Syrian hamster cells colony

Transformation of Syrian Hamster Cells by Metals. When cultures of cells were exposed to two nickel compounds with different carcinogenic potencies, there were differences in the incidence of transformed colonies that formed (Table II). Treatment with amorphous NiS resulted in a low incidence of transformation while treatment with crystalline NiaS2 induced the appearance of numerous transformed colonies (Table II). In this series of experiments, control cultures had no transformed colonies however, in some experiments there was an occasional incidence of spontaneous transformation. The induction of transformation by... 

Carcinogenic metal compoimds such as crystalline Ni3S2 induced a dose-dependent statistically significant incidence of transformation in secondary cultures of Syrian hamster cells. A chemically related compound, amorphous NiS, which is not carcinogenic, resulted in no statistically significant incidences of transformed colonies. Untreated control cultures also had no statistically significant incidence of transformation. We have... 

Mettang, T, Thomas, S., Kiefer, T, Fischer, F.-R, Kuhlmann, U., Wodarz, R. Rettenmeier, A.W. (1996b) Uraemic praritus and exposure to di(2-ethylhexyl) phthalate (DEHP) in haemodialysis patients. Nephrol. Dial. Transplant., 11, 2439-2443 Mikalsen, S.-O. Saimer, T. (1993) Intercellular communication in colonies of Syrian hamster embryo cells and the susceptibility for morphological transformation. Carcinogenesis, 14, 251-257... 

No morphologically transformed colonies were observed in Syrian hamster embryo cell cultures, either after treatment in vitro or after exposure of the dams to dimethylformamide (3 mL/kg bw) by intraperitoneal injection. 

No morphologically transformed colonies were seen in control cultures. Cells transformed in this way also exhibited the ability to grow in soft agar and formed anaplastic fibrosarcomas when transplanted into the cheek pouches of four-week old male hamsters (J5 0. Tsuda et l. (33) also demonstrated morphological transformation in primary cultures of Syrian hamster embryo cells by crude tryptophan pyrolysates. In this experiment, a concentration of 50 pg/ml of pyrolysate induced 1.8% transformed colonies. The control transformation frequency was 0.028%. 

Figure 1, Lightly packed (left) and densely packed (right) normal Syrian hamster fetal cells. Cultures of Syrian hamster fetal cells were obtained from minced whole embryos by trypsin treatment (see Methods for details). These cultures were untreated in parallel with cultures exposed to various carcinogens. The cultures were washed and the cells replated to form colonies in fresh medium. Following two weeks of incubation the cultures were fixed and stained with a crystal violet solution. Note the orderly growth of normal cells in the...

Figure 4, A tightly packed, piled-up normal Syrian hamster fetal cell colony. Treatment with some of the metal carcinogens induced a higher incidence of these tightly packed/piled up normal colonies. This type of colony was also present in untreated cultures.

Third passage log phase cultures of Syrian hamster fetal cells were treated as described in the table. Cultures treated with benzopyrene and Ni3S2 were exposed to benzopyrene for 24 h prior to treatment with the metal. Cultures were treated with the metal compounds three times using a two-day exposure for each treatment. Cells were then removed from the plate by trypsini-zation and the number of cells present in each plate was determined with a hemocytometer. Five thousand or ten thousand cells were replated to form colonies into 100 mm diameter plates and the number of surviving colonies in each plate was counted. Each number shown in the table is the mean of four tissue culture plates. 

Cell Survival Determinations. Immediately after exposure to X-rays, UV light, or alkylating agents, cells were either allowed to grow with or without 3AB (1 vaM) for mutation or transformation expression, or diluted to low density and inoculated into Petri dishes for colony formation. Colonies were left to grow for 8 days (CHO cells), 10 days (Syrian hamster ovary cells), or 6 weeks (C3H lOTl/2 cells) before fixation. 

Although not necessarily a genotoxic event, in vitro cell transformation is included in this section. The basic fraction of a tryptophan pyrolysate and synthetic Trp-P-1 and Trp-P-2 were tested for transforming activity in Syrian golden hamster embryo cells (37). The percent of morphologically transformed colonies was 1.5, 1.3 and 0.54 for Trp-P-2, Trp-P-1 and 3-methyl-cholanthrene (3MC), respectively. The optimum concentrations for Trp-P-1 and Trp-P-2 were 0.5 pg/ml versus 1.0 pg/ml for 3MC. 

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