Establishment and Characterization of High‐ and Low‐lung‐metastatic Cell Lines Derived from Murine Colon Adenocarcinoma 26 Tumor Line

We established and characterized high‐ (LuM1) and low‐lung‐metastatic (NM11) cell lines derived from murine colon adenocarcinoma 26 tumor line. LuM1 cell line was established as a clonal cell line from a cultured cell mixture derived from a lung‐metastatic nodule after 7 sequential subcutaneous transplantations of lung‐metastatic tumors in the abdominal wall of BALB/c mice. NM11 cell line was established from a cultured cell mixture derived from a subcutaneous transplant of murine colon adenocarcinoma 26 tumor cells. LuM1 cells showed marked spontaneous lung metastases, but NM11 cells rarely did. High invasive potential of LuM1 cells was revealed by in vitro invasion assay using Matrigel reconstituted membranes. Rapid retraction was observed in monolayers of human umbilical vein endothelial cells and bovine aortic endothelial cells when LuM1 cells were added on the monolayers. Gelatin zymography and immunochemical examinations with monoclonal antibodies against gelatinase B (M(r) 95,000 type IV collagenase) showed secretion of large amounts of the gelatinase by LuM1 cells.