Department of Gastrointestinal Surgery, Jichi Medical University, Shimotsuke, Japan.
Department of Gastrointestinal Surgery, The University of Tokyo, Tokyo, Japan.
Sci Rep. 2018 Jan 12;8(1):632. doi: 10.1038/s41598-017-19091-2.
Many types of immune cells appear in peritoneal cavity after abdominal surgery. In patients who underwent laparotomy due to gastric cancer, peritoneal lavages were obtained before and after surgical procedure. Cells were recovered from intermediate layer after Ficoll-Hypaque centrifugation and analyzed for phenotypes and functions, especially focused on low density neutrophils (LDN). The number of CD66b (+) LDN with mature phenotype was markedly elevated in postoperative as compared with preoperative lavages. Short term culture of the purified LDN produced many threadlike structures positive for SYTOX, nucleic acid staining, as well as histone and myeloperoxidase, suggesting the NETs formation. Human gastric cancer cells, MKN45, OCUM-1 and NUGC-4, were selectively attached on the NETs, which was totally abolished by the pretreatment of DNAse I. Intraperitoneal (IP) co-transfer of the LDN with MKN45 in nude mice strongly augments the metastasis formation on peritoneum, which was strongly suppressed by the following IP administration of DNAse I. Many NETs-like structures were detected on the surface of human omental tissue resected by gastrectomy. NETs on peritoneal surface can assist the clustering and growth of free tumor cells disseminated in abdomen. Disruption of the NETs by DNAse might be useful to prevent the peritoneal recurrence after abdominal surgery.
术后腹腔内会出现多种免疫细胞。在因胃癌而行剖腹手术的患者中，在手术前后进行了腹腔灌洗。用菲可（Ficoll）-泛影葡胺（Hypaque）梯度离心法从中间层回收细胞，并分析其表型和功能，尤其关注低密度中性粒细胞（LDN）。与术前灌洗相比，术后灌洗中具有成熟表型的 CD66b（+）LDN 数量明显升高。纯化的 LDN 短期培养后会产生许多丝状结构，SYTOX、核酸染色、组蛋白和髓过氧化物酶均呈阳性，提示 NET 形成。人胃癌细胞 MKN45、OCUM-1 和 NUGC-4 选择性附着在 NETs 上，用 DNAse I 预处理可完全消除这种附着。裸鼠腹腔内共转染 LDN 和 MKN45 可强烈增强胃癌细胞在腹膜上的转移形成，用 DNAse I 腹腔内给药可强烈抑制这种转移形成。在胃癌患者的大网膜组织切除标本中也检测到许多 NETs 样结构。腹膜表面的 NETs 可协助游离肿瘤细胞在腹部的聚集和生长。用 DNAse 破坏 NETs 可能有助于预防腹部手术后的腹膜复发。
