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Gamma-hydroxybutyric acid (GHB) acts as an agonist of the GABA B receptor, where GHB induces a depressant effect in the central nervous system. Besides its therapeutic application, GHB is also used as a date rape drug. However, the detection of GHB ingestion proves to be difficult due to its narrow detection window. The aim of this pilot study was to assess differential gene expressions after GHB intake to identify potential biomarkers for the detection of GHB intake. To this aim, alteration in gene expression of ALDH5A1, AKR7A2, EREG, and PEA15 was investigated via quantitative PCR (qPCR). Data normalization was based on a previously established and empirically derived normalization strategy. Blood samples of patients (n = 3) therapeutically taking sodium oxybate solution (GHB) and of donors without GHB intake (n = 49) were analyzed and compared. All qPCR procedures and results are reported according to the MIQE guidelines. Investigation of suitable reference genes using established algorithms suggested PPIB and FPGS as best-suited normalizers. Alterations in gene expression relating to GHB intake could not be confirmed to a forensically sufficient degree. However, significant differences in expression of EREG in the control group were observed, when time-point of sample collection was considered, indicating circadian rhythm. The study's main limitation is the small number of study subjects. Herein, we are first to present an empirically derived strategy for a robust normalization of qPCR data from the analysis of GHB-induced gene expression in human blood. We present results of the analysis of differential expression of ALDH5A1, AKR7A2, EREG, and PEA15 in the GHB-negative population. Finally, we report our findings on the effect of GHB intake on the expression of these genes and their presumable potential as GHB biomarkers.

Purpose: Lynch syndrome (LS) is a common inherited predisposition to colorectal cancer (CRC). In LS patients, CRC is predominantly located in the right colon, as opposed to sporadic CRC, which usually affects the left colon or rectum. Previous studies have demonstrated a clear distinction in gene expression between sporadic CRC and normal colon at different locations in the colorectum. However, little is known about LS gene expression profiles in different areas of the colorectum. Here, we compared the protein expression profiles for normal colorectal samples among different locations as well as between adenomas and matched normal tissue in LS. Methods: Protein from 33 tissue samples (27 normal tissues and 6 adenomas) from 9 patients with LS was extracted for reverse-phase protein array (RPPA) analysis. The antibody panel used for RPPA included 109 key proteins involved in various cancer-related pathways. Cluster 3.0 was used for unsupervised and supervised clustering analysis. Results: IGF1R and COL6A1 were expressed significantly differently between the normal right and normal left colon ( q < 0.05); FN1, COL6A1, and IGF1R were expressed significantly differently between the normal right colon and normal rectum ( q < 0.05). In the adenomas and matched normal tissue, PEA-15 was the only protein with significantly different expression ( q < 0.05). Conclusion: We found differences in protein expression between normal tissues from the right colon, left colon, and rectum as well as between adenomas and matched normal tissue. However, those differences should be further confirmed in a larger sample size. [ABSTRACT FROM AUTHOR]