To study the change of gene expression in the brain tissues of
schizophrenia, we used the gene expression monitoring technology and compared two sets of pools each containing four
RNA samples of frontal cortex that were randomly selected from the control or
schizophrenia group. We found that the expression of two genes were commonly altered in four pairwise comparisons; the expression of DEAD-box
protein p72 (p72) gene was increased and
neuropeptide Y (NPY) gene expression was decreased in the
schizophrenia group compared with the control group. To substantiate these results, we estimated their
mRNA levels by the real time TaqMan method in the 15 samples of each frontal or temporal cortex of four matched groups of
schizophrenia,
bipolar disorder, major depression and normal controls. A statistically significant decrease was observed for NPY in the frontal, but not in the temporal cortex, in the
schizophrenia group (P=0.003). A decrease was also observed in the frontal cortex of the
bipolar disorder group (P=0.031). In contrast, p72 gene expression showed no significant difference among the four groups. In conclusion, by novel technology of
DNA array and TaqMan PCR analyses, we found that
neuropeptide Y mRNA levels were significantly reduced in the frontal cortex in both
schizophrenia and
bipolar disorder.