目的：探讨聚二磷酸腺苷核糖聚合酶 1（PARP1）对胃癌AGS细胞的增殖和5-FU耐药性的影响及其可能的机制。方法：收集2018年5月至2019年12月于恩施土家族苗族自治州中心医院就诊的72例胃癌患者的肿瘤组织和癌旁组织，采用qPCR和免疫组化法检测胃癌和癌旁组织中PARP1的表达状况。CCK-8法、流式细胞术和集落形成实验分别检测PARP1抑制剂AG14361对胃癌AGS细胞增殖、凋亡和集落形成的影响，MTT法检测AG14361对胃癌细胞5-FU敏感性的影响。mRNA测序分析AG14361处理AGS细胞后差异基因整体分布情况，KEGG富集分析相关信号通路。向AGS细胞转染siFUT8以敲减FUT8基因的表达，qPCR和WB法检测AGS细胞内α-1,6-岩藻糖基转移酶（FUT8）的表达状况和敲减FUT8效果，CCK-8法、流式细胞术和集落形成实验分别检测AG14361处理对敲减FUT8表达的AGS细胞增殖、凋亡和集落形成的影响。结果：与癌旁组织相比，胃癌组织中PARP1呈高表达（P<0.001）。AG14361 处理可显著抑制 AGS 细胞的增殖和细胞集落形成，促进AGS细胞凋亡（均P<0.01）。AG14361处理可降低5-FU杀伤胃癌细胞的IC50，且在 AGS 细胞中尤为明显 ，IC50 下降超过 60%。mRNA测序结果显示，N-糖基化修饰中FUT8是AG14361抑制AGS细胞增殖的关键糖基转移酶（P<0.05）。与siNC组相比，IC50浓度的AG14361可显著逆转干扰FUT8对AGS细胞增殖的增加，促进细胞凋亡和BAX蛋白表达、抑制Bcl2蛋白表达，抑制FUT8干扰所致AGS细胞集落的增加（均P<0.01）。结论：PARP1可通过调控N-糖基转移酶FUT8促进胃癌细胞恶性转化，其抑制剂AG14361可增强胃癌细胞对5-FU的敏感性，PARP1可能成为胃癌治疗的一个潜在靶标。

Objective: To investigate the effect of polyadenosine diphosphate ribose polymerase 1 (PARP1) on the proliferation and 5-FU resistance of gastric cancer cells and its potential mechanism. Methods: The tumor tissues and corresponding paracancerous tissues of 72 patients with gastric cancer who were treated in Central Hospital of Enshi Tujia and Miao Autonomous Prefecture from May 2018 to December 2019 were collected. AGS cells were transfected with siFUT8 to knock down FUT8 gene expression. qPCR and immunohistochemistry were used to detect the expression of PARP1 in gastric cancer and adjacent tissues. CCK-8, flow cytometry, and colony formation assay were employed to detect the effects of AG14361 on the proliferation, apoptosis and colony formation of AGS cells. MTT assay was used to detect the effect of AG14361 on the 5-FU sensitivity of gastric cancer cells. The overall distribution of differential genes in AGS cells treated with AG14361 was analyzed by mRNA sequencing, and related signaling pathways were analyzed by KEGG enrichment. qPCR and WB were used to detect the expression of α-1,6-fucosyltransferase (FUT8) in AGS cells and the interference effect of FUT8. CCK-8, flow cytometry, and colony formation assay were employed to detect the effects of AG14361 on the proliferation, apoptosis, and colony formation of AGS cells disturbed by siFUT8. Results: Compared with paracancer tissues, PARP1 expression was significantly increased in gastric cancer tissues (P<0.001). AG14361 can significantly inhibit the proliferation and colony formation of AGS cells, thus promoting the apoptosis of AGS cells (all P<0.01). AG14361 treatment reduced the IC50 of 5-FU against gastric cancer cells, especially against AGS cells, with IC50 decreased by more than 60%. mRNA sequencing results showed that FUT8 was a key glycosyltransferase of AG14361 in inhibiting the proliferation of AGS cells (P<0.05). Compared with the siNC group, treatment of AG14361 with IC50 significantly reversed the promotion of AGS cells proliferation caused by inerference with FUT8, promoted apoptosis and BAX protein expression, decreased Bcl2 protein expression and inhibited the increase in AGS cell colony formation caused by interference with FUT8 (all P<0.01). Conclusion: PARP1 can promote malignant transformation of gastric cancer cells by regulating N-glycosyltransferase FUT8. AG14361 can enhance the chemotherapy sensitivity of 5-FU, and PARP1 may become a potential target for gastric cancer treatment.

R735.2；R730.2

国家自然科学基金资助项目（No. 81760540）