Interaction between NFATc2 and the transcription factor Sp1 in pancreatic carcinoma cells PaTu 8988t

Abstract

BackgroundNuclear factors of activated T-cells (NFATs) have been mainly characterized in the context of immune response regulation because, as transcription factors, they have the ability to induce gene transcription. NFAT proteins are found in several types of tumors, for instance, pancreatic carcinoma. The role of NFATs in carcinogenesis is regulating central genes in cell differentiation and cell growth. NFAT proteins are primarily located in cytoplasm and only transported to the cell nucleus after activation. Here, they interact with other transcription factors cooperating with NFAT proteins, thus influencing the selection and regulation of NFAT-controlled genes. To identify and characterize possible interaction partners of the transcription factor NFATc2 in pancreatic carcinoma cells PaTu 8988t.MethodsNFATc2 expression and the mode of action of Ionomycin in the pancreatic tumor cell lines PaTu 8988t were shown with Western blotting and immunofluorescence tests. Potential partner proteins were verified by means of immunoprecipitation and binding partners, their physical interactions with DNA pull-down assays, siRNA technologies, and GST pull-down assays. Functional evidence was complemented by reporter–promoter analyses.ResultsNFATc2 and Sp1 are co-localized in cell nuclei and physically interact at the NFAT target sequence termed NFAT-responsive promotor construct. Sp1 increases the functional activity of its binding partner NFATc2. This interaction is facilitated by Ionomycin in the early stimulation phase (up to 60 min).ConclusionsOncological therapy concepts are becoming more and more specific, aiming at the efficient modulation of specific signal and transcription pathways. The oncogenic transcription partner Sp1 is important for the transcriptional and functional activity of NFATc2 in pancreatic carcinoma. The binding partners interact in cells. Further studies are necessary to identify the underlying mechanisms and establish future therapeutic options for treating this aggressive type of tumor.

Effects of Ketamine, S-Ketamine and MK 801 on Integrin Beta-3-mediated Cell Migration in Pancreatic Carcinoma

“…A key factor in the carcinogenesis of pancreatic carcinoma is the family of NFAT (nuclear factor of activated T-cells) transcription factors [ 15 ]. Preliminary work has shown that NFATc2 interacts with other transcriptional partners, such as the oncogenic protein Sp1 in pancreatic cancer, and that carcinogenic effects are caused by the interaction of NFATc2 and Sp1 [ 16 ]. The application of ketamine or s-ketamine seems to inhibit this activation cascade [ 17 ].…”

The active role of the transcription factor Sp1 in NFATc2-mediated gene regulation in pancreatic cancer

“…Binding partners are a decisive factor in the specificity of transcription factors in cells. Recent investigations have shown the important role of the oncogenic transcription factor Sp1 in the transcriptional activity of NFATc2 in pancreatic cancer [13], in which interaction between binding partners occurs within the cell. However, the role of this interaction in pancreatic cancer is still unclear.…”

“…Chemicals, reagents, equipment an methodology used in the current study were mostly described previously in [13].…”

“…Sp1 is composed of an N-terminus consisting of activating domains that weight about 70 kDa as well as of 3 zinc fingers measuring about 15 kDa that are localized at the C-terminal part. The 3 zinc fingers simultaneously represent the DNA-binding domain [13]. The corresponding complex formation between Sp1 and its binding partners occurs at the intracellular level [14].…”