Identification of dioxin-responsive genes in Hep G2 cells using differential mRNA display RT-PCR.

Differential mRNA display RT-PCR (DD RT-PCR) offers a tool to identify genes which are regulated or responsive to certain receptors or chemicals such as dioxin (TCDD). Treatment of Hep G2 cells with TCDD followed by DD analysis of a gel with series of different primers revealed a significantly different pattern from the control for a number of mRNAs. The differentially displayed mRNAs were isolated and reamplified. A GenBank search of four mRNAs revealed two known and two unknown sequences. Northern blot analysis revealed that two known sequences, fibrinogen gamma chain and plastin mRNAs were down regulated by TCDD in a time-dependent manner, whereas two unknown mRNAs were induced by TCDD treatment. The function of these genes in TCDD toxicity is not known; however, the application of DD RT-PCR in the studies of TCDD-induced responses could be very useful in the discovery of other unknown genes important for TCDD toxicity.