| Abstract | Recent advances have facilitated the use of blood-derived RNA to conduct genomic analyses of human diseases. This emerging technology represents a rigorous and convenient alternative to traditional tissue biopsy-derived RNA, as it allows for larger sample sizes, better standardization of technical procedures, and the ability to non-invasively profile human subjects. In the present pilot study, we have collected RNA from blood of patients diagnosed with schizophrenia or bipolar disorder (BPD), as well as normal control subjects. Using microarray analysis, we found that each disease state exhibited a unique expressed genome signature, allowing us to discriminate between the schizophrenia, BPD, and control groups. In addition, we validated changes in several potential biomarker genes for schizophrenia and BPD by RT-PCR, and some of these were found to code to chromosomal loci previously linked to schizophrenia. Linear and non-linear combinations of eight putative biomarker genes (APOBEC3B, ADSS, ATM, CLC, CTBP1, DATF1, CXCL1, and S100A9) were able to discriminate between schizophrenia, BPD, and control samples, with an overall accuracy of 95%-97% as indicated by receiver operating characteristic (ROC) curve analysis. We therefore propose that blood cell-derived RNA may have significant value for performing diagnostic functions and identifying disease biomarkers in schizophrenia and BPD. |
| Abstract | Recent studies reported gene expression alterations in peripheral blood cells (PBC) obtained from patients with schizophrenia as compared to healthy controls. These alterations can not only be regarded as potential biomarkers but can also further our understanding of the disease. In light of previous reports, expression levels of the following genes: APOBEC3B, CXCL1, DRD2, GNAO1, Kir2.3, S100A9, and SELENBP1 in PBCs were compared between 30 first-hospitalized patients with schizophrenia and 26 healthy controls using quantitative real-time PCR. A significant elevation (2.6-fold; p<0.05) was confirmed for transcripts from the gene CXCL1 but not from the other genes investigated. Within the patients group, APOBEC3B expression was inversely correlated with duration of neuroleptic treatment. These findings indicate that gene expression in PBC from patients with schizophrenia may not only vary with the methods used for analysis but also with state-related differences in gene expression. |