The pattern of gene expression and possible relation of steroidogenic genes in oligodendroglial tumors.

Steroidogenic acute regulatory protein (StAR) regulates the rate-determining step of steroidogenesis. StAR is expressed at a very low level in the white matter of the normal human brain, but is highly expressed in several brain neoplasms including oligodendroglioma (OD). The aim of this study was to identify the different patterns of gene expression low-grade OD and high-grade OD. We carried out gene expression profiling and analyzed the data. In addition, real-time PCR using StAR primer and immunofluorescent study for StAR were performed. There was a difference in genetic expression between low- and high-grade ODs. An elevated expression of several genes involved in lipid and steroid synthesis, compared with normal white matter, was observed. The expression of such genes showed a tendency either of decreasing or mildly increasing, in high-grade ODs, compared with low-grade ODs. Real-time PCR showed that expression of StAR was relatively low in high-grade ODs, in comparison with low-grade ODs. The pattern of expression between low- and high-grade ODs can differ. This study suggests that the mechanism of neurosteroids synthesis through StAR can be related to the growth of ODs.