ICAM‐1 (Intercellular Adhesion Molecule‐1) Gene Transfection Inhibits Lymph Node Metastasis by Human Gastric Cancer Cells

Lymph node metastasis is one of the prognostic factors in gastric cancer. We have previously reported that decreased intercellular adhesion molecule‐1 (ICAM‐1) expression on cancer cells is associated with lymph node metastasis using a gastric cancer cell. In this study, we transfected ICAM‐1 gene into a gastric cancer cell line, 2MLN, and analyzed the effect on lymph node metastasis in vitro and in vivo. A significantly greater amount of peripheral blood mononuclear cells (PBMC) adhered to ICAM‐1 transfected 2MLN cells, 2MLN/ICAM cells, than to 2MLN/Vector cells. The lysis of 2MLN/ICAM cells by PBMC was significantly increased compared with that of 2MLN/Vector cells. The tumor growth rate of 2MLN/ICAM cells was significantly decreased in vivo. Lymph node metastases caused by 2MLN/ICAM cells were recognized as being fewer in number and smaller, while many lymph node metastases were caused by 2MLN cells. Histologic findings showed that leukocytes were heavily infiltrated in both the 2MLN/ICAM tumors and metastatic lesions, while only a few leukocytes were observed in the lesions associated with 2MLN cells. The above findings indicate that ICAM‐1 gene transduction could prove to be an effective gene therapy for lymph node metastasis of gastric cancer.