[Capacity for differentiation and normalization of populations of tumor cells transplanted into the anterior chamber of the eye. I. Changes in the pleomorphic rhabdomyosarcomas MKh-III and A-7 of mice].

Tumors transplanted into the eye anterior chamber (EAC) were atypic, more differentiated morphologically and with higher activity of H-forms of LDH, compared to the same tumors grown in the subcutaneous connective tissue (SCT). Besides, in the EAC, the tumors were less karyotypically heterogeneous and had lesser mitotic indices, than in the SCT. After cultivation in the EAC, populations of tumor rhabdomyoblasts displayed a decreased transplantability in SCT, i.e. the usual site of their implantation. These results may suggest that the proliferation of tumor cell populations in the EAC, i.e. in the immunologically privileged place, can be accompanied by the reducing of their malignancy up to the total loss of the common tumorigenic ability. Even the cell populations of tumor rhabdomyoblasts from the late stages of tumor progression can undergo such a process of normalization.