RESUMO
We have reported that there is a difference in the variation of the nuclear DNA content of tumor cells among cases of squamous cell carcinoma induced by 9,10-dimethyl-1,2-benzanthracene (DMBA) in the rat submandibular gland. In the present investigation, the relationship between the nuclear DNA content of tumor cells in autotransplanted sections collected from primary lesions of DMBA-induced tumors and their proliferative ability in the subfascial area of the rat abdomen was examined. As a result of autotransplantation, proliferation in the autotransplanted area was observed in 6 of 14 (42.8%) cases of autotransplantation. Five of these had a keratinizing squamous cell carcinoma while the remaining one had a sarcomatoid tumor. The histological type of the tumor of the proliferative lesion in the transplanted area was very similar to that of the tumor tissues in the primary lesion or the transplanted section collected from the primary lesions. In the proliferative group, marked variation of the nuclear DNA content was observed in the tumor cells of the transplanted section. The proliferative index (PI) was high for these tumor cells in this group. There was no variation in the nuclear DNA content in the tumor cells of the nonproliferative group, and the PI was also low. These results were considered to suggest that there was a correlation between the nuclear DNA content of these experimental tumor cell and their proliferative ability in the autotransplanted area. Therefore, the determination of nuclear DNA content by this method can be used as an objective index of the proliferative ability of tumor tissue.