A new cell line having the ability to metastasize to the lungs in nude mice was established from GCH-1 (human choriocarcinoma cell line). Twenty CD-1 nude mice were injected with GCH-1 cells subcutaneously. A solitary metastatic pulmonary nodule appeared in only one of these mice. The pulmonary nodule was removed and minced, and the dissociated cells obtained were transplanted subcutaneously into new mice. By repeating this process, metastatic pulmonary nodules were seen clearly to have grown in size and number by the 4th transplantation. An in vitro cell line originating in the pulmonary lesion of the 5th transplantation was designated GCH-1 (m). Pulmonary metastasis occurred in all of the mice inoculated with GCH-1 (m) grown in vitro. The doubling time of the parent line GCH-1 and its subline GCH-1 (m) was 22.6 and 36.2 hours, respectively. GCH-1 (m) cells seemed to be heterogeneous in their size and shape compared with GCH-1 cells. GCH-1 (m) secreted more hCG and beta-hCG into the culture medium than GCH-1. By the immunoperoxidase technique using poly- or monoclonal antibodies, GCH-1 (m) showed a clear positive reaction but GCH-1 was only slightly positive for hCG and beta-hCG. Both GCH-1 and GCH-1 (m) were weakly positive for HLA-A, B,C and negative for HLA-DR, SP1 and hPL. Addition of the extracts from mouse lungs to the culture medium obviously promoted the growth of GCH-1 (m) but not of GCH-1.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals Cell Line