Coexpression of genes involved in apoptosis in central nervous system neoplasms.
OBJECTIVE
Apoptosis plays a crucial role in normal development and mediates tumor response to chemotherapy. This study investigated the pattern of apoptotic gene expression in brain tumor tissue specimens and cell lines.


METHODS
BCL2, BCLXL, BCLXS, and BAX transcripts were amplified using reverse transcriptase polymerase chain reaction in 7 high-grade gliomas (HGGs), 7 ependymomas, and 6 cell lines (2 glioblastomas, 3 medulloblastomas, and 1 supratentorial-primitive neuroectodermal tumor [PNET]). Immunohistochemical staining for BCL2, BCLX, BAX, and p53 was performed in 7 pediatric low-grade gliomas (LGGs) and 7 pediatric HGGs.


RESULTS
Six of seven gliomas, all ependymomas, and all glioblastoma and medulloblastoma cell lines expressed BCLXL and BAX. BCL2 expression was only detected in the supratentorial PNET line PFSK. BCLXS was absent in all tumors. By immunohistochemistry, no glial tumors stained positively for BCL2. Similar BAX and BCLX protein expression was observed in LGG and HGG. Three of five glioblastomas showed significant p53 expression.


CONCLUSIONS
Coexpression of proapoptotic and antiapoptotic genes in human brain tumors supports the hypothesis that the relative expression of competing genes determines apoptotic threshold.
Department of Pediatrics, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, USA.
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Bruggers
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Perkins
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Carroll
D017209:Apoptosis / Q000235:genetics*; D001932:Brain Neoplasms / Q000737:chemistry* / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D015972:Gene Expression Regulation, Neoplastic; D005910:Glioma / Q000737:chemistry* / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D016133:Polymerase Chain Reaction; D011518:Proto-Oncogene Proteins / Q000032:analysis; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis*; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000032:analysis; D051028:bcl-2-Associated X Protein
C494826:BAX protein, human; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53; D051028:bcl-2-Associated X Protein