Phosphorylation of NFAT3 by CDK3 induces cell transformation and promotes tumor growth in skin cancer.
Phosphorylation of NFAT3 by CDK3 induces cell transformation and promotes tumor growth in skin cancer.
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CDK3 磷酸化 NFAT3 可诱导细胞转化并促进皮肤癌中的肿瘤生长。
DOI：
10.1038/onc.2016.434
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发表时间：
2017-05-18
期刊：
影响因子：
8
通讯作者：
Zheng D
中科院分区：
文献类型：
--
作者：
Xiao T;Zhu JJ;Huang S;Peng C;He S;Du J;Hong R;Chen X;Bode AM;Jiang W;Dong Z;Zheng D
活化T细胞核因子（NFAT）家族蛋白是在免疫应答期间调节促炎细胞因子和其它基因表达的转录因子。尽管NFAT蛋白在免疫系统中已被广泛研究，但其在癌症进展中的作用仍存在争议。在这里，我们报告NFAT 3在各种皮肤癌细胞系和肿瘤组织中高度表达。通过短发夹RNA（shRNA）敲低内源性NFAT 3表达显著抑制肿瘤细胞增殖、集落形成和锚定非依赖性细胞生长。此外，哺乳动物双杂交实验结果表明，细胞周期蛋白依赖性激酶3（CDK 3）直接与NFAT 3相互作用，并磷酸化NFAT 3的丝氨酸259（Ser 259），这增强了NFAT 3的反式激活和转录活性。NFAT 3的磷酸化位点对于表皮生长因子（EGF）刺激的HaCaT永生化皮肤细胞系的细胞转化是至关重要的，并且NFAT 3在Ser 259处的突变导致软琼脂中的集落形成减少。我们还发现，过度表达野生型NFAT 3，而不是突变型NFAT 3-S259 A，促进A431异种移植肿瘤生长。重要的是，我们发现，与正常皮肤组织相比，CDK 3，NFAT 3和磷酸化NFAT 3-Ser 259在皮肤癌中高度表达。这些结果提供了支持NFAT 3致癌潜力的证据，并表明CDK 3介导的NFAT 3磷酸化在皮肤肿瘤发生中具有重要作用。
The nuclear factor of activated T cells (NFAT) family proteins are transcription factors that regulate the expression of pro-inflammatory cytokines and other genes during the immune response. Although the NFAT proteins have been extensively investigated in the immune system, their role in cancer progression remains controversial. Here, we report that NFAT3 is highly expressed in various skin cancer cell lines and tumor tissues. Knockdown of endogenous NFAT3 expression by short hairpin RNA (shRNA) significantly inhibited tumor cell proliferation, colony formation and anchorage-independent cell growth. Furthermore, results of the mammalian two-hybrid assay showed that cyclin-dependent kinase 3 (CDK3) directly interacted with NFAT3 and phosphorylated NFAT3 at serine 259 (Ser259), which enhanced the transactivation and transcriptional activity of NFAT3. The phosphorylation site of NFAT3 was critical for epidermal growth factor (EGF)-stimulated cell transformation of the HaCaT immortalized skin cell line and mutation of NFAT3 at Ser259 led to a reduction of colony formation in soft agar. We also found that overexpressing wildtype NFAT3, but not mutant NFAT3-S259A, promoted A431 xenograft tumor growth. Importantly, we showed that CDK3, NFAT3 and phosphorylated NFAT3-Ser259 were highly expressed in skin cancer compared with normal skin tissues. These results provided evidence supporting the oncogenic potential of NFAT3 and suggested that CDK3-mediated phosphorylation of NFAT3 has an important role in skin tumorigenesis.