Genomic plasticity of the Lucké renal carcinoma: a review

The differentiation potential of the Lucké renal carcinoma of the northern leopard frog, Rana pipiens, can be characterized by the nuclear transplantation procedure. Transplantation of tumor nuclei into activated and enucleated ova results, in the best of cases, in swimming larvae which fail to feed. The larvae die in about 10 to 14 days. Rescue of tumor nuclear transplantation tadpole tissue, destined to die, has been accomplished by allografting fragments of that tissue to normal hosts. The allografts persist and differentiate a diversity of tissues which cannot be distinguished by histological analysis from allografted normal control tissue. Allografts are an imperfect mode of assay for histological competence because of the immune response of the host. Lymphocytes and eosinophils invade the grafts in about 40 days. The host immune response occurs in both experimental and control allografts. Consequently, we believe that added histogenetic potential exists in the genome of the Lucké renal carcinoma. We propose that unexpressed differentiative potential of the grafted tissue can be extracted by abrogation of the immune response of the host. A herpesvirus is the etiological agent of the Lucké renal carcinoma. We currently seek to detect viral DNA in tissue derived from tumor nuclear transplant embryos. The presence of the viral genetic material in normal mitotic progeny of Lucké tumor cells, if demonstrated, raises the question of the long-term stability of differentiated cells derived from a virus tumor. Alternatively, absence of viral DNA in the tumor nuclear transplant tissue would suggest that normal differentiation ensues after elimination of the oncogenic DNA from that tissue. Loss of viral DNA may prognosticate stable differentiation.