Chemotherapy-induced nuclear alterations of morphologic and genomic characteristics in a human colon cancer grafted onto nude mice.

PURPOSE: A human Dukes B colonic adenocarcinoma was grafted onto 40 nude mice. The mice were divided into four groups, one control and three representing experimental conditions. Animals in the three experimental groups received either adriamycin (ADR), 5-fluorouracil (5-FU), or camptothecin (CPT) over a 25-day period beginning 34 days after grafting. Control animals received saline on an identical schedule. Animals were killed 105 days after grafting. METHODS: The effect of therapy was assessed by three techniques: 1) tumor size was periodically measured during the life of the animals, 2) modifications of APC, Ki-ras, and p53 genes were studied by polymerase chain reaction, dot-blot analysis, restriction analysis, and DNA sequencing, and 3) image cytometry of Feulgen-stained material was used to characterize 15 parameters describing morphometric, densitometric, and textural features of tumor nuclei. RESULTS: When compared with controls, tumor growth (size) was maximally suppressed by treatment with CPT (P < or = 0.001). Growth was inhibited significantly by treatment with 5-FU (P < or = 0.01); no statistical difference in tumor size was observed between controls and animals treated with ADR. Modifications of APC, Ki-ras, and p53 genes were not observed; however, treatment did inhibit amplification of APC and p53 genes. CONCLUSIONS: The 15 morphonuclear parameters were assessed to define populations of cell nuclei altered by chemotherapy. Although CPT maximally suppressed growth, it did not alter nuclear morphology when compared with controls. Treatment with either 5-FU or ADR resulted in nuclear morphologic alterations defined as distinct populations using multivariate analysis. Nonsupervised linear discriminant analysis was used to quantify the relative proportions of these populations. Four morphonuclear parameters were identified, which discriminated nuclei exposed to either ADR or 5-FU from controls.

Characterization of the hormone-sensitivity of three human non-small-cell lung cancers grafted onto nude mice.

The in vivo hormone sensitivity of three human NSCLCs grafted onto female nude mice (labelled KLX7, KLX9 and KLX14) was characterized on a dynamic level, i.e. on the level of both the macroscopic growth and the proliferative fraction (PF = percentage of cells in the S+G2+M Fractions). Two sets of experiments were performed. The first set showed the influence on the macroscopic growth of the NSCLC xenograft of castration performed either before or after tumor grafting. The second set showed the influence of a pulse of 6 different hormones or growth factors on the PF index magnitude recorded 36 h after their administration to the xenograft-bearing mice. These 6 hormones or growth factors were EGF, estradiol-17-beta (E2), gastrin (G), platelet-derived growth factor (PDGF), basic fibroblast growth factor (bFGF) and bombesin (B). The results show that the KLX7 model grew definitely faster on the nude mice than the other two models. Ovariectomy before or after tumor grafting did not significantly modify the growth pattern of the KLX7 model, while castration before tumor grafting significantly increased the macroscopic growth of both the KLX9 and the KLX14 tumors. In contrast, E2, bFGF, G and B significantly increased the proliferative activity of the KLX7 model 36 h after their administration to the tumor-bearing mice while remaining without any apparent statistically significant effects in both the KLX9 and the KLX14 models.

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.