Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P10415 (Bcl-2)
 33,771 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The abundant expression of progesterone receptors (PR) in human meningiomas is well established. It is unknown, however, how PR expression is regulated, especially since estrogen receptors (ER) are virtually absent in these tumors. At the mRNA level, ER splice variants occur in meningioma but these appear not to be involved in the apparently autonomous PR expression. In an earlier study, because other ER-inducible proteins were either not expressed at all (pS2) or were expressed at a very low level compared to their expression in breast cancer (Cathepsin-D), the authors have postulated that the autonomous PR expression in meningioma is PR promoter-related rather than ER-related and have studied PR expression in cultured meningioma cells. PR levels appeared to decrease rapidly in vitro in monolayer as well as in three dimensional spheroid cultures. Culture conditions thus are not yet sufficient for the quantitative evaluation of PR expression. To evaluate whether PR deterioration is associated with cell turnover (meningiomas grow much faster in vitro than in vivo), the relationship between expression of the apoptotic proteins Bcl-2 and Bax and PR expression was investigated. Bcl-2 expression was found to be highest in meningioma with low PR levels, and in breast cancer tissue with high PR levels. Bax expression was not related to PR expression in any of the two tissues. Given the potential benefit of antiprogestin treatment and the occurrence in meningiomas of a protein capable of binding to the estrogen-responsive element, the expression of PR in meningioma remains a fascinating phenomenon which requires further investigation.
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PMID:Occurrence, regulation, and significance of progesterone receptors in human meningioma. 1110 90

Inherited mutations of the BRCA1 gene predispose to breast, ovarian, and other cancers. The role of the BRCA1 gene in the maintenance of chromosomal integrity is linked to a number of biological properties of its protein product, including transcriptional regulation. In the present study, we have used suppression subtractive hybridisation (SSH) to identify genes induced by BRCA1 by comparing control MCF7 breast carcinoma cells (driver) with MCF7 cells ectopically expressing BRCA1 (tester) and generated a forward subtracted cDNA library. We screened 500 putative positive clones from this library. Two hundred and ten of these clones were positive by differential screening with forward and reverse subtracted probes and the 65 cDNA clones which showed more than fivefold increase were selected for sequencing analysis. We clustered 46 different genes that share high homology with sequences in the GenBank/EMBL databases. Among these, 30 were genes whose function had been previously identified while the remaining 16 clones were genes with unknown functions. Of particular interest, BRCA1 gene induces the expression of genes encoding DNA repair proteins RAD21 and MSH2, ERBB2/HER2 interacting protein ERBIN, meningioma-associated protein MAC30, and a candidate ovarian tumour-suppressor OVCA1. Northern and Western blot analyses confirmed that the expression of these five genes are up-regulated following BRCA1 overexpression in MCF7 and UBR60-bcl2 cells. This is the first study reporting a set of BRCA1-induced genes in breast carcinoma cells by the SSH technique. We suggest that some known genes identified in this study may provide new insights into the tumour-suppressor function of BRCA1.
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PMID:Identification of genes induced by BRCA1 in breast cancer cells. 1247 Jun 55

We report a case of solitary fibrous tumor involving the spinal nerve root at the L1-L2 level in a 67-year-old man. The patient presented with lumbar pain and weakness in his right lower extremity. Histologically, the tumor was composed of a proliferation of monomorphous spindle cells in an abundant collagenous stroma; neither necrosis nor mitoses were evident. These cells were strongly immunoreactive with CD34, Bcl-2, CD99, and vimentin, but were negative with S100 protein, smooth muscle actin, and epithelial membrane antigen. Such an immunohistochemical profile was consistent with a solitary fibrous tumor of the spinal nerve rootlet and ruled out the main differential diagnoses, schwannoma and meningioma. The present case suggests that solitary fibrous tumor should be considered in differentiating spindle cell lesions of the spinal cord and nerve rootlet.
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PMID:Solitary fibrous tumor of the spinal nerve rootlet: report of a case mimicking schwannoma. 1498 50

Two cases of solitary fibrous tumor of the spinal cord are described. The patients were two men, 36 and 47 years old. Clinically, they sought medical care because of progressive paresthesias or urinary incontinence caused by a nodular, fairly circumscribed intraspinal tumor of the cervical and thoracic spinal cord, respectively. Preoperative magnetic resonance images suggested meningioma. In both cases, laminectomy with tumor resection was carried out. Microscopically, the tumors featured short spindle cells haphazardly enmeshed in a collagenized ground substance. No atypia, necrosis, or significant mitotic activity was recognized. Tumor cells were positive for CD34, bcl2, vimentin, and, in one case, CD99. Both patients recovered from symptoms and are alive and well 12 and 18 months, respectively, after surgical resection. The differential diagnosis includes meningioma, schwannoma, and hemangiopericytoma, all of which may occur in the spinal canal. A careful morphologic approach and the judicious use of immunohistochemistry may assist in distinguishing among these conditions, although some irreducible difficulties may be posed by hemangiopericytoma. Although solitary fibrous tumor of the spinal cord presents with fairly comparable clinical, instrumental, and pathologic patterns, we believe that compilation of more cases is needed to segregate it as a distinct clinicopathologic entity.
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PMID:Solitary fibrous tumor of the spinal cord: a clinicopathologic study of two cases. 1549 32

Tumors of the central nervous system account for approximately 9% of all primary neoplasm in humans, while tumors of covering elements, the meninges, account for 13-19% and constitute the second largest group of brain tumors. These are known to exhibit a variety of chromosomal abnormalities besides change in the expression level of certain oncogenes. Among oncogenes, bcl2, an anti-apoptotic factor and ROS1 that encodes a protein with a structure similar to the epidermal growth factor (EGF) and insulin receptor and has a tyrosine kinase activity, have been shown to be associated with many malignant tumors. In the present study we have analysed the expression of bcl2 using immuno-histochemistry and ROS1 expression by reverse-transcription coupled with polymerase chain reaction (RT-PCR) of the transcript using primers specific for the intra-cellular domain and then tried to correlate the findings with the subtype of the meningioma defined on the basis of histology. Out of the six bcl2 positive cases in our study, there were three transitional tumors, two fibroblastic and one recurrent meningioma subtype. bcl2 seemed to be more consistently expressed in the cytoplasm of spindle cell component of meningiomas. Thirteen meningiothelial meningiomas did not show any staining for bcl2. ROS1 gene expression could be detected in 4 tumors all of those were Grade-I meningothelial meningiomas. One of the malignant meningioma included in the study was clearly negative for bcl2 as well as ROS1. Thus bcl2 and ROS1 oncogene expression in meningiomas are not concurrent and neither can be ascribed to any histologic subtype or grade of tumor.
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PMID:Bcl2 and ROS1 expression in human meningiomas: an analysis with respect to histological subtype. 1676 43

Although most meningiomas are treated surgically, it may not be possible to completely remove atypical, malignant, and surgically inaccessible meningiomas; in the majority of these cases there is tumor recurrence. The authors have already reported initial preclinical results on the efficacy of imatinib in the treatment of meningiomas; however, a recent Phase II trial of imatinib in patients with recurrent meningiomas did not demonstrate significant antitumor activity. To enhance the activity of imatinib, the authors investigated the use of a combination therapy with nelfinavir on primary meningioma cells and meningioma cell lines IOMM-Lee and CH157. Cytotoxicity was measured using methylthiotetrazole and colony formation assays. In low-dose combination therapy with imatinib, nelfinavir potentiated the antiproliferative and anti-colony formation effects of imatinib. Primary meningioma cells responded better to combination therapy than to imatinib alone. Treatment induced a dose-dependent antiproliferative effect, decreased cell survival, and inhibited colony formation. Western blotting demonstrated decreased levels of survivin protein on combination therapy. Because meningiomas have very high levels of survivin protein, survivin inhibition by nelfinavir may represent a potential mechanism for the additive effect observed with imatinib. Moreover, an increase in the proapoptotic Bax/Bcl-2 protein ratio was demonstrated with the combination of imatinib and nelfinavir. The authors propose that nelfinavir not only potentiates imatinib efficacy, it also abrogates resistance to imatinib by decreasing survivin protein levels in meningiomas. In an in vivo assay, this combination therapy was found to be more effective than imatinib alone. More preclinical work with in vivo models is needed to determine if this new combination therapy will translate into a viable future therapy for meningiomas.
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PMID:Nelfinavir potentiation of imatinib cytotoxicity in meningioma cells via survivin inhibition. 1796 Oct 46

Meningiomas are well known to be responsive to estrogen/progesterone stimulation, and their expression of estrogen/progesterone receptor (ER/PR) has been documented. On the other hand, there are several reports studying expression of apoptosis-regulating proteins (ARPs) and its significance in meningiomas. However, very limited published information exists on the exact relation among sex hormone receptor status, apoptosis, proliferation index (PI), and histological grade in meningiomas. A total of 57 cases of non-malignant meningiomas were selected, and histologically reviewed and graded (WHO grades 1, 2). All these cases were immunostained for ER, PR, Ki-67, and ARPs including bax, bcl-2, and bcl-xL. Sections were graded semiquantitatively for intensity and extent of immunostaining. PI was expressed as a percentage of Ki-67 positive tumor cells. Expression of bax, bcl-2, bcl-xL, ER, and PR was seen in 100, 35.1, 24.6, 10.4, and 87.2% of cases, respectively. Bax was expressed diffusely and strongly, while Bcl-2 tended to be expressed weakly and focally. Bcl-xL appeared to be expressed relatively strongly and diffusely in a small subset. There was significantly higher PI as well as expression of PR in grade 1 group than in grade 2 group. A weak negative correlation was observed between Bcl-2 and PR (r =-0.472, P < 0.0014). Given high-level expression of pro-apoptotic bax, which seems to be constitutionally expressed, in contrast to low-level expression of antiapoptotic bcl-2 and bcl-xL, other antiapoptotic proteins may involve the proliferation of meningiomas. A significant negative relation exists between PR and Bcl-2 in meningiomas, which might have some biological and clinical significance.
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PMID:Immunohistochemical expression of apoptosis regulating proteins and sex hormone receptors in meningiomas. 1802 Nov 95

Although meningiomas represent the most common class of tumors of the central nervous system, the molecular events underlying their genesis and development are still not well defined, and therapeutic approaches based on the genetics of these tumors are currently lacking. In the present study we have used the immunoblotting technique to show that the p16(INK4A), Cdk6 and pRB proteins are differentially expressed in primary meningioma cells with 20-, 30- and 36-fold difference between the lowest and the highest levels of each protein, respectively. In addition, we present evidence that the level of the anti-apoptosis survivin protein is high in these benign tumors. Moreover, the annexin V-associated flow cytometry technique was used to show that 60% of meningioma cell cultures underwent apoptosis in response to both gamma-rays and cisplatin, and 50% of these cells exhibited significant sensitivity to hydroxyurea. These agents triggered apoptosis through the mitochondrial pathway, by increasing the Bax/Bcl-2 ratio. Interestingly, the induction of apoptosis following radiation and cisplatin was significant in all cells that expressed low levels of p16(INK4A), Cdk6 and pRB proteins. These data shed more light on the molecular biology of meningioma cells and suggest that survivin and proteins of the RB pathway could play a determinant role in the development and the treatment of meningiomas.
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PMID:Expression of survivin and p16(INK4a)/Cdk6/pRB proteins and induction of apoptosis in response to radiation and cisplatin in meningioma cells. 1804 12

We report a case of malignant solitary fibrous tumor involving the pineal region in a 49-year-old woman. The patient presented with headache, slowly progressive weakness of the right lower extremities and upgaze palsy over the past year. Histologically, the tumor was composed of moderately hypercellular proliferated spindle cells with eosinophilic collagen bands. These cells were diffusely and strongly immunoreactive with CD34, CD99, and vimentin, but were negative with epithelial membrane antigen, S-100 protein, Bcl-2, smooth muscle actin, cytokeratin and glial fibrillary antigenic protein. MIB-1 labeling indices and mitosis rates were 7.3 +/- 1.8% and 5 per 10 high power fields, respectively. Ultrastructural examination revealed that the neoplastic cells had features of fibroblastic differentiation. Differential diagnoses included fibrous meningioma and hemangiopericytoma. The present case provides one unique example of a rare entity to the already diverse spectrum of the pineal region neoplasms encountered in neuropathology.
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PMID:Malignant solitary fibrous tumor arising from the pineal region: case study and literature review. 1984 65

Meningiomas are the most commonly occurring intracranial tumors and account for approximately 15-20% of central nervous system tumors. Patients whose tumors recur after surgery and radiation therapy have limited therapeutic options. It has also been reported recently that radiation triggers DNA repair, cell survival and cell proliferation, and reduces apoptosis via the induction of cellular protective mechanisms. Earlier studies have reported that proteases such as uPA, uPAR and cathepsin B play important roles in tumor progression. In the present study, we attempted to determine the effectiveness of two bicistronic siRNA constructs pUC (uPAR/cathepsin B) and pU2 (uPA/uPAR) either alone or in combination with radiation, both in in vitro and in vivo models. Transfection of a plasmid vector expressing double-stranded RNA for uPA, uPAR and cathepsin B significantly induced the sub-G0-G1 cell population by the mitochondrial intrinsic apoptotic pathway. Results showed that pUC efficiently enhanced sub-G0-G1 phases compared to pU2 and was more effective. Interestingly, we observed that in IOMM-Lee cell lines, combined treatment of radiation with pUC and pU2 is more effective in comparison to SF-3061 and MN cell lines. We showed that apoptosis caused by these bicistronic constructs involves Bcl-2, Bcl-xL, p53 inactivation, cytochrome c release from mitochondria and caspase-9 activation, followed by the activation of caspase-3. We also determined that apoptosis caused by pUC and pU2 involves a mechanism which includes inactivation of p53 by its translocation from nucleus to cytoplasm as confirmed by immunofluorescence, which shows the oncogenic potential of p53 in meningiomas. However, the simultaneous RNAi-mediated targeting of uPAR and cathepsin B (pUC), in combination with irradiation, has greater potential application for the treatment of human meningioma in comparison to pU2 by decreasing p53 expression both in vitro and in vivo.
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PMID:Oncogenic role of p53 is suppressed by si-RNA bicistronic construct of uPA, uPAR and cathepsin-B in meningiomas both in vitro and in vivo. 2129 90


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