Coordinate control of anchorage independence, actin cytoskeleton, and angiogenesis by human chromosome 1 in hamster-human hybrids.

A panel of hybrids previously derived from fusions between a chemically transformed hamster cell line and normal human fibroblasts (A. Stoler and N. Bouck, Proc. Natl. Acad. Sci. USA, 82: 570-574, 1985) has been used to test whether or not anchorage independence, lack of actin cables, and angiogenic activity, three characteristics of transformed cells considered necessary but not sufficient for neoplasia, are coordinately regulated. In these hybrids anchorage independence is initially suppressed and those hybrids where it remains suppressed have been shown to retain human chromosome 1. Here we show that suppressed hybrids also display actin microfilament cables characteristic of normal cells and are unable to elicit an angiogenic response in the rat cornea assay. In contrast, those hybrids in which anchorage independence is expressed and which have lost human chromosome 1 have an actin cytoskeleton resembling that of the transformed parent and are potently angiogenic.