Analysis of triptolide-regulated gene expression in Jurkat cells by complementary DNA microarray.

Aim: To investigate the global gene expression profile changes in Jurkat cells after triptolide treatment in order to find the possible triptolide targets.

Methods: Jurkat cells were treated with or without triptolide 10 microg/L for 2 h. Total RNA were isolated and used as templates for reverse transcriptional labeling of fluorescent cDNA probes. High density DNA microarray chips with a set of 13,872 human genes/Ests were used to generate the expression profile of triptolide-treated or untreated control Jurkat cells by hybridizing with fluorescent labeled probes. Array image was acquired and analyzed with array analyzing software GeneSpring.

Results: Triptolide significantly suppressed expression of 117 genes in Jurkat cells. Among these 117 genes, 30 % were Ests or genes without known functions, 13 % were transcription factors, 9 % were signal transduction pathway regulators, and 9 % were DNA binding proteins. Notably, the expression of mitogen-activated protein kinase kinase kinase kinase 5 (MAP kinase 5) and phosphoinositide-3-kinase (PI-3 kinase) was inhibited more than 100-fold. Moreover, the expression of genes involved in lipid transportation and metabolism was down-regulated by triptolide.

Conclusion: High-density microarray provided an effective approach to identify drug targeting molecules. It is suggested that the widely known immune suppressive and antitumor effects of triptolide were mediated at least in part by suppression of MAP kinase and PI-3 kinase gene expression.