A sequential, quantitative loss of Peanut agglutinin (PNA) binding with progression of mouse mammary cells from normal to preneoplastic to neoplastic phenotypes was observed. Normal mammary epithelium, preneoplastic mammary lesions designated D2HAN (D2-type hyperplastic alveolar nodules) and a series of nine spontaneous tumours (D2ST1, D2ST2, D2ST3, D2ST4,… (More)
Four transplantable tumors, three (66, 410, and 168cl) isolated from a spontaneously occurring strain BALB/cfC3H mammary tumor and one (D2) arising from a BALB/c hyperplastic alveolar nodule were found to grow better in mammary fatpads than at s.c. sites. Furthermore, tumor growth was better (p less than 0.05) in intact mammary glands than in cleared… (More)
In order to quantitate the effects of tumour subpopulation interactions, we have devised a method to determine the subpopulation composition of tumours by using paired tumour cell lines able to grow in different selective media. Line 4T07 forms colonies in thioguanine but not in HAT and line 168 forms colonies in HAT but not in thioguanine. An independent… (More)
In order to examine in detail the sensitivity to chemotherapy of tumour cells at various organ sites and at various stages of metastasis, we have used a series of cell lines, all selected from sister subpopulations derived from a single mouse mammary tumour, which can be distinguished and quantitated from normal cells and from each other through growth in… (More)
Mixtures of drug-resistant and drug-sensitive tumour cells growing in 3-dimensional boluses in collagen gel matrix are shown to be effectively coupled so that the response of the mixture is significantly influenced by a subpopulation making up only 1% of the total cells.