ABSTRACT
Objective To explore the characteristics of the gene expression in Cushing′s adrenal corticoadenoma and its associated molecular mechanism. Methods cDNA libraries of human normal adrenal and the adenoma were constructed. Large scale sequencing and bioinformatics were used. Results From the tumor library, 2089 expressed sequence tags (ESTs) were obtained with a successful rate of 98.9%. The functional distribution of the known genes in the tumor coincided with that in normal adrenal. Some synthases such as 3bHSDⅡ and P450c17A involved in steroidogenesis were expressed more highly in the adenoma than those in normal adrenal, especially 3bHSDⅡ. By comparison with the expression abundance of genes and statistic analysis, the differences were significant in 45 genes between the tumor and normal adrenal libraries. Interestingly, some genes associated with tumorigenesis, including heat shock protein 90, metallopanstimulin (MPS1), adenine nucleotide translocators etc, were highly expressed in the adenoma. However, those genes related to apoptosis and suppressing proliferation were not found in the tumor library. Conclusion The adenoma shows exuberant activities in steroid synthesis. Not only does the tumor highly express the genes associated with tumorigenesis, but also those related to apoptosis and suppressing proliferation lowly existed in the tumor.