X-linked dominant growth suppression of transplanted tumors in C57BL/6J-scid mice

Tumor susceptibility, angiogenesis, and immune response differ between mouse strains. We, therefore, examined the growth rates of tumor xenografts in three genetically isolated strains of severe combined immunodeficient mice (C.B-17, C57BL/6J, and C3H). Tumors grew at significantly reduced rates in the C57BL/6J-scid strain. Engrafting bone marrow from the C57BL/6J-scid strain onto C.B-17-scid mice did not transfer the slow-growing tumor phenotype to the recipient mice; this counters the supposition that the slow-growing tumor phenotype is caused by a greater immune response to the xenograft in the C57BL/6J-scid strain. To establish the inheritance pattern of the slow-growing tumor phenotype, we reciprocally crossed C.B-17-scid mice and C57BL/6J-scid mice. Tumor growth was suppressed in all of the F₁ progeny except the male mice derived from the cross between C.B-17-scid female and C57BL/6J-scid male mice. The F₁ male mice that received the X chromosome from the C.B-17 strain displayed a fast-growing tumor phenotype. These results confirm that there are significant strain differences in capacity to support the growth of tumor xenografts. In addition, these results reveal the existence of a dominant allele involved in host suppression of tumor growth on the X chromosome of C57BL/ 6J mice.