Gene expression profiling of major depression and suicide in the prefrontal cortex of postmortem brains.

Genome-wide gene expression analysis using DNA microarray has a great advantage to identify the genes or specific molecular cascades involved in mental diseases, including major depression and suicide. In the present study, we conducted DNA microarray analysis of major depression using postmortem prefrontal cortices. The gene expression patterns were compared between the controls and subjects with major depression. As a result, 99 genes were listed as the differentially expressed genes in major depression, of which several genes such as FGFR1, NCAM1, and CAMK2A were of interest. Gene ontology analysis suggested an overrepresentation of genes implicated in the downregulation or inhibition of cell proliferation. The present results may support the hypothesis that major depression is associated with impaired cellular proliferation and plasticity. Comparison between the controls and suicide victims with major depression, bipolar disorder, or schizophrenia was also conducted in the present study. Two genes, CAD and ATP1A3, were differentially expressed in the three comparisons in the same direction. Interestingly, these two genes were also included in the differentially expressed 99 genes in major depression. It may be worth investigating the genes in relation to suicide or major depression.