目的：探讨叉头框蛋白D3（forkhead box protein D3，FOXD3）在胃贲门腺癌（gastric cardia adenocarcinoma，GCA）中的表达及其对SGC-7901细胞生物学行为的影响。方法：从河北医科大学第四医院生物标本库中选取2014年6月至2016年12月手术切除的 49 例 GCA 组织及相应癌旁组织标本，qRT-PCR 检测 FOXD3 在 GCA 组织、癌旁组织以及在 5 种胃癌细胞系中（BGC-823、SGC-7901、HGC-27、MGC-803及NCI-N87）的表达。向 SGC-7901细胞转染pc-DNA3.1-FOXD3或pc-DNA3.1，采用细胞增殖实验、克隆形成实验、划痕愈合实验和Transwell小室侵袭实验分别检测FOXD3过表达对SGC-7901细胞增殖、克隆形成、迁移和侵袭的影响，qRT-PCR及WB法检测细胞转染前后上皮-间质转化（epithelial-mesenchymal transition，EMT）相关分子mRNA及蛋白的表达情况，流式细胞术检测转染前后细胞周期改变。结果：GCA组织中FOXD3 mRNA的表达量明显降低，其表达水平与患者临床分期和淋巴结转移密切关联 ；FOXD3 在胃癌细胞系中的表达均低于正常细胞（均P<0.01）。FOXD3过表达能明显抑制SGC-7901细胞的增殖、克隆形成、迁移和侵袭能力（均P<0.01），提高SGC-7901细胞中E-cadherin的表达水平，减少N-cadherin、β-catenin和vimentin的表达水平（均P<0.01），使细胞周期阻滞在G0/G1期（P<0.01）。结论: FOXD3在GCA组织中的表达明显下调，其过表达可以抑制胃癌细胞的生物学行为，FOXD3可作为抑癌基因为肿瘤治疗提供新思路。

Objective: To investigate the expression of forkhead box protein D3 (FOXD3) in gastric cardia adenocarcinoma (GCA) and its effect on the biological behaviors of SGC-7901 cells. Methods: A total of 49 pairs of GCA tissues and corresponding para[1]cancerous tissues that surgically resected from June 2014 to December 2016 were selected from the Biological Specimen Library of the Fourth Hospital of Hebei Medical University. qRT-PCR was used to detect the expression of FOXD3 in GCA tissues and corresponding para-cancerous tissues, as well as in gastric cancer cell lines（BGC-823, SGC-7901, HGC-27, MGC-803, and NCI-N87）. pc-DNA3.1-FOXD3 or pc-DNA3.1 was transfected into SGC-7901 cells. Cell proliferation assay, clone formation assay, scratch healing assay, and Transwell chamber invasion assay were used to detected the effect of FOXD3 overexpression on the the proliferation, clone formation,migration, and invasion of SGC-7901 cells. The mRNA and protein expressions of epithelial-mesenchymal transition (EMT) related molecules before and after the transfection were detected by qRT-PCR and WB. Cell cycle changes before and after transfection were detected by Flow cytometry. Results: The expression of FOXD3 mRNA in GCA tissues was significantly downregulated, and it's expression was closely correlated with clinical stage and lymph node metastasis of GCA patients. The expression of FOXD3 in gastric cancer cell lines was lower than that in normal cell lines (all P<0.01). FOXD3 overexpression significantly inhibited the proliferation,clone formation, migration and invasion of SGC-7901 cells in vitro (all P<0.01). FOXD3 overexpression could up-regulate the expression of E-cadherin and down-regulate the expressions of N-cadherin, β -catenin and vimentin in SGC-7901 cells (all P<0.01). Overexpression of FOXD3 could arrest the cell cycle in the G0/G1 phase (P<0.01). Conclusion: The expression of FOXD3 in GCA tissues is significantly downregulated, and its overexpression can inhibit the biological behaviors of gastric cancer cells. FOXD3 can be used as a tumor suppressor gene to provide new ideas for tumor therapy.

河北 省 自 然 科 学 基 金 面 上 项 目 资 助（No. H2019206664）