Microsatellite mapping of chromosome 13q33-34 region, mutation screening of ING1 gene and analysis of ING1 mRNA expression in bladder cancers

In Turkey, the frequency of bladder cancer is the third among other cancer types. Cancer is a result of the accumulation of genetic and epigenetic alterations in the cell which can lead to activation of oncogenes or inactivation of tumor suppressor genes (TSG). Loss or inactivation of TSGs can lead formation of tumors. Members of ING family are discovered as TSGs in different cancer types. In this study 30 paired normal and tumor tissue samples were used for microdeletion analysis of chromosome 13q33-34 region, ING1 expression analysis and ING1 mutation screening via nucleotide sequence analysis. Because there is no data available about the transcription factors which bind to ING1 promoter, the promoter sequence was analyzed via Genomatix-MatInspector and TFSEARCH programs. DS markers used for 13q33-34 region were D13S285, D13S1315, D13S796, D13S278, D13S158, and D13S779 where loss of heterozygosity (LOH) results were as 66.7%, 20%, 6.7%, 3.3%, 6.7%, and 0%, respectively. The highest LOH scores were obtained with markers D13S285 and D13S1315 which were flanking the ING1 gene. Seven of 30 cases showed alterations in expression analysis. However, no mutation was detected in the exons of ING1. A significant TSG activity of ING1 in bladder cancer was not observed while higher activity was reported in different cancer types. As for the LOH data 13q33-34 region may contain different candidate TSGs like COL4A1, COL4A2 and SOX1. As a result of promoter analysis, some factors like c-Rel, c-Ets were associated with the promoter region. Molecular analysis of ING1 promoter warrants further analysis.