Location of genes involved in invasion and metastasis on human chromosome 7.

We have obtained evidence for the existence of genes controlling invasion and metastasis by somatic cell fusion studies. Noninvasive, nonmetastatic mouse BW5147 T-lymphoma cells were fused with invasive human T-cells. The human cells were either activated normal peripheral blood lymphocytes or leukemic T-lymphoblasts. Both fusions resulted in highly invasive human-mouse T-cell hybrids which metastasized in nude mice. Thus the genes derived from either malignant or nonmalignant but inherently invasive cells enable the T-cell hybridomas to metastasize. By continued in vitro selection for invasive cells employing monolayers of rat embryo fibroblasts followed by subcloning, we were able to isolate invasive hybrids that had lost all human chromosomes except chromosome 7. We present evidence that one or more genes residing on human chromosome 7 are necessary and sufficient for both the establishment and maintenance of invasiveness and metastatic potential of the interspecies T-cell hybrids.