Yin H, Huang X, Tao M, Hu Q, Qiu J, Chen W, Wu J, Xie Y
Department of Oncology, The First Affiliated Hospital of Soochow University, Suzhou, China.
Department of Gastroenterology, The First Affiliated Hospital of Soochow University, Suzhou, China.
Cancer Gene Ther. 2017 Apr;24(4):180-188. doi: 10.1038/cgt.2017.3. Epub 2017 Feb 10.
Tumor necrosis factor (TNF)-alpha-induced protein 8-like 2 (TNFAIP8L2; also termed TIPE2) has been shown to be involved in both the immune-negative modulation and cancer. We previously found that TIPE2 is lost in human gastric cancer, and TIPE2 restoration suppresses gastric cancer growth by induction of apoptosis and impairment of protein kinase B (PKB/AKT) and extracellular signal-regulated kinase-1/2 (ERK1/2) signaling. However, its correlation with epithelial-mesenchymal transition (EMT) in gastric cancer is largely elusive. In the present report, we carried out a gain-of-function study in AGS and HGC-27 human gastric cancer cells by adenovirus-mediated human TIPE2 gene transfer (AdVTIPE2). We then examined the effects of AdVTIPE2 on in vitro migration and invasion of AGS and HGC-27 tumor cells by wound-healing assay and Transwell invasion assay, respectively. We also investigated the effects of AdVTIPE2 on in vivo lung metastasis of AGS and HGC-27 tumor cells by intravenous (i.v.) injection in athymic BALB/c nude mice. We demonstrated that AdVTIPE2 remarkably suppressed the migratory, invasive and metastatic potential of AGS and HGC-27 tumor cells in vitro and in vivo in BALB/c nude mouse model. Mechanistically, AdVTIPE2 obviously upregulated E-cadherin epithelial marker in AGS and HGC-27 tumor cells, whereas it downregulated N-cadherin and Vimentin mesenchymal markers, Snail1, Snail2/Slug and Zeb1 EMT-inducing transcription factors (EMT-TFs), and tripartite motif-containing 29 (TRIM29) and phosphatase regenerating liver 3 (PRL-3) gastric cancer-specific metastasis markers. Importantly, glycogen synthase kinase-3β (GSK-3β) inhibitor VIII and 26S proteasome inhibitor MG132 assays revealed that TIPE2 downregulated Snail1 and Snail2/Slug in a GSK-3β- and proteasome-dependent manner possibly by impairing AKT signaling. Our data provided the first evidence that TIPE2 inhibits gastric cancer cell migration, invasion and metastasis very probably via reversal of EMT, revealing that TIPE2 may be a novel therapeutic target for human gastric cancer EMT and metastasis.
肿瘤坏死因子（TNF）-α诱导蛋白8样2（TNFAIP8L2；也称为TIPE2）已被证明参与免疫负调节和癌症过程。我们之前发现TIPE2在人类胃癌中缺失，并且TIPE2的恢复通过诱导细胞凋亡以及损害蛋白激酶B（PKB/AKT）和细胞外信号调节激酶-1/2（ERK1/2）信号传导来抑制胃癌生长。然而，其与胃癌上皮-间质转化（EMT）的相关性在很大程度上仍不清楚。在本报告中，我们通过腺病毒介导的人类TIPE2基因转移（AdVTIPE2）在AGS和HGC-27人胃癌细胞中进行了功能获得性研究。然后，我们分别通过伤口愈合试验和Transwell侵袭试验检测了AdVTIPE2对AGS和HGC-27肿瘤细胞体外迁移和侵袭的影响。我们还通过在无胸腺BALB/c裸鼠中静脉内（i.v.）注射检测了AdVTIPE2对AGS和HGC-27肿瘤细胞体内肺转移的影响。我们证明AdVTIPE2在体外和BALB/c裸鼠模型体内均显著抑制了AGS和HGC-27肿瘤细胞的迁移、侵袭和转移潜能。机制上，AdVTIPE2明显上调了AGS和HGC-27肿瘤细胞中的E-钙黏蛋白上皮标记物，而它下调了N-钙黏蛋白和波形蛋白间质标记物、Snail1、Snail2/Slug和Zeb1 EMT诱导转录因子（EMT-TFs），以及含三联基序的29（TRIM29）和磷酸酶再生肝3（PRL-3）胃癌特异性转移标记物。重要的是，糖原合酶激酶-3β（GSK-3β）抑制剂VIII和26S蛋白酶体抑制剂MG132试验表明，TIPE2可能通过损害AKT信号传导以GSK-3β和蛋白酶体依赖性方式下调Snail1和Snail2/Slug。我们的数据首次提供了证据，表明TIPE2很可能通过逆转EMT来抑制胃癌细胞的迁移、侵袭和转移，揭示了TIPE2可能是人类胃癌EMT和转移的一个新的治疗靶点。
