徐王彦 刘忠臣

摘 要：目的 探究lncRNA MEG8对结肠癌细胞增殖、侵袭和凋亡的作用，阐明其作用机制。方法 利用实时荧光定量PCR（Real Time-Quantitative PCR，RT-qPCR）检测MEG8和miR-1827表达;Western blotting和CCK-8检测蛋白表达和细胞增殖;Transwell和流式细胞术检测细胞侵袭和凋亡;双荧光素酶报告基因试验和RNA免疫沉淀反应（RNA Immunoprecipitation，RIP）验证MEG8与miR-1827结合。结果 MEG8通过结合miR-1827负调控miR-1827表达。与人正常结肠上皮细胞相比，MEG8在结肠癌细胞中表达下调，而miR-1827表达上调。过表达MEG8或干扰miR-1827抑制HT29细胞增殖和侵袭，促进凋亡。沉默miR-1827逆转干扰MEG8诱导的细胞增殖和侵袭上升，凋亡和细胞外调节蛋白激酶（extracellular regulated protein kinases，ERK）/ c-Jun氨基末端激酶（c-Jun N-terminal kinase，JNK）通路活性下降。结论 LncRNA MEG8通过下调miR-1827，促进ERK/JNK通路活性，阻碍结肠癌细胞HT29增殖和侵袭，促进凋亡。

关键词：结肠癌;lncRNA MEG8;miR-1827;增殖;凋亡;侵袭

Abstract：Objective To explore the role of lncRNA MEG8 in the proliferation， invasion and apoptosis of colon cancer cells and the possible molecular mechanisms involved. Methods Real Time-Quantitative PCR （RT-qPCR）was used to detect the expression of MEG8 and miR-1827. Western blotting and CCK-8 assays were used to detect protein levels and cell proliferation. Transwell assay and flow cytometry were performed to measure cell invasion and apoptosis. Dual luciferase reporter gene and RNA Immunoprecipitation （RIP）assays were used to verify the relationship between MEG8 and miR-1827. Results MEG8 negatively regulated miR-1827 expression by binding with miR-1827. MEG8 was down-regulated in colon cancer cells， while miR-1827 was up-regulated， compared with their expression in normal human colon epithelial cells. The overexpression of MEG8 or interference to miR-1827 inhibited HT29 cells proliferation and invasion and promoted their apoptosis，while the silence of miR-1827 would reverse such MEG8-induced effects and decrease the pathway activity of ERK （extracellular regulated protein kinases）/JNK （c-Jun N-terminal kinase）. Conclusion LncRNA MEG8 will increase the activity of ERK/JNK pathway with miR-1827 down-regulaed， thereby inhibiting the proliferation and invasion of the HT29 colon cancer cells， and promoting their apoptosis.

Key words：colon cancer; LncRNA MEG8; miR-1827; proliferation; apoptosis; invasion

結直肠癌是世界上第三种最常见的癌症，占人类癌症相关死亡人数的1/10。由于其发展迅速且隐蔽，每年新增结肠癌人数超过12万，死亡率超过33%[1-2]。尽管诊断和治疗策略不断进步，但结肠癌患者的预后在过去十年间未发生显著变化[3]。目前只有少数生物标记物可用于结肠癌的预防，因此，鉴定早期诊断结肠癌的分子标志物具有重要意义。

长非编码RNA（LncRNA）是长度超过200nt但没有蛋白质编码能力的RNA分子。LncRNA可以作为肿瘤中的癌基因或抑癌基因，参与肿瘤增殖、转移、自噬和凋亡等调控[4]5 752。多种lncRNA异常与结肠癌进展密切相关。据报道，与正常结肠组织相比，母系表达基因8（matemally expressed gene 8，MEG8）在结肠癌组织中表达下调，但其参与结肠癌发病的潜在机制尚不清楚[5]。MicroRNA（miRNAs）是一类约22个核苷酸的非编码小RNA，其失调与多种生物学过程，包括细胞增殖，分化和凋亡相关。……