Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0017638 (glioma)
 30,880 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The aim of this study is to investigate the effect of the p21 gene transfection on the growth of cultured human glioma cell lines, and analyze the telomerase activity, and detection of telomerase components in p21 transfectant. The p21 gene was transfected into human glioma cell lines, U251MG and T98G with our novel liposome. The cell growth was assessed by counting the number of trypan blue-excluding cells in a hemocytometer and flow cytometry analysis. The expression of P21 protein and its mRNA were examined by Western and Northern blot analysis. The telomerase activity was assayed by TRAP (telomerase repeat amplification protocol)/TRAP-HPA (hybridization protection assay) method qualitatively and quantitatively. The length of telomere was measured by Southern blot analysis. The expression of telomerase components (hTERT, hTERC and TEP1) were examined by RT-PCR (reverse transcriptase-polymerase chain reaction). The p21 transfectant demonstrated the expression of P21 protein and its mRNA. The p21 transfection of human glioma cells results in growth inhibition and G0/G1 arrest. The p21 transfectant revealed a decrease of telomerase activity and hTERT expression as compared with control cells. These results suggest that p21 transfection induces G0/G1 arrest in human glioma cells which associates with the reduction in the telomerase activity and hTERT expression.
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PMID:Growth inhibition of human glioma cells by transfection-induced P21 and its effects on telomerase activity. 1093 98

Parathyroid hormone-related protein (PTHrP) is the major mediator of the humoral hypercalcemia of malignancy and of malignant osteolysis associated with skeletal metastases of common epithelial cancers. PTHrP secretion is regulated by the extracellular calcium concentration ([Ca(2+)](o)) in several types of normal and malignant cells. Because the [Ca(2+)](o)-sensing receptor (CaR) is a key mediator of [Ca(2+)](o)-regulated hormone secretion [e.g., of parathyroid hormone (PTH) by parathyroid chief cells], we investigated the expression of the CaR and PTHrP in normal and neoplastic glial cells and studied the effects of [Ca(2+)](o) on PTHrP secretion. Our results show that primary embryonic human astrocytes (HPA) express CaR mRNA and protein as detected by RT-PCR and Western analysis, respectively. Furthermore, astrocytomas and meningiomas also express the CaR at similar levels as assessed by RT-PCR and Northern and Western blot analyses. HPA and astrocytomas express transcripts encoding all three known isoforms of PTHrP [PTHrP(139), PTHrP(141), and PTHrP(173), comprising 139, 141, and 173 predicted amino acid residues, respectively] as assessed by RT-PCR, whereas meningiomas express only the first two of these. Finally, elevated levels of [Ca(2+)](o) and other polycationic CaR agonists dose dependently stimulate PTHrP secretion from HPA, astrocytomas, and meningiomas, although both basal and high [Ca(2+)](o)-stimulated rates of PTHrP secretion are approximately 2. 5-fold higher in HPA than in the glial tumors studied here. Therefore, our results show that HPA, astrocytomas, and meningiomas express both the CaR and PTHrP and that CaR agonists stimulate PTHrP secretion.
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PMID:Regulation of secretion of PTHrP by Ca(2+)-sensing receptor in human astrocytes, astrocytomas, and meningiomas. 1094 19

Diffuse gliomas are the most common type of primary brain and central nervous system (CNS) tumors. Protein disulfide isomerases (PDIs) such as P4HB and PDIA3 act as molecular chaperones for reconstructing misfolded proteins, and are involved in endoplasmic reticulum stress and the unfolded protein response. The present study focused on the role of P4HB and PDIA3 in diffuse gliomas. Analysis of GEO and HPA data revealed that the expression levels of P4HB and PDIA3 were upregulated in glioma datasets. their increased expression was then validated in 99 glioma specimens compared with 11 non-tumor tissues. High expression of P4HB and PDIA3 was significantly correlated with high Ki-67 and a high frequency of the TP53 mutation. Kaplan-Meier survival curve and Cox regression analyses showed that glioma patients with high P4HB and PDIA3 expression had a poor survival outcome, P4HB and PDIA3 could be independent prognostic biomarkers for diffuse gliomas. In vitro, knockdown of PDIA3 suppressed cell proliferation, induced cell apoptosis, and decreased the migration of glioma cells. Furthermore, downregulation of P4HB and PDIA3 may contribute to improve the survival of patients who receive chemotherapy and radiotherapy. The data suggest that high expression of P4HB and PDIA3 plays an important role in glioma progression, and could predict the survival outcome and therapeutic response of glioma patients. Therefore, protein disulfide isomerases may be explored as prognostic biomarkers and therapeutic targets for diffuse gliomas.
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PMID:P4HB and PDIA3 are associated with tumor progression and therapeutic outcome of diffuse gliomas. 2920 76