The use of nuclear-DNA content to monitor the chemosensitivity of human non-small-cell-lung (nsclc) and colorectal cancers xenografted onto nude-mice.

: The chemosensitivity of human lung and colorectal tumours grafted onto nude mice was assessed at the individual tumour-bearing mouse level. The results show that various pieces of a given tumour grafted onto a number of animals exhibit different profiles of sensitivity to the same chemotherapy. We used the nuclear DNA content to subtype the clonal tumour heterogeneity of these models. This monitoring was performed by means of the digital cell image analysis of Feulgen-stained nuclei. The data show that the nuclear DNA content of human lung and colorectal models vanes markedly not only over serial transplantations onto animals on the one hand, but also within one and the same xenografted tumour during its spontaneous growth on the other. Such nuclear DNA content variations might explain the variability of the chemosensitivity within a given human xenograft model.