胃癌腹膜转移提示患者预后极差，转移机制尚待深入。前期发现NMMHC-IIA在胃正常上皮、胃癌原发灶和腹膜转移灶间递增表达；TALEN质粒和慢病毒构建NMMHC-IIA敲低和过表达稳转细胞株并发现CTNNB1表达与NMMHC-IIA水平呈正相关，且敲低NMMHC-IIA促进胃癌细胞失巢凋亡；NMMHC-IIA存在核定位，可识别CTNNB1启动子区、促进其转录；星孢菌素可抑制核NMMHC-IIA蛋白S1943磷酸化和CTNNB1转录。结合文献及前期实验提出假设，NMMHC-IIA调控CTNNB1转录促进胃癌细胞失巢凋亡抵抗及腹膜转移。后续拟通过细胞实验和原位种植瘤模型验证NMMHC-IIA 是否通过上调CTNNB1表达增强失巢凋亡抵抗促进胃癌腹膜转移；明确NMMHC-IIA核定位信号及DNA结合域；通过原位种植瘤模型验证星孢菌素体内抑癌效果。本研究有助于探索胃癌腹膜转移新机制，寻找药物靶点。

Peritoneal metastasis of gastric cancer (GC) always indicates very poor survival, and its molecular mechanism is still far from being uncovered. In this study, we had found that NMMHC-IIA expression was stepwise increased in nontumorous gastric mucosa, primary gastric cancer tissues and peritoneal metastatic foci by two-dimensional fluorescent differential gel electrophoresis (2D-DIGE) and matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-TOF/TOF MS). We also found its expression was negatively associated with GC patients' survival. Then, we knocked down and up-regulated NMMHC-IIA's expression in gastric cancer cell lines by TALEN-mediated knockdown and lentivirus-mediated gene transfection. Unexpectedly, we found the expression of CTNNB1 was postively associated with the expression of NMMHC-IIA. Moreover, the number of gastric cancer cells' anoikis in soft agar increased after knocking down their expression of NMMHC-IIA. Besides, we found NMMHC-IIA largely located in the nucleus of gastric cancer cells, and specifically recognized CTNNB1 promoter to regulate its transcription. We also found staurosporine could inhibite S1943 phosphorylation of nuclear NMMHC-IIA and the expression of CTNNB1. Based on above results and literature we read, we hypothesized that NMMHC-IIA promoted anoikis resistance and peritoneal metastasis of gastric cancer cells by regulating CTNNB1 transcription. We planned to use cell experiments and orthotropic GC models to confirm whether NMMHC-IIA promoted anoikis resistance and peritoneal metastasis of gastric cancer cells by increasing CTNNB1 expression. We also wanted to know the nuclear localization signal and DNA binding domains of NMMHC-IIA. Lastly, we would confirm whether staurosporine could inhibit peritoneal metastasis of gastric cancer cells in orthotropic GC models. This study is helpful to uncover the new mechanisms of gastric cancer peritoneal metastasis and good for looking for drug targets.