Table_1_Porf-2 Inhibits Tumor Cell Migration Through the MMP-2/9 Signaling Pathway in Neuroblastoma and Glioma.DOCX

Tumor migration and invasion are key pathological processes that contribute to cell metastasis as well as treatment failure in patients with malignant tumors. However, the mechanisms governing tumor cell migration remain poorly understood. By analyzing the tumor-related database and tumor cell lines, we found that preoptic regulatory factor-2 (Porf-2) is downexpressed in both neuroblastoma and glioma. Using in vitro assays, our data demonstrated that the expression of Porf-2 inhibits tumor cell migration both in neuroblastoma and glioma cell lines. Domain-mutated Porf-2 plasmids were then constructed, and it was found that the GAP domain, which plays a role in the inactivation of Rac1, is the functional domain for inhibiting tumor cell migration. Furthermore, by screening potential downstream effectors, we found that Porf-2 can reduce MMP-2 and MMP-9 expression. Overexpression of MMP-2 blocked the inhibitory effect of Porf-2 in tumor cell migration both in vitro and in vivo. Taken together, we show for the first time that Porf-2 is capable of suppressing tumor cell migration via its GAP domain and the downregulation of MMP-2/9, suggesting that targeting Porf-2 could be a promising therapeutic strategy for nervous system tumors.

肿瘤迁移与侵袭是导致恶性肿瘤患者发生细胞转移以及治疗失败的关键病理过程。然而，目前学界对调控肿瘤细胞迁移的分子机制仍缺乏深入认知。通过分析肿瘤相关数据库与肿瘤细胞系，我们发现视前区调控因子-2（preoptic regulatory factor-2, Porf-2）在神经母细胞瘤与胶质瘤中均呈现低表达状态。借助体外实验体系，我们的研究数据证实，Porf-2的表达可同时抑制神经母细胞瘤与胶质瘤细胞系的肿瘤细胞迁移能力。随后我们构建了结构域突变的Porf-2质粒，实验结果显示，介导Rac1失活的GAP结构域（GAP domain）正是Porf-2发挥肿瘤细胞迁移抑制作用的功能结构域。此外，通过筛选潜在下游效应因子，我们发现Porf-2可下调基质金属蛋白酶-2（matrix metalloproteinase-2, MMP-2）与基质金属蛋白酶-9（matrix metalloproteinase-9, MMP-9）的表达水平。过表达MMP-2可在体外与体内实验中阻断Porf-2对肿瘤细胞迁移的抑制效应。综上，我们首次证实，Porf-2可通过其GAP结构域并下调MMP-2/9的表达来抑制肿瘤细胞迁移，这提示靶向调控Porf-2有望成为神经系统肿瘤的潜在治疗策略。