Susceptibility of BALB/cGnDu mice to transplantable tumors, in vitro transformed cells, BK and SV40 viruses, and chemical carcinogens

Various oncogenic agents were employed in tumor susceptibility studies of an inbred subline of BALB/cGn mice, BALB/cGnDu, which carries a mutant gene that results in spontaneous thymic involution in homozygous recessive individuals. Of 18 transplantable tumors, 3 in vitro transformed cell lines, 2 oncogenic papovaviruses and 3 chemical carcinogens evaluated, only the Harding-Passey amelanotic melanoma produced tumors in 100% of the normal adult mice injected. The S180 pleomorphic sarcoma produced tumors in 56% of normal adult mice. Although not tumorigenic in adults, the mKSA, Morris (rat) hepatoma No. 7777, and a human papovavirus – transformed human cell induced mouse tumor line [GIllO(BK) B6D2 Tu] formed tumors in 100, 62 and 70%, respectively, of recipients inoculated as neonates. SV40 and human papovavirus BK virions, as well as SV40, BK, and spontaneous in vitro transformed BALB/cGnDu cells were not tumorigenic. Although the histocompatibility antigens of these animals have not been studied, no correlations could be made between the tumor susceptibility of these animals with regard to the commonly employed inbred line BALB/c nor with regard to the range of host susceptibility of the transplantable tumors. This inbred subline represents a new strain of mice whose genetic defect makes it useful for transplantation immunology and physiological genetics.