivity. These preabsorption results suggest that kisspeptin is restricted to a single population in the preoptic area in anoles. No sex differences were found in kisspeptin immunoreactive cell number. The presence of kisspeptin RFamide peptide in the green anole suggests that this reproductive regulatory signal is indeed evolutionarily conserved. Whether this reproductive signal functions similarly in regulating the reproductive axis of ectotherms requires further study.
Subject(s)
Brain/cytology , Brain/metabolism , Lizards/anatomy & histology , Lizards/metabolism , Neurons/metabolism , Neuropeptides/metabolism , Animals , Brain Mapping , Conserved Sequence/physiology , Evolution, Molecular , Female , Gonadotropin-Releasing Hormone/metabolism , Hypothalamus/cytology , Hypothalamus/metabolism , Immunohistochemistry/methods , Kisspeptins , Male , Neural Pathways/cytology , Neural Pathways/metabolism , Neuropeptides/analysis , Preoptic Area/cytology , Preoptic Area/metabolism , Reproduction/physiology , Sex Characteristics , Sexual Behavior, Animal/physiology , Species Specificity , Tumor Suppressor Proteins/analysis , Tumor Suppressor Proteins/metabolismABSTRACT
Kisspeptin and its receptor GPR54 play important roles in mammalian reproduction and cancer metastasis. Because the KiSS and GPR54 genes have been identified in a limited number of vertebrate species, mainly in mammals, the evolutionary history of these genes is poorly understood. In the present study, we have cloned multiple forms of kisspeptin and GPR54 cDNAs from a variety of vertebrate species. We found that fish have two forms of kisspeptin genes, KiSS-1 and KiSS-2, whereas Xenopus possesses three forms of kisspeptin genes, KiSS-1a, KiSS-1b, and KiSS-2. The nonmammalian KiSS-1 gene was found to be the ortholog of the mammalian KiSS-1 gene, whereas the KiSS-2 gene is a novel form, encoding a C-terminally amidated dodecapeptide in the Xenopus brain. This study is the first to identify a mature form of KiSS-2 product in the brain of any vertebrate. Likewise, fish possess two receptors, GPR54-1 and GPR54-2, whereas Xenopus carry three receptors, GPR54-1a, GPR54-1b, and GPR54-2. Sequence identity and genome synteny analyses indicate that Xenopus GPR54-1a is a human GPR54 ortholog, whereas Xenopus GPR54-1b is a fish GPR54-1 ortholog. Both kisspeptins and GPR54s were abundantly expressed in the Xenopus brain, notably in the hypothalamus, suggesting that these ligand-receptor pairs have neuroendocrine and neuromodulatory roles. Synthetic KiSS-1 and KiSS-2 peptides activated GPR54s expressed in CV-1 cells with different potencies, indicating differential ligand selectivity. These data shed new light on the molecular evolution of the kisspeptin-GPR54 system in vertebrates.
Subject(s)
Evolution, Molecular , Receptors, G-Protein-Coupled/analysis , Receptors, G-Protein-Coupled/genetics , Tumor Suppressor Proteins/analysis , Tumor Suppressor Proteins/genetics , Vertebrates , Amino Acid Sequence , Animals , DNA, Complementary/genetics , Female , Humans , Hypothalamus/metabolism , Kisspeptins , Lampreys , Lizards , Male , Mice , Molecular Sequence Data , Oryzias , Phylogeny , Platypus , Protein Isoforms/analysis , Protein Isoforms/genetics , Protein Isoforms/metabolism , RNA, Messenger/metabolism , Receptors, G-Protein-Coupled/metabolism , Receptors, Kisspeptin-1 , Sharks , Tumor Suppressor Proteins/metabolism , Xenopus , ZebrafishABSTRACT
OBJECTIVES: We sought to ascertain whether chronic oral therapy with atorvastatin protects against ischemia/reperfusion (I/R) injury. BACKGROUND: We have recently shown that acute atorvastatin treatment protects against reperfusion-induced injury by activating the PI3K/Akt/eNOS pathway. However, many patients are on chronic statin therapy, and it is necessary to investigate whether this, in itself, provides a therapeutic advantage. METHODS: Sprague-Dawley rats were orally treated for one day, three days, one week, or two weeks with 20 mg/kg of atorvastatin or vehicle, after which the hearts underwent 35 min of ischemia and 120 min reperfusion (IR). Two additional groups were treated for one or two weeks with atorvastatin and then received a supplementary dose of 40 mg/kg before IR. The risk zone was determined using Evans blue and infarct size (IR%) using triphenyltetrazolium chloride staining. RESULTS: Treatment with atorvastatin for one and three days significantly reduced infarct size versus controls (38.9 +/- 3.1% vs. 56.4 +/- 2.3%; 39.3 +/- 2.4% vs. 61.3 +/- 3.8%, respectively). However, after one or two weeks of treatment, no protection was observed (52.6 +/- 3.8% vs. 58.6 +/- 4.3%; 58.3 +/- 2.7% vs. 52.4 +/- 5.7%, respectively). Surprisingly, a supplementary dose of atorvastatin recaptured the protection in the groups treated chronically (36.2 +/- 2.8% vs. 58.6 +/- 4.3%; 26.8 +/- 1.5% vs. 51.2 +/- 6.7%, at one and two weeks, respectively). Interestingly, we observed an increased level of phosphatase and tensin homolog deleted on chromosome ten (PTEN), the phosphatidylinositol-3 kinase inhibitor, in the chronic treated hearts. CONCLUSIONS: In conclusion, atorvastatin appears to have an acute protective effect that wanes with time associated with an increase in PTEN levels. This waning protection can be recaptured by an acute high dose given immediately before IR. These results may have protential clinical relevance.
Subject(s)
Heptanoic Acids/administration & dosage , Hydroxymethylglutaryl-CoA Reductase Inhibitors/administration & dosage , Phosphoric Monoester Hydrolases/physiology , Pyrroles/administration & dosage , Reperfusion Injury/prevention & control , Tumor Suppressor Proteins/physiology , Animals , Atorvastatin , Blotting, Western , Male , PTEN Phosphohydrolase , Phosphatidylinositol 3-Kinases/metabolism , Phosphoric Monoester Hydrolases/analysis , Protein Serine-Threonine Kinases/metabolism , Proto-Oncogene Proteins/metabolism , Proto-Oncogene Proteins c-akt , Rats , Rats, Sprague-Dawley , Tumor Suppressor Proteins/analysisABSTRACT
OBJECTIVE: To investigate the role of p27 in the inhibition of emodin on the mesangial cell (MC) proliferation induced by tumor necrosis factor-alpha(TNF-alpha). METHODS: p27 protein of MC was detected with western blotting analysis. The degree of MC proliferation was estimated through [(3)H] thymidine ([(3)H] TdR) incorporation. Different dosage of emodin (50 mg/L,100 mg/L) was added into MC stimulated by TNF-alpha. RESULTS: TNF-alpha (200 kU/L) decreased p27 level of MC cultured in serum-free DMEM for 24 hours and increased[(3)H] TdR incorporation. Emodin increased p27 level of MC stimulated by TNF-alpha and decreased [(3)H] TdR incorporation. The more the emodin was added, the greater the above-mentioned effect of emodin. CONCLUSION: The increment of p27 level maybe play an important role in the inhibition of emodin on MC proliferation induced by TNF-alpha.
Subject(s)
Cell Cycle Proteins/physiology , Emodin/antagonists & inhibitors , Glomerular Mesangium/drug effects , Tumor Necrosis Factor-alpha/pharmacology , Tumor Suppressor Proteins/physiology , Animals , Cell Cycle Proteins/analysis , Cell Division/drug effects , Cells, Cultured , Cyclin-Dependent Kinase Inhibitor p27 , Glomerular Mesangium/cytology , Rats , Rats, Sprague-Dawley , Tumor Suppressor Proteins/analysisABSTRACT
OBJECT: Ionizing radiation is the gold-standard adjuvant treatment for glioblastoma multiforme (GBM), the most aggressive primary brain tumor. The mechanisms underlying neoplastic glial cell growth inhibition after administration of ionizing radiation, however, remain largely unknown. In this report, the authors characterize the response of GBM cells to ionizing radiation and elucidate factors that correlate with the radiosensitivity of these tumors. METHODS: Six human GBM cell lines were subjected to increasing doses of radiation. Each demonstrated a dose-dependent suppression of cell proliferation. In the most radiosensitive cell line, the authors demonstrated a transient increase in the expression of the cyclin-dependent kinase inhibitors (CDKIs) p21 and p27, which corresponded with a G1 cell-cycle arrest. In contrast, the most radioresistant cell line demonstrated a decrease in p21 and p27 expression levels, which correlated with a failure to arrest. Apoptosis did not occur in any cell line following irradiation. Instead, autophagic cell changes were observed following administration of radiation, regardless of the relative radiosensitivity of the cell line. CONCLUSIONS: These findings elucidate some of the molecular responses of GBMs to irradiation and suggest novel targets for future therapy.
Subject(s)
Autophagy/genetics , Autophagy/radiation effects , Brain Neoplasms/pathology , Brain Neoplasms/radiotherapy , Cell Cycle Proteins/radiation effects , Cyclins/radiation effects , Enzyme Inhibitors/radiation effects , G1 Phase/genetics , G1 Phase/radiation effects , Glioblastoma/pathology , Glioblastoma/radiotherapy , Radiation, Ionizing , Tumor Suppressor Proteins/radiation effects , Brain Neoplasms/genetics , Cell Cycle Proteins/analysis , Cyclin-Dependent Kinase Inhibitor p21 , Cyclin-Dependent Kinase Inhibitor p27 , Cyclins/analysis , Enzyme Inhibitors/analysis , Glioblastoma/genetics , Humans , In Situ Nick-End Labeling , In Vitro Techniques , Organelles/genetics , Organelles/radiation effects , Radiation Tolerance/genetics , Radiation Tolerance/radiation effects , Time Factors , Tumor Cells, Cultured/pathology , Tumor Cells, Cultured/radiation effects , Tumor Suppressor Proteins/analysisABSTRACT
Previously we have shown that changes in maternal dietary choline are associated with permanent behavioral changes in offspring. Importantly, in adult male rats, feeding a choline-deficient diet increases the localization of cyclin-dependent kinase inhibitors (CDKIs) in the liver, whereas young adult CDKI knockout mice (p15Ink4B or p27Kip1) exhibit behavioral abnormalities. Thus, maternal dietary choline-CDKI interactions could underlie the changes we observe in fetal hippocampal development and cognitive function in offspring. Here, timed-pregnant rats on embryonic day E12 were fed the AIN-76 diet with varying levels of dietary choline for 6 days, and, on E18, fetal brain sections were collected, and the localization of CDKI proteins was studied using immunohistochemistry and an unbiased image analysis method. In choline-supplemented animals compared to controls, the number of cells with nuclear immunoreactivity for p15Ink4b CDKI protein was decreased 2- to 3-fold in neuroepithelial ventricular zones and adjacent subventricular zones corresponding to the fimbria, primordial dentate gyrus and Ammon's horn regions in the fetal hippocampus. In contrast, maternal dietary choline deficiency significantly decreased nuclear p15Ink4b immunoreactivity in the neuroepithelial layer of the dentate gyrus. Unlike p15Ink4b, the CDKI protein p27Kip1 was observed almost exclusively in the cytoplasm, though the protein was distributed throughout the proliferating and postmitotic zones in the E18 fetal hippocampus. Maternal dietary choline supplementation decreased the cytoplasmic staining intensity for p27Kip1 throughout the fetal hippocampus compared to control animals. Choline deficiency increased the staining intensity of p27Kip1 throughout the hippocampus in association with increased expression of MAP-1 and vimentin proteins. These results link maternal dietary choline availability to CDKI protein immunoreactivity and commitment to differentiation during fetal hippocampal development.