LincRNA-p21敲减对胃癌细胞生长和转移的影响及其作用机制

目的：探讨LincRNA-p21敲减对胃癌细胞增殖、迁移与侵袭的影响，并阐明其作用机制。方法：采用实时荧光定量聚合酶链反应（RT-qPCR）法检测胃癌组织、癌旁组织以及3种胃癌细胞（MGC-803、MKN-45和SGC-790）和正常胃黏膜上皮细胞GES-1中LincRNA-p21mRNA表达水平。以MGC-803细胞作为研究对象，实验分为sh-NC组、sh-LincRNA-p21组和AG490+sh-LincRNA-p21组。sh-NC组MGC-803细胞采用慢病毒感染sh-NC；sh-LincRNA-p21组MGC-803细胞采用慢病毒感染sh-LincRNA-p21；AG490+sh-LincRNA-p21组MGC-803细胞采用慢病毒感染sh-LincRNA-p21后，再采用10 μg·L^-1 AG490处理细胞。采用5-乙炔基-2'-脱氧尿苷（EdU）掺入法检测各组MGC-803细胞EdU掺入百分比，CCK-8法检测各组MGC-803细胞活性，Transwell法检测各组MGC-803细胞迁移数和侵袭数，Western blotting法检测sh-NC组和sh-LincRNA-p21组MGC-803细胞中p-JAK1、p-STAT3和p-STAT5蛋白表达水平。将sh-NC组和sh-LincRNA-p21组MGC-803细胞移植入BALB/c裸鼠颈部皮下成瘤，检测瘤体体积和质量。结果：与癌旁组织比较，胃癌组织中LincRNA-p21mRNA表达水平明显降低（P<0.01）；与GES-1细胞比较，MGC-803、MKN-45和SGC-790细胞中LincRNA-p21表达水平均明显降低（P<0.01）。与sh-NC组比较，sh-LincRNA-p21组MGC-803细胞EdU掺入百分比、细胞活性、细胞迁移数和侵袭数、p-JAK1、p-STAT3和p-STAT5蛋白表达水平均明显升高（P<0.05或P<0.01）；与sh-LincRNA-p21组小鼠比较，AG490+sh-LincRNA-p21组MGC-803细胞活性、细胞迁移数和侵袭数均明显降低（P<0.05或P<0.01）。裸鼠成瘤实验，与sh-NC组比较，sh-LincRNA-p21组小鼠瘤体体积和质量均明显增加（P<0.05或P<0.01）。结论：敲减LincRNA-p21可明显促进胃癌细胞的生长与转移，且该促进作用可能与其促进JAK-STAT信号通路活性有关。

Effects of LincRNA-p21 knockdown on growth and metastasis of gastric cancer cells and their mechanisms

Objective: To investigate the effects of LincRNA-p21 knockdown on the proliferation, migration and invasion of gastric cancer cells, and to elucidate their mechanisms. Methods: The expression levels of LincRNA-p21 mRNA in the gastric cancer tissue, adjacent tissue, three types of gastric cancer cells (MGC-803, MKN-45 and SGC-790 cells) and normal gastric mucosal epithelial cells GES-1 were detected by real-time quantitative polymerase chain reaction (RT-qPCR). The MGC-803 cells were used as the subjects and were divided into sh-NC group, sh-LincRNA-p21 group and AG490+sh-LincRNA-p21 group. The MGC-803 cells in sh-NC group were infected with sh-NC by lentivirus; the MGC-803 cells in sh-LincRNA-p21 group were infected with sh-LincRNA-p21 by lentivirus; the MGC-803 cells in AG490+sh-LincRNA-p21 group were infected with sh-LincRNA-p21 by lentivirus, and then treated with 10 μg·L^-1 AG490. The percentages of 5-ethynyl-2'-deoxyuridine (EdU) incorporation of the MGC-803 cells in various groups were detected by EdU incorporation assay. The viabilities of MGC-803 cells in various groups were measured by CCK-8 assay. The number of invasion and migration of MGC-803 cells in various groups was detected by Transwell assay. The expression levels of p-JAK1, p-STAT3 and p-STAT5 proeteins in the MGC-803 cells in sh-NC group and sh-LincRNA-p21 group were detected by Western blotting method. The MGC-803 cells from sh-NC group and sh-LincRNA-p21 group were subcutaneouly transplanted into the neck of the BALB/c nude mice, then the volumes and weights of the tumors of the mice were measured. Results: Compared with adjacent tissue, the expression level of LincRNA-p21 mRNA in gastric cancer tissue was significantly decreased (P<0.01); compared with the GES-1 cells, the expression levels of LincRNA-p21 mRNA in the MGC-803, MKN-45 and SGC-790 cells were significantly decreased (P<0.01).Compared with sh-NC group, the percentage of EdU incorporation, the cell viability, the number of migration and invasion cells, the expression levels of p-JAK1, p-STAT3 and p-STAT5 proteins in the MGC-803 cells in sh-LincRNA-p21 group were significantly increased (P<0.05 or P<0.01).Compared with sh-LincRNA-p21 group, the cell viability and the number of migration and invasion of the MGC-803 cells in AG490+sh-LincRNA-p21 group were significantly decreased (P<0.05 or P<0.01).The results of the tumorigenesis of nude mice showed that compared with sh-NC group, the volume and weight of the tumor of the mice in sh-LincRNA-p21 group were significantly increased (P<0.05 or P<0.01). Conclusion: LincRNA-p21 knockdown can significantly promote the growth and metastasis of gastric cancer cells, and this promotion may be related to promoting the activity of JAK-STAT signaling pathway.