アクティブボード・２０１４年１０月
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研究発表を行った学会；
・第７３回日本癌学会学術総会
　２０１４年　９月２５日〜２７日（横浜）
タイトル；Therapy of liver metastasis of gastric cancer by iPS-ML in a xenograft model.
発表者；匂坂　正孝　氏
　　　（熊本大学　大学院生命科学研究部　免疫識別学分野、小児外科・移植外科学分野）
Abstract；
Surgical therapy cannot be adopted for the patients of gastric cancer with multiple liver metastasis or peritoneal dissemination, and the treatment outcome would be unfavorable. Disease control by chemotherapy is also difficult in most cases. To improve the situation, we are developing cellular therapy based on iPS cell technology. We have developed a method to generate myeloid cells with proliferation capacity from human iPS cells, and designated them iPS-ML (iPS-cell–derived myeloid/macrophage line). Previously, we demonstrated therapeutic effect of iPS-ML expressing IFN-β (iPS-ML/IFN-β) against peritoneal dissemination of gastric cancer and pancreatic cancer by using xenograft models. In the current study, we evaluated the application of iPS-ML to therapy of liver metastasis of gastric cancer. We established a model of liver metastasis of gastric cancer by intra-splenic injection of human gastric cancer cell line MKN-45 expressing firefly luciferase into SCID mice. When iPS-ML were injected intraperitoneally into the mice with pre-established liver metastatic lesion, iPS-ML distributed mainly in peritoneum and mesenterium, and also some into liver. Treatment with iPS-ML/IFN-β significantly inhibited the growth liver metastatic lesions of the gastric cancer. Because massive infiltration of iPS-ML into the liver was not observed, we currently consider that IFN-β produced by iPS-ML/IFN-β distributed in the peritoneal cavity was transported to the liver via portal vein and exhibited the therapeutic effect against hepatic lesions.