Effect of 2-acetylaminofluorene on the binding of epidermal growth factor to microsomal and Golgi fractions of rat liver cells

The livers of rats fed the hepatocarcinogen 2-acetylaminofluorene (0.02%) with chow showed a sharp decrease in the binding of epidermal growth factor to microsomes and Golgi fractions. The binding to the latter decreased from 15.3% specific binding per 0.1 mg protein in controls to 9.4% after 2 days and reached a nadir of 0.8% after 21 days. The binding to microsomes decreased from 26.3% specific binding per 0.5 mg protein in the controls to 17.4% after 4 days and reached a nadir of 7.5% after 46 days. The low binding which persisted until the end of the experiment (85 days) was due to the apparent decrease in the number of receptors without significant changes in their affinity. Also, there was only partial recovery in rats fed 2-acetylaminofluorene for 90 to 107 days and taken off the carcinogen for 30 to 75 days. In vitro, neither 2-acetylaminofluorene nor its metabolites hydroxy- and acetocy -2-acetylaminofluorene significantly decreased epidermal growth factor binding to the isolated microsomal fraction.

Cell surface-mediated cytotoxicity of polymer-bound Adriamycin against drug-resistant hepatocytes

Growth inhibition properties of Adriamycin-coupled polyglutaraldehyde microspheres have been assessed using a highly resistant rat liver cell line, RLC. Covalent attachment of Adriamycin to microspheres increased the cytostatic activity of the drug 1000-fold for this cell line as measured by 50% inhibitory concentration determinations. The effects of Adriamycin-polymer complexes were investigated and compared to free drug, using trypan blue dye exclusion and 51Cr release as indicators of cell viability. When carcinogen-altered drug-resistant rat hepatocytes were tested at an Adriamycin concentration of 10(-6) M, the polymer-bound drug killed 32% of the cells, while the free drug had no detectable cytotoxic effect. However, with normal rat hepatocytes at the same drug concentration, the Adriamycin-coupled microspheres were shown to be less toxic than free drug at 24 hr. It was demonstrated that greater than 99.5% of the drug remains covalently coupled to the microspheres throughout the experiments. Scanning electron micrographs are presented for both cell types, which demonstrate the effects of free and bound Adriamycin on the ultrastructure of the cell surface. The cells lose their microvilli, exhibit numerous blebs, and develop holes and pits in the surface. Transmission electron microscopy demonstrates that less than 1% of the microspheres is internalized by either cell type. Multiple interactions of the drug-polymer complexes with the cell surface are presented as the most probable explanation for the results.

Renal carcinoma manifesting as breast mass

A patient is described who initially presented with Stage I breast carcinoma and then with a T2, N0, M0 carcinoma of a kidney with moderately well-differentiated clear-cell features. Five years later, a contralateral breast mass developed which was histologically identical with renal primary tumor. Breast metastasis from renal primary carcinoma has been noted in the literature in 6 other cases, although this is only the third actual case report. This is the first case report of such a bizarre progression of disease. This patient is currently well, without clinically detectable tumor and illustrates the variable nature of metastatic renal cancer. The literature on renal cancer metastasizing to the breast is reviewed.

Continuous five-day infusion of PALA and 5FU: a pilot phase II trial

In order to determine whether a simultaneous infusion of N-(phospho-n-acetyl)-L-aspartic acid (PALA) was able to increase the rate of antitumor response to 5-fluorouracil (5-FU), a pilot study was conducted. Of 10 evaluable patients with previously drug-untreated colorectal carcinoma, there were only two partial responses, lasting 2.3 and 1.6 months. No partial responses were observed in three evaluable patients with soft tissue sarcomas. The dose-limiting toxicity was dermatitis. The simultaneous infusion of PALA and 5-FU is not likely to produce a high number of antitumor responses of long duration in patients with colorectal carcinoma.

Resistance to the cytocidal effects of adriamycin is an early phenotypic change induced during hepatocarcinogenesis

Resistance to the cytocidal action of Adriamycin (ADR) was induced in rat hepatocytes by incorporation of the carcinogen 2-acetylaminofluorene (AAF) into the rat diet. Using a quantitative assay in primary monolayer culture, it was demonstrated that resistance to ADR is an early phenotypic change that is induced during chemical carcinogenesis in the rat, and appears to be stable.

The variable transformation in metastases from testicular germ cell tumors: the need for selective biopsy

The propensity for metastatic testicular teratocarcinoma to undergo differentiation, particularly when associated with successful cancer chemotherapy, means that the histology of residual disease following chemotherapy cannot be assumed without biopsy. We present 4 cases in which biopsy of a metastasis was important in determining the management of the patient. We conclude that because of the variable nature of the transformation of metastases in testicular germ cell tumors, particularly after chemotherapy, residual disease will often need further biopsy to establish whether it represents residual malignant disease or benign transformation.

Carcinogen-induced drug resistance in rat hepatocytes

The relative resistance of liver cells in primary monolayer cell culture to the cytocidal effects of methotrexate, Adriamycin, cycloheximide, or aflatoxin B1 was studied using cells derived from normal rats, rats subjected to two-thirds hepatectomy, or rat fed dietary carcinogen. Normal rat liver cells were highly sensitive to the toxic effects of methotrexate. Adriamycin, cycloheximide, and aflatoxin B1. In contrast, liver cells from carcinogen-treated rats were resistant to the toxic effects of these agents. Cells derived from rats at 24 hr post two-thirds hepatectomy were sensitive to Adriamycin but not to cycloheximide or aflatoxin B1.

Antiemetic effect of intravenous diazepam in patients receiving cis-diamminedichloroplatinum II: a pilot study

A pilot study suggesting the usefulness of intravenous diazepam as an antiemetic for adult patients receiving cis-diamminedichloroplatinum is presented. Observations included 24 patients and 34 courses of therapy. Patients received diazepam and prochlorperazine, and the incidence of vomiting and subjective evaluation of nausea were compared to previous courses of therapy with prochlorperazine alone. A positive response was observed in 87% of the patients. Use of other antiemetics is briefly reviewed.