Studies on transformation markers and tumorigenicity in segregant clones from a human hybrid line

Thirty segregant clones were back-selected in 8AG or 5BUdR media from a non-tumorigenic human intraspecific hybrid line (HeLa TK- X fibroblasts HPRT-) displaying a high plasminogen activator (PA) level, a disorganized fibronectin (FN) matrix and anchorage-independence. These clones exhibited a widely modulated expression of the above markers concomitantly with different degrees of chromosome loss. Out of six representative segregant clones tested in nude mice, two were found to re-express tumorigenicity. No significant correlation was observed between PA or FN levels and anchorage-independence, as well as between these markers and tumorigenicity.