论文部分内容阅读
The DLC-1 gene,located at the human chromosome region 8p22,behaves like a tumorsuppressor gene and is frequently deleted in diverse tumors.The deletion of 8p22 is not an uncommon eventin nasopharyngeal carcinoma(NPC),therefore we explored the expression levels of the DLC-1 gene in NPCsand NPC cell lines by reverse transcription-polymerase chain reaction.The results showed the mRNA levelof DLC-1 was downregulated.To identify the mechanism of DLC-1 downregulation in NPC,we investigatedthe methylation status of the DLC-1 gene using methylation-specific PCR,and found that 79%(31 of 39)ofthe NPC tissues and two DLC-1 nonexpressing NPC cell lines,6-10B and 5-8F,were methylated in theDLC-1 CpG island.Microsatellite PCR was also carried out,and loss of heterozygosity was found at fourmicrosatellite sites(D8S552,D8S 1754,D8S 1790 and D8S549)covering the whole DLC-1 gene with ratiosof 33%(4 of 12 informative cases),18%(2 of 11),5%(1 of 18),and 25%(3 of 12),respectively.Takentogether,our results suggest that DLC-1 might be an NPC-related tumor suppressor gene affected by aberrantpromoter methylation and gene deletion.
The DLC-1 gene, located at the human chromosome region 8p22, behaves like a tumors suppressor gene and is frequently deleted in depressed tumors. The deletion of 8p22 is not an uncommon event in nasopharyngeal carcinoma (NPC), therefore we explored the expression levels of the DLC-1 gene in NPCs and NPC cell lines by reverse transcription-polymerase chain reaction. The results showed the mRNA level of DLC-1 was downregulated. To identify the mechanism of DLC-1 downregulation in NPC, we investigated the methylation status of the DLC-1 gene using methylation-specific PCR, and found that 79% (31 of 39) of the NPC tissues and two DLC-1 nonexpressing NPC cell lines, 6-10B and 5-8F, were methylated in the DC- 1 CpG island. Microsatellite PCR was also carried out, and loss of heterozygosity was found at four microsatellite sites (D8S552, D8S 1754, D8S 1790 and D8S549) covering the whole DLC-1 gene with ratios of 33% (4 of 12 informative cases), 18% (2 of 11) , 5% (1 of 18), and 25% (3 of 12), respectively suggest that DLC-1 might be an NPC-related tumor suppressor gene affected by aberrant promoter MOT methylation and gene deletion.