JOURNAL OF NEUROLOGICAL SCIENCES-TURKISH, cilt.28, ss.563-580, 2011 (SCI İndekslerine Giren Dergi)
The aim of the study is to the determine the profiles of tumor suppressor genes and oncogenes which cause brain tumor, establishing the association between the prognosis of cancer and the quantitation of genetic and epigenetic changes, and bringing a molecular approach to definite diagnosis. For this purpose, explant cell cultures are performed from the anaplastic brain tumor tissues of the cases. The expression analysis of the tumor suppressor genes (p53, RB1, PTEN, MGMT, RUNX3, DMBT1, PIKE) and oncogenes (EGFR, PIK3CA, MDM2, Olig2, GSTT1, COX-2 and hTERT) were determined by comparing the expression of GAPDH housekeeping gene using real-time online RT-PCR. The promoter regions of all the tumor suppressor genes' hypermethylation and also methylated and unmethylated copy numbers were determined with Q-PCR by using methylation specific primer and probes and the quantitation was carried out by comparing with each other. A significant difference was determined among the oncogenes; EGFR and hTERT gene expressions in patient tumor group. hTERT gene expression showed a significant difference with tumor grades. DMBT1 gene expression showed a significant difference with tumor grades. A prominent decrease was found in the aberration of tumor suppressor gene copy number in the glioma group. Gene copy number and gene expression of GSTT1 gene showed a significant correlation. RB1 and MGMT promoter methylation showed a significant difference in tumor patient group. Over expression of PIK3CA, EGFR and COX-2 among oncogenes and loss of copy number of PTEN, RB1 and RUNX3 among tumor suppressor genes found associated with short survival.