GSK-3β Governs Inflammation-Induced NFATc2 Signaling Hubs to Promote Pancreatic Cancer Progression

Abstract

We aimed to investigate the mechanistic, functional and therapeutic role of GSK-3β in the regulation and activation of the pro-inflammatory oncogenic transcription factor NFATc2 in pancreatic cancer. Immunohistochemistry, quantitative real-time polymerase chain reaction, immunoblotting, immunofluorescence microscopy and proliferation assays were used to analyze mouse and human tissues and cell lines. Protein-protein interactions and promoter regulation were analyzed by co-immunoprecipitation, DNA pull-down, reporter, and ChIP assays. Preclinical assays were performed using a variety of pancreatic cancer cells lines, xenografts and a genetically engineered mouse model (GEMM). GSK-3β-dependent SP2 phosphorylation mediates NFATc2 protein stability in the nucleus of pancreatic cancer cells stimulating pancreatic cancer growth. In addition to protein stabilization, GSK-3β also maintains NFATc2 activation through a distinct mechanism involving stabilization of NFATc2-STAT3 complexes independent of SP2 phosphorylation. For NFATc2-STAT3 complex formation, GSK-3β-mediated phosphorylation of STAT3 at Y705 is required to stimulate euchromatin formation of NFAT target promoters such as cyclin dependent kinase −6 (CDK-6), which promotes tumor growth. Finally, preclinical experiments suggest that targeting the NFATc2-STAT3-GSK-3β module inhibits proliferation, tumor growth, and interferes with inflammation-induced pancreatic cancer progression in KrasG12D mice. In conclusion, we describe a novel mechanism by which GSK-3β fine-tunes NFATc2 and STAT3 transcriptional networks to integrate upstream signaling events that govern pancreatic cancer progression and growth. Furthermore, the therapeutic potential of GSK-3β is demonstrated for the first time in a relevant Kras and inflammation-induced GEMM for pancreatic cancer.

Identification of chromatin‐accessible domains in non‐alcoholic steatohepatitis‐derived hepatocellular carcinoma

“…This suggestion is supported by evidence showing an increased level of histone H3K27ac in HCC. 55 Additionally, a critical role of NFATC1 and NFATC2 transcription factors in cancer development, 56,57 including HCC, 58 has been reported.…”

Cell cycle and apoptosis regulation by NFAT transcription factors: new roles for an old player

“… 77 The same group has also demonstrated NFAT1 cooperating with STAT3 to promote CDK6 upregulation and pancreatic cancer cell proliferation. 46 Remarkably, loss of STAT3 expression reversed the NFAT1-dependent stimulation of proliferation, emphasizing how the signaling pathways present when NFAT is activated might convert NFAT from activators to repressors or vice versa . 46 …”

“…NFAT proteins can interact with several transcription factors and regulators in the nucleus, being important integrators of calcium signals with other signaling pathways. 15 , 28 The interaction of NFAT with other proteins through their conserved DBD and NHR regions can result in synergistic activation 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 (such as with GATA-3; 38 ICSBP; 42 C/EBP; 43 AP-1 41 , 44 ) or repression 47 , 48 , 49 , 50 , 51 , 52 , 53 (PPARγ 47 , 48 Mrj; 49 Foxp3; 50 , 51 ICER 52 ) of NFAT-mediated transcription ( Table 1 ). Although the interactions with DBD and NHR regions are important for NFAT function, in this section, we will focus on the NFAT partners that interact with the less conserved NFAT TAD regions.…”

GSK-3Beta-Dependent Activation of GEF-H1/ROCK Signaling Promotes LPS-Induced Lung Vascular Endothelial Barrier Dysfunction and Acute Lung Injury

“…In addition, these results identify a critical function for GSK-3beta in modulating micro-vascular barrier disruption-associated ALI in vivo in mice and provide a rationale for regulating the lung edema under septic condition. However, even though our study and other studies (Baumgart et al, 2016 ; Liu et al, 2016 ) find that there are various conditions in which the possible involvement of GSK-3beta has been implied (pro-inflammation, hyper-coagulation and hyper-permeability), the efficacy of GSK-3beta inhibitor in inhibiting sepsis-associated ALI in humans has not yet been examined successfully, and further investigations are necessary.…”