Feline mammary carcinomas as a model for human breast cancer. II. Comparison of in vivo and in vitro adriamycin sensitivity.

Feline mammary carcinomas were tested for their in vitro and in vivo sensitivity to Adriamycin. In vitro, twenty randomly chosen tumor islands were studied to test the effect of concentrations of the drug ranging from 0.25-2.00 micrograms/ml. In vivo, parts of primary tumors left in situ after surgical biopsy were used to assess the response to five i.v. injections of 30 mg/m2 Adriamycin. When comparing the in vitro and in vivo response, the best sensitivity (100%) was obtained using 2.00 micrograms/ml Adriamycin and the best specificity (75%) using 1.00 microgram/ml Adriamycin, both in vitro. Tumors recurring after treatment showed acquired resistance in vitro.

Feline mammary carcinomas as a model for human breast cancer. I. Sensitivity of mammary tumor cells in culture to cytostatic drugs. A preliminary investigation of a predictive test.

Feline mammary carcinomas were found to maintain well in short-term cultures. Principally the same types of nuclear DNA frequency distribution histograms were recognized in feline mammary carcinomas as in human mammary carcinomas. However, the more abnormal histograms are less frequent in feline than in human mammary carcinomas. Feline mammary carcinomas appeared, at least in vitro, most sensitive to Doxorubicin and 5-fluorouracil. Preliminary, thymidine incorporation studies indicate both cytotoxic and cytostatic effects of Doxorubicin and 5-FU. Methotrexate was found to stimulate thymidine incorporation.

Delphinidin- and cyanidin-chlorides, promotors of cell aggregation in vitro.

Delphinidin-chloride and Cyanidinchloride cause cells in cell culture to form aggregates instead of the usual monolayers, without impairing viability or proliferation. The process is reversible.

Morphogenesis in mammary gland cell cultures. Occurrence of tubular structures in combined cultures of fibroblastic and normal epithelial cells.

In cultures with a dense confluent layer of fibroblasts mixed with a small population of normal mouse mammary epithelial cells, the latter form tubular structures that can be stimulated to secretion by hormones.

[Tissue culture investigations on the distinction between hereditary and sporadic retinoblastoma (author's transl)]. / Gewebezüchtungsuntersuchungen zur Unterscheidung des erblichen vom sporadischen Retinoblastom

The growth pattern in tissue culture of cells derived from retinoblastoma is different for all cases with known heredity and most of the cases with unknown heredity. It is concluded that those of the latter, that show a growth pattern that is identical with that of the hereditary cases, represent the hereditary cases in the group with unknown heredity.

Model approaches for evaluation of cell coupling in monolayers.

The electrical coupling of epithelial cells of the intestine of chick embryo cultured in monolayers was studied. This coupling can be evaluated by regarding the monolayer as a honeycomb structure of cells and the cells as equipotential spaces, as long as the cells are small (diameter <25µm). With help of this discrete model it was found that for the non-junctional membrane the membrane resistance isϱ m =250-2,000 Ω cm(2), and for the junctional membraneϱ m =5-50 Ω cm(2). In addition to this discrete model, a continuous model was also considered and good agreement between the two descriptions was found. With the aid of the continuous model, a value for the non-junctional membrane capacitance (C m ) was obtained: 5-50 µF/cm(2). The electrical values are not corrected for membrane folding, microvilli and the like. Tentative corrections based on electron microscopy suggest: 1,000 <ϱ m < 10,000 Ω cm(2), 10 <ϱ m < 100 Ω cm(2), 1

Representativity of human mammary tumor cell cultures: DNA-cytophotometry as a method for checking tumour cell characteristics.

Short term cultures (3-6 days) of 40 primary human mammary carcinomas were prepared and compared with the original tumours from which they were derived. As a criterion the nuclear DNA Frequency Distribution Pattern (FDP), cytophotometrically measured, was used. Comparisons were made between the FDPs of smears of freshly-cut tumour surfaces and their cultures. Twenty-nine (73%) cultures showed FDPs identical with the smears. Eleven cultures (27%) showed gross shifts in ratios between different peaks or showed a complete loss of one or more peaks in the FDP and were classified as not representative. Our results show that it is necessary to check primary mammary tumour cultures to determine whether or not they are representative of the original tumour. This is especially so if conclusions are to be drawn from the cultures about the original tumour. Analysis of FDPs in the cell islands of the cultures (migration of cells from attached clumps) resulted in a better understanding of the FDPs found in the smears. We showed that cultures of human mammary tumours either can be composed of cell islands with identical FDPs (diploid or aneuploid) or may show heterogeneity between different cell islands within one tumour.