[Capacity for differentiation and normalization of tumor cell populations in transplantation into the anterior chamber of the eye. III. Rhabdomyosarcoma A-7 clones].

Four clone lines of transplantable cell polymorphic rhabdomyosarcoma A-7 were investigated during transplantation to the subcutaneous connective tissue (SCT) and into eye anterior chamber (EAC). Cell morphology of transplants was studied by light and electron microscopy, the activity of their LDH M- and H-subunits was examined cytochemically, and the quantity of their nuclear DNA--cytophotometrically. In the case of A-7/1, A-7/2 and A-7/3 cell lines of EAC transplants we noticed a decrease in cell element kataplasia levels, differences in LDH M- and H-form ratio, reduction in the karyotype variability. Transplants of A-7/4 clone line were similar in SCT and EAC for all the signs studied. The results obtained show that the transplantable cell polymorphic rhabdomyosarcoma A-7 is heterogeneous for its differentiation and normalizing capacities during EAC proliferation. The data reported elsewhere concerning capability of four lines of murine rhabdomyosarcomas to normalize in EAC are discussed, and some possible mechanisms of this effect are regarded.