Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0017636 (glioblastoma)
 18,345 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The authors describe an autopsy case of glioblastoma occurred after 38 years received lobotomy. The patient was a 72 year-old male, who received lobotomy at 34 year old against schizophrenia. CT scan taken at 72 year old showed irregular low density areas without mass effect in the bilateral frontal white matter adjacent to the anterior horn. After 4 months, the signs of intracranial hypertension were observed and his consciousness was disturbed abruptly. CT scan revealed ring enhancement with marked mass effect in the left frontal lobe. A biopsy specimen from the tumor showed a picture of anaplastic astrocytoma. Family rejected the remission maintenance treatment. The patient died 3 months later the onset. At autopsy, a large tumor occupied in the left frontal lobe was recognized. The tumor demarcated poorly from the cerebral tissue and invaded into the left anterior cingulate gyrus and the corpus callosum. Histologically, tumor cells composed of fibrillary, gemistocytic and multinucleated astrocytes. GFAP, NSE and vimentin were found in large cells. Histological diagnosis was glioblastoma. It was suggested that the tumor occurred from the region around a cyst of prefrontal lobotomy in the left frontal lobe. In the right frontal lobe, a large cyst in size of 30-18 mm was present in the centrum semiovale. The wall of cyst was composed of layer of glial scar tissue. The origin of the cyst was discussed.
 ...
PMID:[An autopsy case of glioblastoma occurred in the region after lobotomy]. 207 52

We report a case of glioblastoma manifesting 49 years after a lobotomy. He was diagnosed as having schizophrenia at age 20 and was operated on with a standard lobotomy when he was 27 years old. He had led a useful life after 40 years old without medication. Because of hallucination and delusion, he was hospitalized at the end of 1996. CT showed a well enhanced tumor adjacent to the cavity made by the lobotomy in the left frontal lobe. This is the second case report of glioblastoma just beside the cavity formed by lobotomy. The relationship between glioblastoma and old lobotomy is discussed, especially in regard to morphology and CT findings.
 ...
PMID:[A case of glioblastoma manifesting 49 years after lobotomy]. 975 70

Papers from a generation ago suggested that phenothiazines--in particular trifluorperazine (Stelazine) a medicinal approved by the FDA and still commonly used for schizophrenia--downregulate the epidermal growth factor receptor. As numerous cancers--e.g., colon cancer, breast cancer, pancreatic cancer and glioblastoma--are dependent on signaling via this receptor, we here suggest that phenothiazines such as trifluorperazine be considered for use in epidermal growth factor receptor associated cancers.
 ...
PMID:Consideration of use of phenothiazines in particular trifluorperazine for epidermal growth factor receptor associated cancers. 1744 10

Human genes coding for pLG72 and d-amino acid oxidase have recently been linked to the onset of schizophrenia. pLG72 was proposed as an activator of the human FAD-containing flavoprotein d-amino acid oxidase (hDAAO). In the brain this oxidizes d-serine, a potent activator of N-methyl-d-aspartate receptor. We have investigated the mechanistic regulation of hDAAO by pLG72. Immunohistochemical analyses revealed that hDAAO and pLG72 are both expressed in astrocytes of the human cortex, where they most likely interact, considering their partial overlapping subcellular distribution and their coimmunoprecipitation. We demonstrated that the specific in vitro interaction of the two proteins yields a complex composed of 2 hDAAO homodimers and 2 pLG72 molecules. Binding of pLG72 did not affect the kinetic properties and FAD binding ability of hDAAO; instead, a time-dependent loss of hDAAO activity in the presence of an excess of pLG72 was found. The binding affects the tertiary structure of hDAAO, altering the amount of the active form. We finally demonstrated that overexpression of hDAAO in glioblastoma cells decreases the levels of d-serine, an effect that is null when pLG72 is coexpressed. These data indicate that pLG72 acts as a negative effector of hDAAO. Therefore, a decrease in the synaptic concentration of d-serine as the result of an anomalous increase in hDAAO activity related to hypoexpression of pLG72 may represent a molecular mechanism by which hDAAO and pLG72 are involved in schizophrenia susceptibility.
 ...
PMID:pLG72 modulates intracellular D-serine levels through its interaction with D-amino acid oxidase: effect on schizophrenia susceptibility. 1854 34

Sometimes patients with organic brain lesions in neurologically silent brain areas might present only with psychiatric symptoms, such as depression, anxiety disorders, schizophrenia, anorexia nervosa, or cognitive dysfunction. This study presents eight cases of patients with brain lesions (four cases of meningiomas, one case of intracerebral cysts, one case of anaplastic oligodendroglioma, one case of multiform glioblastoma, and one case of occlusive hydrocephalus) who, for a significant period of time, were diagnosed and treated for psychiatric disorders (three cases of Alzheimer's disease, two cases of schizoaffective disorder, one case of schizophrenia, one case of depression, and one case of organic emotional lability disorder). When neurologic symptoms developed, they underwent neuroimaging studies and organic brain lesions were diagnosed. Further treatment required neurosurgical interventions. These cases show that brain tumors can be neurologically silent for a sufficient period of time and manifest as psychiatric disorders. Therefore, neuroimaging studies are needed when atypical changes in mental status or neurologic symptoms and signs develop.
 ...
PMID:Brain lesions manifesting as psychiatric disorders: eight cases. 1903 81

Accumulating genetic evidence indicates that the primate-specific gene locus G72/G30 is related to schizophrenia: it encodes for the protein pLG72, whose function is still the subject of controversy. We recently demonstrated that pLG72 negatively affects the activity of human d-amino acid oxidase (hDAAO, also related to schizophrenia susceptibility), which in neurons and (predominantly) in glia is expected to catabolize the neuromodulator d-serine. The d-serine regulation mechanism relying on hDAAO-pLG72 interaction does not match with the subcellular localizations proposed for hDAAO (peroxisomes) and pLG72 (mitochondria). By using glioblastoma U87 cells transfected with plasmids encoding for hDAAO and/or pLG72 we provide convergent lines of evidence that newly synthesized hDAAO, transitorily present in cytosol before being delivered to the peroxisomes, colocalizes and interacts with pLG72 which we propose to be exposed on the external membrane of mitochondria. We also report that newly synthesized cytosolic hDAAO is catalytically active, and therefore pLG72 binding-and ensuing hDAAO inactivation-plays a protective role against d-serine depletion.
 ...
PMID:Evidence for the interaction of D-amino acid oxidase with pLG72 in a glial cell line. 2167 69

Calcium-binding protein S100B has been implicated in the pathology of bipolar affective disorder (BPAD) and schizophrenia (SZ). S100B protein levels are elevated in serum of patients with both disorders compared to controls. We previously reported genetic association of a SNP in the promoter of S100B, rs3788266, with a psychotic form of BPAD. To test for genotypic effects of rs3788266 in vivo, S100B serum protein levels were measured in 350 Irish and German subjects of known S100B genotype. The functional effect of rs3788266 on S100B promoter activity was studied using the luciferase reporter system in U373MG glioblastoma and SH-SY5Y neuroblastoma cell lines. Allelic effects of rs3788266 on protein complex formation at the S100B promoter were investigated by an electrophoretic mobility shift assay. Higher mean serum S100B levels were associated with the risk G allele of rs3788266 in BPAD cases (P = 0.0001), unaffected relatives of BPAD cases (P < 0.0001) and unrelated controls (P < 0.0001). Consistent with the in vivo findings, luciferase gene expression was significantly increased in the presence of the G allele compared to the A allele in SH-SY5Y (P = <0.0001), and in U373MG (P = <0.0008) cell lines. The binding affinity of both SH-SY5Y and U373MG protein complexes for the S100B promoter was significantly stronger in the presence of G allele compared to the A allele promoter fragments. These data support rs3788266 as a functional promoter variant in the S100B gene where the presence of the G allele promotes increased gene expression and is associated with increased serum levels of the protein.
 ...
PMID:Functional assessment of a promoter polymorphism in S100B, a putative risk variant for bipolar disorder. 2171 70

D-Amino acid oxidase (DAAO; EC1.4.3.3) has been proposed to play a main role in the degradation of D-serine, an allosteric activator of the N-methyl-D-aspartate-type glutamate receptor in the human brain, and to be associated with the onset of schizophrenia. To prevent excessive D-serine degradation, novel drugs for schizophrenia treatment based on DAAO inhibition were designed and tested on rats. However, the properties of rat DAAO are unknown and various in vivo trials have demonstrated the effects of DAAO inhibitors on d-serine concentration in rats. In the present study, rat DAAO was efficiently expressed in Escherichia coli. The recombinant enzyme was purified as an active, 40 kDa monomeric flavoenzyme showing the basic properties of the dehydrogenase-oxidase class of flavoproteins. Rat DAAO differs significantly from the human counterpart because: (a) it possesses a different substrate specificity; (b) it shows a lower kinetic efficiency, mainly as a result of a low substrate affinity; (c) it differs in affinity for the binding of classical inhibitors; (d) it is a stable monomer in the absence of an active site ligand; and (e) it interacts with the mammalian protein modulator pLG72 yielding a ~100 kDa complex in addition to the ~200 kDa one, as formed by the human DAAO. Furthermore, the concentration of endogenous D-serine in U87 glioblastoma cells was not affected by transfection with rat DAAO, whereas it was significantly decreased when expressing the human homologue. These results raise doubt on the use of the rat as a model system for testing new drugs against schizophrenia and indicate a different physiological function of DAAO in rodents and humans.
 ...
PMID:Is rat an appropriate animal model to study the involvement of D-serine catabolism in schizophrenia? Insights from characterization of D-amino acid oxidase. 2198 Oct 77

Human endogenous retroviruses (HERVs) have been associated with various neurological and neuropsychiatric disorders. Transcripts and proteins of at least three HERV groups, HERV-W, ERV9 and HERV-K(HML-2) have been detected repeatedly in brain samples or cerebrospinal fluid of patients with schizophrenia suggesting that alterations in HERV activity may play a role in etiopathogenesis. Current therapies otherwise include neuroleptics and/or antidepressants that may induce epigenetic alterations and thus influence HERV expression. To investigate the effects of these drugs on HERV transcriptional activity, HERV expression profiles of a broad range of human brain cell lines treated with valproic acid (VPA), haloperidol, risperidone, and clozapine were analyzed using a retrovirus-specific microarray and qRT-PCR. Investigation of 52 HERV subgroups revealed upregulation of several class I and class II HERV elements by VPA in a dose-dependent manner. The strongest effect was observed on HERV-W and ERV9 groups in the human glioblastoma cell lines SK-N-SH and SK-N-MC, respectively. The transcript level of HERV-K(HML-2) elements was not influenced. Transcription of HERV-W, ERV9 and HERV-K(HML-2) taxa was further quantified in postmortem brain samples of patients with schizophrenia, bipolar disorders and a healthy control group with regard to their medication. Patients with schizophrenia showed a significantly higher HERV-W transcription associated with VPA treatment. However in case of ERV9, enhanced transcript levels could not be explained solely by VPA treatment, since a slight increase was also found in untreated patients compared to healthy controls. HERV-K(HML-2) elements appeared to be upregulated in some patients with bipolar disorders independent from medication. In conclusion, these results suggest that antipsychotic medication may contribute to increased expression of distinct HERV taxa in patients with neuropsychiatric diseases.
 ...
PMID:Influence of antipsychotic drugs on human endogenous retrovirus (HERV) transcription in brain cells. 2225 75

Considering the key role of d-serine in N-methyl-d-aspartate receptor-mediated neurotransmission, it is highly relevant to define the role that enzymes play in d-serine synthesis and degradation. In particular, the details of regulation of the d-serine catabolic human enzyme d-amino acid oxidase (hDAAO) are unknown although different lines of evidence have shown it to be involved in schizophrenia susceptibility. Here we investigated the effect of three single nucleotide polymorphisms and known mutations in hDAAO, i.e., D31H, R279A, and G331V. A very low amount of soluble G331V hDAAO is produced in E. coli cells: the recombinant variant enzyme is fully active. Human U87 glioblastoma cells transiently transfected for G331V hDAAO show a low viability, a significant amount of protein aggregates, and augmented apoptosis. The recombinant D31H and R279A hDAAO variants do not show alterations in tertiary and quaternary structures, thermal stability, binding affinity for inhibitors, and the modulator pLG72, whereas the kinetic efficiency and the affinity for d-serine and for FAD were higher than for the wild-type enzyme. While these effects for the substitution at position 31 cannot be structurally explained, the R279A mutation might affect the hDAAO FAD-binding affinity by altering the "structurally ambivalent" peptide V47-L51. In agreement with the observed increased activity, expression of D31H and R279A hDAAO variants in U87 cells produces a higher decrease in cellular d/(d+l) serine ratio than the wild-type counterpart. In vivo, these substitutions could affect cellular d-serine concentration and its release at synapsis and thus might be relevant for schizophrenia susceptibility.
 ...
PMID:Characterization of human DAAO variants potentially related to an increased risk of schizophrenia. 2321 54


1 2 3 Next >>