agar and Carcinoma--Ehrlich-Tumor

The effects of pretreatment growth conditions on the sensitivity of tumor cells to various cytotoxic agents were investigated using murine Ehrlich ascites tumor cells grown in two different environments. The tumor cells adapted to grow in the peritoneal cavity of mice were found to be more sensitive to ionizing radiation, oxygen toxicity, doxorubicin, and bleomycin than tumor cells adapted to grow in vitro. However, there was no difference in their sensitivity to 5-fluorouracil. One obvious difference between these two growth environments is oxygen tension; it is between 2.6 and 5.2% (20-40 mmHg) for the peritoneal cavity and 21% (159 mmHg) for the regular tissue culture. To investigate the role of oxygen tension, tumor cells from the peritoneal cavity were grown in tissue culture having either 21% O2 or 4% O2 in the gas phase. Within 4 d, tumor cells that were exposed to 21% O2, but not to 4% O2, in vitro gradually became as resistant to cytotoxic agents as the tumor cells continuously cultured in vitro under 21% O2. It appears that the adaptation of tumor cells to different environments having different partial pressure of oxygen alters their sensitivity not only to oxygen toxicity but also to other cytotoxic agents that damage or kill cells by generating free radicals.

Topics: Agar; Animals; Antibiotics, Antineoplastic; Antineoplastic Agents; Antioxidants; Bleomycin; Carcinoma, Ehrlich Tumor; Cell Division; Cell Survival; Dose-Response Relationship, Drug; Dose-Response Relationship, Radiation; Doxorubicin; Female; Fluorouracil; Free Radicals; Glutathione; Mice; Neoplasms; Oxygen; Radiation, Ionizing; Sensitivity and Specificity; Superoxide Dismutase; Time Factors

Thermosensitivity of clonogenic ascites Ehrlich carcinoma cells (AEC), forming colonies in agar cultures in diffusion chambers was studied when heating them in vitro at 41-44 degrees C. The clonogenic cells of AEC are shown not to essentially differ both in the colony-forming efficiency (CFE) and in the proliferative status on the 3rd and 7th days. No essential differences are revealed in thermosensitivity of such cells. The heating time-survival curves are exponential or S-shaped with a small "shoulder". The temperature increase by 1 degree C resulted in a 2-2.5-fold decrease in the time of effective hyperthermia treatment. The values of D0 for cells treated with 42 degrees C in different experiments varied from 20.1 min to 24.6 min. Only one type of thermal damage reaction with the energy of inactivation about 150 kcal/M was observed in AEC cells in the temperature range studied.

Topics: Agar; Animals; Carcinoma, Ehrlich Tumor; Cells, Cultured; DNA, Neoplasm; Hot Temperature; Mice; Mice, Inbred C57BL; Mice, Inbred CBA; Neoplasm Transplantation; Neoplastic Stem Cells; Temperature; Time Factors

A simple technique for maintaining low oxygen concentrations (0.1-20%) is described. These conditions were then used to study the effect of oxygen on colony growth of neoplastic cells in soft-agar. Physiologically low oxygen concentrations (0.1-10%) compared to 20% O2 were found to enhance plating efficiency and colony size of tumour cells. The optimal oxygen concentration for plating efficiency varied with tumour studied and may be as low as 0.1%. Having established that tumour cell colonies will grow better at 0.1-10% O2 compared to 20% O2, the mechanism by which this enhancement occurs was investigated. Observations on the effect of free radical scavengers and superoxide dismutase on plating efficiency of Ehrlich's ascites tumour cells suggests that this phenomenon occurs through oxygen toxicity mediated by superoxide anion.

Topics: Agar; Animals; Carcinoma, Ehrlich Tumor; Cell Division; Cell Survival; Cells, Cultured; Ditiocarb; Dose-Response Relationship, Drug; Free Radicals; Humans; Mice; Mice, Inbred ICR; Neoplasm Transplantation; Neoplastic Stem Cells; Oxygen; Stem Cells; Superoxide Dismutase; Transplantation, Heterologous

Topics: Adenosine Triphosphate; Agar; Animals; Carcinoma, Ehrlich Tumor; Cell Fractionation; Cell Nucleus; Cytosine Nucleotides; Deoxyribonucleases; DNA; Electrophoresis; Guanosine Triphosphate; Hot Temperature; Liver; Male; Methods; Mice; Phenols; Phosphorus Isotopes; Rats; RNA; RNA, Ribosomal; Uracil Nucleotides

Topics: Acrylamides; Acrylates; Agar; Animals; Carcinoma, Ehrlich Tumor; Cell Line; Cells, Cultured; Cricetinae; Electrophoresis, Disc; Gels; Kidney; Methods; RNA

Topics: Abnormalities, Drug-Induced; Abortion, Spontaneous; Agar; Animals; Anti-Bacterial Agents; Antineoplastic Agents; Carcinoma, Ehrlich Tumor; Carrageenan; Enterobacteriaceae; Female; Fetal Death; Gestational Age; Injections, Intraperitoneal; Injections, Subcutaneous; Mice; Pregnancy; Resins, Plant; Sterilization; Talc; Uterus

Topics: Agar; Animals; Antibiotics, Antineoplastic; Antiviral Agents; Ascomycota; Carcinoma, Ehrlich Tumor; Chromatography; Diffusion; Fibroblasts; HeLa Cells; Magnetic Resonance Spectroscopy; Methods; Mice; Newcastle disease virus; Simplexvirus; Spectrum Analysis

Topics: Agar; Animals; Antibiotics, Antineoplastic; Antiviral Agents; Bacillus subtilis; Carcinoma, Ehrlich Tumor; Chickens; Crystallization; Diffusion; Embryo, Mammalian; Embryo, Nonmammalian; Fibroblasts; Mice; Newcastle disease virus; Proteus; Shigella; Spectrum Analysis; Staphylococcus

Topics: Agar; Animals; Carcinoma, Ehrlich Tumor; Chromatography; DNA; Electrophoresis; Formaldehyde; Gels; Hydrogen-Ion Concentration; Liver; Methylation; Mice; Nucleic Acids; Phosphorus Isotopes; RNA; RNA, Neoplasm; RNA, Transfer; Serum Albumin; Spectrophotometry; Ultraviolet Rays

Topics: Agar; Animals; Antineoplastic Agents; Carcinoma; Carcinoma, Ehrlich Tumor; Chemistry, Pharmaceutical; Enzyme Inhibitors; Mice; Oxidoreductases; Pharmacology; Research; Sarcoma 180; Sarcoma, Yoshida