NFAT Transcription Factors as Therapeutic Targets in Pancreatic Cancer

尽管科学家们做出了巨大的努力来了解胰腺癌的分子生物学， 传统的治疗方法对疾病的进程几乎没有影响。因此，研究 确定胰腺癌和胰腺癌干细胞（CSC）中的关键决定因素， PDAC侵袭性的生物标志物和克服化学抗性的潜在最佳靶标。我们有 发现NFATc 1和NFATc 2（NFATc 1/c2）分别在PDAC样品中异位表达， 针对NFATc 1/c2的药理学抑制或RNAi在体外和体内降低PDAC细胞生长。 有趣的是，我们发现在发育中的小鼠胰腺中组成型核NFATc 1的表达， 使用p48-cre沿着KRasG 12 D，在16-20周龄时发展为侵袭性PDAC，从而证明 NFATc 1是这种疾病中的一个强致癌基因。我们进行了NFATc 1 ChIP-seq，以了解 进入由致癌/炎症转录因子驱动的转录网络。我们确定 近1800个NFATc 1靶基因，其中三分之二依赖于与STAT 3的相互作用。 值得注意的是，大多数NFAT/STAT 3调控的基因网络参与炎症、增殖、炎症反应和炎症反应。 和转移。此外，我们首次证明NFATc 1在胰腺CSC中富集， 从PDAC细胞系和CSC的自我更新产生的抑制剂靶向NFAT 通过使用环孢菌素A（CsA）的核活性。然而，NFAT的机制 调节CSC自我更新和/或化学抗性的机制尚不清楚。此外，我们发现PDAC细胞系， 表达NFATc 1/c2的细胞对CsA敏感，并在体外与吉西他滨协同杀伤肿瘤细胞， 限制体内肿瘤生长。尽管有这些初步观察结果，关于NFATc 1/c2靶点的信息 人PDAC基因缺失及NFATc 1/c2调控胰腺癌细胞的机制 增长仍有待确定。此外，还不清楚NFATc 1/c2的异位表达是否 与疾病的特定临床特征相关，参与胰腺CSC生物学，或代表 临床上的治疗目标。这些悬而未决的问题将在本申请中得到解决。

Despite tremendous scientific efforts aimed at understanding the molecular biology of pancreatic cancer, conventional treatment approaches have had little impact on the course of the disease. Thus, studies identifying key determinants in pancreatic cancer and pancreatic cancer stem cell (CSCs) can provide both biomarkers of PDAC aggressiveness and potentially optimal targets to overcome chemoresistance. We have found that NFATc1 and NFATc2 (NFATc1/c2) are ectopically expressed in PDAC samples, respectively and that pharmacologic inhibition or RNAi toward NFATc1/c2 reduces PDAC cell growth in vitro and in vivo. Interestingly, we show that expression of a constitutive nuclear NFATc1 in the developing mouse pancreas using p48-cre along with KRasG12D develop invasive PDAC by 16-20 weeks of age, thus demonstrating that NFATc1 is a potent oncogene in this disease. We performed NFATc1 ChIP-seq in order to gain insight into the transcriptional network driven by this oncogenic/inflammatory transcription factor. We identified nearly 1800 NFATc1-target genes, two-thirds of which are dependent on an interaction with STAT3. Significantly, most of the NFAT/STAT3-regulated gene networks are involved in inflammation, proliferation and metastasis. Moreover, we demonstrate for the first time that NFATc1 is enriched in pancreatic CSCs generated from PDAC cell lines and CSC self-renewal is inhibited by pharmacologically targeting NFAT nuclear activity through the use of cyclosporine A (CsA). However, the mechanisms by which NFATs regulate CSC self-renewal and or chemoresistance are unclear. Furthermore, we show that PDAC cell lines, which express NFATc1/c2 are sensitive to CsA and synergize with gemcitabine to kill tumor cells in vitro and limit tumor growth in vivo. Despite these preliminary observations, information regarding NFATc1/c2 target genes in human PDAC is lacking and mechanisms by which NFATc1/c2 regulate pancreatic cancer cell growth remain to be determined. Furthermore it is unknown whether ectopic expression of NFATc1/c2 correlates with specific clinical features of the disease, participates in pancreatic CSC biology, or represents a therapeutic target in the clinic. These outstanding questions will be addressed in this application.