[摘要] 目的：探讨长链非编码RNA（long non-coding RNA，lncRNA）SNHG16 在结直肠癌（colorectal cancer，CRC）组织和细胞中的表达及其通过海绵吸附miR-128-3p 调控结肠癌细胞线粒体甘油3 磷酸酰基转移酶基因（mitochondrial glycerol-3-phosphateacyltransferase，GPAM）表达的分子机制。方法：收集2014 年1 月至2017 年1 月甘肃省人民医院肛肠科手术切除的60 例CRC患者的癌及癌旁组织标本，以及结直肠癌细胞系SW480、SW620、HCT116、Caco-2、DLD-1、HT29 和结肠上皮细胞CCD841，用qPCR法检测CRC组织和细胞系中SNHG16 的表达，分析SNHG16 表达与CRC患者临床病例特征的关系。分别用miR-128-3p模拟物、miR-128-3p 抑制剂、SNHG16 敲降载体转染SW480 细胞后，用qPCR 法检测细胞中miR-128-3p 及SNHG16 mRNA的表达，用Western blotting 法检测GPAM蛋白的表达，用CCK-8 法、克隆形成实验及细胞凋亡实验、Transwell 小室法检测细胞的增殖、凋亡及侵袭。用双荧光素酶报告基因法和RNA免疫共沉淀实验验证SNHG16 和miR-128-3p mRNA靶向结合。构建小鼠SW480细胞移植瘤模型，观察敲降SNHG16 对移植瘤生长的影响。结果：CRC组织及细胞系中SNHG16 高表达（均P<0.01），其表达水平与CRC淋巴结转移、Duke’s 分期及患者生存期相关（均P<0.01）。敲降SNHG16 可显著抑制SW480 细胞的增殖及侵袭能力，并诱导细胞凋亡（均P<0.01）；敲降SNHG16 后小鼠移植瘤瘤体显著小于对照组(P<0.05)。双荧光素酶报告基因检测及RNA免疫沉淀反应结果显示，miR-128-3p 与SNHG16 相互作用，且在CRC患者中miR-128-3p 与SNHG16 负相关（P<0.01)。SNHG16 通过内源性竞争海绵吸附miR-128-3p 影响其下游靶基因GPAM的表达。结论：SNHG16 在CRC细胞中可通过海绵吸附miR-128-3p 调控GPAM表达，SNHG16及miR-128-3p 可作为CRC诊断及治疗的潜在靶点。

[Abstract] Objective: To investigate the expression of long non-coding RNA SNHG16 (lncRNA SNHG16) in colorectal cancer (CRC)tissues and cells, and to explore the mechanism of its regulation on the expression of mitochondrial glycerol-3-phosphate acyltransferase (GPAM) via sponging miR-128-3p. Methods: Sixty pairs of colorectal cancerous tissues and para-cancerous tissues that resected from CRC patients, who underwent surgery in the Department of Anorectal Surgery, Gansu Provincial People’s Hospital during Jan.2014 and Jan. 2017, were collected for this study; In addition, CRC cell lines (SW480, SW620, HCT116, Caco-2,DLD-1, HT29) and colonic epithelial cell line CCD841 were also collected for the study. The expression of SNHG16 in collected tissues and cell lines was determined by Real-time quantitative PCR (qPCR), and its correlation to the clinicopathological features of CRC patients was also analyzed.SW480 cells were transfected with miR-128-3p mimic, miR-128-3p inhibitor, and si-SNHG16, respectively, and then the mRNA expressions of miR-128-3p and SNHG16 were detected by qPCR, the protein expression of GPAM was determined by Western blotting,and the cell proliferation, apoptosis and invasion were detected by CCK-8 assay, colony formation assay, cell apoptosis assay and Transwell chamber assay, respectively. The binding between SNHG16 and miR-128-3p was validated with dual luciferase reporter gene assay and RNA Immunoprecipitation assay. For in vivo experiment, mouse model of SW480 cell exnograft was constructed, and the ef-fect of SNHG16 knockdown on the growth of exnograft was observed. Results: SNHG16 was found to highly expressed in human CRC tissues and cell lines (all P<0.01), and SNHG16 expression level was associated with lymph node metastasis, Duke's stage and patients’survival (all P<0.01). Knockdown of SNHG16 significantly inhibited CRC cell proliferation and invasion, and induced apoptosis (all P<0.01); After SNHG16 knockdown, the volume of exnograft was obviously reduced (P<0.05). Dual luciferase reporter gene assay and RNA Immunoprecipitation assay validated the interaction between miR-128-3p and SNHG16, and they were negatively correlated with each other in CRC patients (P<0.01). The SNHG16 regulated the expression of its down-stream gene GPAM via endogenously sponging miR-128-3p. Conclusion: SNHG16 regulates GPAM expression in CRC cells by sponging miR-128-3p, and SNHG16 and miR-128-3p may serve as potential targets for the diagnosis and treatment of CRC.

国家自然科学基金资助项目（No.81460677）