CK2A2在miR-1228*/NF-κB反馈环路调控胃癌EMT中的作用及分子机制研究

上皮间质转化（EMT）在胃癌的侵袭和转移中起重要作用。我们前期研究发现胃癌中miR-1228*低表达，过表达miR-1228*能明显抑制胃癌细胞的EMT，并且miR-1228*和NF-κB形成反馈调节环路，提示miR-1228*/NF-κB反馈环路的动态平衡决定了胃癌细胞的上皮或间质表型，miR-1228*直接作用的靶基因CK2A2可能是此反馈环路的关键调控基因，然而其作用机制目前尚不清楚。因此，本项目拟在先前研究基础上：首先观察胃癌中CK2A2与miR-1228*和NF-κB之间的相关性；进而构建CK2A2慢病毒载体，建立稳转胃癌细胞株，检测EMT相关蛋白的表达和细胞迁移；最后探讨CK2A2对NF-κB活性和miR-1228*表达的影响。本研究对于阐明miR-1228*/NF-κB反馈环路调控胃癌EMT的分子机制以及CK2A2的作用机制提供理论依据，为胃癌的有效干预阻断提供潜在候选靶点。

Epithelial-mesenchymal transition (EMT) plays an important role in the invasion and metastasis of gastric cancer. Activation of NF-κB has been shown to promote EMT while inhibition of NF-κB activity in mesenchymal cell causes a reversal of EMT. In our previous study, the function of miR-1228* in regulating cancer progression was investigated in gastric cancer. Decreased expression of miR-1228* was observed in human gastric cancer tissues comparing to normal tissues. Overexpression of miR-1228 significantly inhibited EMT of gastric cancer cells. It was shown that NF-κB activation was responsible for the lower expression of miR-1228*, and miR-1228* suppressed NF-κB activity. Taken together, the results indicated a feedback loop between miR-1228* expression and NF-κB activity. But the exact mechanism of how this feedback loop occurs is still not clear. CK2A2, which is one of the targets of miR-1228*, may play the key role in the miR-1228*/NF-κB feedback loop. Therefore, we intend to observe the correlation between CK2A2, miR-1228* and NF-κB in gastric cancer tissues and cell lines. Then the lentiviral vectors of CK2A2 and CK2A2-shRNA are constructed, and the stable-transfection gastric cancer cells are established. After that, EMT-associated proteins and cell migration are detected in stable-transfection gastric cancer cells. Finally, we investigate the effect of CK2A2 on the activity of NF-κB and the expression of miR-1228*. This study provides a theoretical basis for clarifying the functional role and molecular mechanisms of CK2A2 on regulating EMT by participating miR-1228*/NF-κB feedback loop in gastric cancer, and it offers suggestions for potential candidate targets on gastric cancer treatment.