Peritoneal metastasis is one of the most important causes of postoperative death in patients with gastric cancer, and the exact mechanism remains unclear. The proliferation of multicellular aggregates of exfoliated malignant gastric cells in the abdominal cavity is the focus of current research. However, the mechanism how gastric cancer multicellular aggregates survive remains unclear. In this study, we demonstrated that multicellular aggregates of exfoliated gastric cancer cells in the abdominal cavity expressed a stem cell-Like phenotype. We found that Integrin α v β 3 not only mediated adhesion of gastric cancer multicellular aggregates to form independent functional units, but also maintained their stem cell-like phenotype by the non-classical pathway Integrin α v β 3 /ERK1/2/GLI1. In addition, ERK1/2 directly regulates the transcriptional activity of GLI1. GLI1 is a key effector of the Integrin α v β 3 pathway in regulating stem cell-like phenotype in multicellular aggregates. Our data indicates that although there is a crosstalk between the non-classical Integrin α v β 3 pathway and the classical Hedgehog pathway, the activation of GLI1 is almost independent of the Hedgehog pathway in multicellular aggregates of gastric cancer cells. Our study provides a basis for blocking GLI1 activity in the prevention and treatment of peritoneal metastases of gastric cancer.

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Background: The efficacy of pelvic floor peritoneum closure (PC) during endoscopic low anterior resection (E-LAR) of rectal cancer remains unclear. This study aimed to clarify whether pelvic floor PC affected short-term outcomes. Methods: The study group comprised patients with the pathologically confirmed diagnosis of rectal cancer who underwent E-LAR with pelvic floor PC or with no PC (NPC) between January 2013 and December 2018 in Southwest Hospital. After propensity score matching (PSM), 584 patients (292 who underwent PC and 292 who underwent NPC) were evaluated. Postoperative indicators, including the rates of complications, anastomotic leakage (AL), reoperation, and inflammation, were observed in the two groups. Results: No significant difference was observed in the rates of postoperative complications between the PC and NPC groups. The rates of AL were similar (11.3% vs. 9.2%, p = .414). However, the reoperation rate of patients in the PC group was significantly lower than that of patients in the NPC group after AL (36.4% vs. 11.1%, p = .025). The hospital costs were higher in the NPC leakage subgroup (p = .001). Additionally, the serum C-reactive protein levels were lower in the PC group on postoperative days (PODs) 1, 3, and 5, whereas procalcitonin levels on POD 1 and 3 were lower in the PC group but did not differ significantly on POD 5. Conclusion: Pelvic peritonization did not affect the rate of complications, especially AL; however, it effectively reduced the reoperation and inflammation rates and reduced hospitalization costs. Other short-term outcomes were similar, which warrant the increased use of pelvic peritonization in endoscopic surgery.