title: Test of recurrence after experimental radiation therapy of chemically induced autochthonous tumors in mosaic mice.
abstract: True recurrence was distinguished from induction of new second tumors after experimental radiation therapy using monoclonal tumors produced in the mosaic cell background of mice. The mice were C3H/He females heterozygous at the X-chromosome-linked locus of phosphoglycerate kinase (PGK) and consisted of two types (A and B) of somatic cells by inactivation of one of X-chromosomes. Sarcomas and carcinomas with a single PGK phenotype were produced by subcutaneous injection of 3-methylcholanthrene (MCA) into the groin of the mice, and locally and singly irradiated with 4-6.5 Krad of X rays generated by a 6 Mev linear accelerator, when they were 8-10 mm in diameter. Of 69 mice irradiated, 17 were available for comparison of the PGK and histological types of primary and recurrent tumors. Of these, 10 recurrent tumors with A-type PGK and 3 with B-type PGK exhibited the same PGK type as that of primary tumors, while one was distinguishable histologically. Only one recurrent tumor was of the opposite PGK and a different histological type from the primary tumor. Considering the probability of new tumor formation among A----A recurrent tumors, it was calculated that 79% (11/14) of the tumors that reappeared in the irradiated area were actually true recurrent tumors. Autochthonous tumors may be important in testing therapeutic methods.
mesh_terms: D000818:Animals; D005260:Female; D008748:Methylcholanthrene; D051379:Mice; D009030:Mosaicism; D009364:Neoplasm Recurrence, Local; D009374:Neoplasms, Experimental / Q000139:chemically induced / Q000235:genetics / Q000532:radiotherapy*; D010641:Phenotype; D010735:Phosphoglycerate Kinase / Q000235:genetics
chemical_list: D008748:Methylcholanthrene; D010735:Phosphoglycerate Kinase