Use of an array technology for profiling and comparing transcription factors activated by TNFalpha and PMA in HeLa cells.

Multiple signal transduction pathways are generally triggered simultaneously by a single extracellular stimulus. As a result, multiple transcription factors (TFs) can be activated downstream to mediate the inducible expression of target genes. Profiling the activation of all TFs will aid in the dissection of the numerous pathways of signal transduction. Tumor necrosis factor alpha (TNFalpha) and phorbol 12-myristate 13-acetate (PMA) mediate many biological functions, including cell proliferation and apoptosis, by stimulating signaling pathways. Two TFs, nuclear factor kappaB (NFkappaB) and activating factor 1 (AP1), have been identified as targets of both TNFalpha and PMA activation. Here, we describe the use of a protein/DNA array system to identify additional TFs activated by TNFalpha and PMA in HeLa cells. From a total of 150 targeted TFs, six-CREB, E2F, CETP/CRE, c-Rel, MSP1, and Pax6-were identified whose activities, like NFkappaB and AP1, were regulated by both TNFalpha- and PMA-induced pathways. Interestingly, the TF E47 was shown to be specifically activated by TNFalpha but was not affected by treatment with PMA. In addition, GATA, NF-E1, and ISRE were shown to be specifically activated by PMA but not TNFalpha. These findings suggest that TNFalpha and PMA both stimulate unique signaling pathways while mediating transcriptional activation through common pathways.