目的：探讨含SET结构域蛋白5（SETD5）对结肠癌细胞增殖、迁移和对5-氟尿嘧啶（5-FU）药物敏感性的影响及机制。方法：常规培养结肠癌细胞，用Lipofectamine 2000将siSETD5-NC、si-SETD5-1~3质粒转染至HT-29细胞中，将其分为对照组（未处理）、si-SETD5-NC组、si-SETD5组和si-SETD5+SC79组，si-SETD5+SC79组HT-29细胞转染质粒的同时用10 μmol/L SC79处理。qPCR法检测NCM460、HT-29和LoVo细胞中SETD5 mRNA表达，流式细胞术、细胞划痕法、WB法和CCK-8法分别检测各组HT-29细胞的凋亡情况、迁移能力、相关蛋白的表达，以及对5-FU 的敏感性。结果：SETD5 mRNA在HT-29、LoVo细胞中均呈高表达（均P<0.01）。在HT-29细胞中成功地敲减了SETD5 mRNA（P<0.01）。敲减SETD5 mRNA可明显抑制HT-29细胞的增殖活性（P<0.01）、迁移能力（P<0.01）、相关蛋白（SETD5、p-PI3K、p-AKT1、p-mTOR 蛋白）的表达（均P<0.01）、促进细胞凋亡（P<0.01），且提高其对 5-FU 的敏感性（P<0.01），这些作用均可被 AKT 激活剂 SC79 部分阻挡（P<0.05 或 P<0.01）。结论：SETD5在HT-29、LoVo细胞中高表达，SETD5通过PI3K/AKT1通路促进结肠癌HT-29细胞的增殖、迁移，且降低其对5-FU的敏感性，SETD5是结肠癌临床诊断、治疗的潜在靶点。

Objective: To investigate the effect of SET domain-containing 5 (SETD5) on the proliferation, migration and 5-fluorouracil (5-FU) drug sensitivity of colon cancer cells and its mechanism. Methods: Colon cancer cells were cultured routinely, and siSETD5-NC and si-SETD5-1-3 plasmids were transfected into HT-29 cells with Lipofectamine 2000. The cells were divided into the control group (untreated), the si-SETD5-NC group, the si-SETD5 group and the si-SETD5+SC79 group. The HT-29 cells in the si-SETD5+SC79 group were transfected with plasmids and treated simultaneously with 10 μmol/L SC79. SETD5 mRNA expression in NCM460, HT-29 and LoVo cells was detected by qPCR. Flow cytometry, cell scratch method, WB method and CCK-8 method were used to detect the apoptosis, migration ability, expression of related proteins and sensitivity to 5-FU of HT-29 cells in each group, respectively. Results: SETD5 mRNA was highly expressed in both HT-29 and LoVo cells (both P<0.01). SETD5 mRNA was successfully knocked down in HT-29 cells (P<0.01). Knockdown of SETD5 mRNA could significantly inhibit the proliferation activity (P<0.01), migration ability (P<0.01), expression of related proteins (SETD5, p-PI3K, p-AKT1, p-mTOR protein) of HT-29 cells (all P<0.01), promote apoptosis (P<0.01), and increase the sensitivity to 5-FU (P<0.01). These effects could be partially blocked by AKT activator SC79 (P<0.05 or P<0.01). Conclusion: SETD5 is highly expressed in HT-29 and LoVo cells. SETD5 promotes the proliferation and migration of colon cancer HT-29 cells and reduces sensitivity to 5-FU through PI3K/AKT1 pathway. SETD5 is a potential target for clinical diagnosis and treatment of colon cancer.

2021年武汉市中心医院学科基金项目（No. 2021XK063）