Human chromosome II inhibits tumorigenicity of a murine squamous cell carcinoma cell line

Loss of heterozygosity (LOH) of mouse chromosome 7 has been consistently demonstrated in chemically induced murine squamous cell carcinomas (SCCs). The region of this chromosome presenting LOH in the mouse tumors is syntenic to human chromosome segments II p I5 and II q. To determine whether the introduction of human chromosome (Hchr) II can suppress the growth of murine SCC, we injected four clones of a chemically induced murine SCC cell line bearing an Hchr II into athymic BALB/c nude mice. All microcell hybrid clones with Hchr II (CH721Hchr II) had latency periods twice as long as those of the parental CH72 cells and control hybrids containing a Hchr 12. Tumor‐derived cells from CH721Hchr II hybrids had lost centromeric and telomeric sequences from Hchr II. All repressed cell lines grew significantly m e slowly in vitro than did the controls. These results suggest that Hchr II contains a tumor‐suppressor gene capable of inhibiting tumorigenicity in chemically induced SCC, confirming common pathways in the development of human neoplasias and the murine model. © 1995 Wiley‐Liss, Inc.