[Capacity for differentiation and normalization of tumor cell populations transplanted into the anterior chamber of the eye. II. Changes in metastasizing polymorphonuclear rhabdomyosarcoma].

Polymorphic CC57W mice rhabdomyosarcoma MC-53, after selection for malignancy, was investigated during the transplantation to subcutaneous connective tissue (SCT) and the eye anterior chamber (EAC). SCT and EAC transplants appeared to be equal both morphologically and ultrastructurally. Relationship between M- and H-forms of LDH, and the karyotype structure of tumor cell populations were invariably similar in SCT and EAC. However, after EAC proliferation, in contrast to SCT proliferation, transplantability of tumor rhabdomyoblasts decreased, which may be associated with a decrease in proliferative activity of tumor cells in the EAC. Our data allow to suppose that mouse rhabdomyosarcoma MC-53 cells, during selection for malignancy, lost its capacity of differentiating and normalizing in EAC, unlike the previously investigated rhabdomyosarcomas MC-62, MC-III and A-7. These results may be explained by the fast progression of this tumor line. It is obvious that capacity of tumor cells of differentiating and normalizing during the EAC proliferation may depend on the tumor histological type, on the retention capacity of tumor cell elements of differentiating and on the stage of progression.