Differential effects of abrin on normal and tumor cells

✍ Scribed by Lee-Nien Lillian Chan; Jiann-Shyong Li; Su-Yin Liu

• Publisher: John Wiley and Sons
• Year: 1985
• Tongue: English
• Weight: 855 KB
• Volume: 123
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1041230119

✦ Synopsis

The effects of the plant toxin abrin on normal mouse embryonic fibroblasts (MEF), an untransformed mouse cell line (NIH 3T3), and two mouse tumor cell lines (LMTK-and S-180) were studied. Measurements of cell growth and colony formation showed that MEF and S-180 cells were more sensitive to abrin intoxication than NIH 3T3 and LMTK-cells. Also, the effects of abrin on the inhibition of ['Hlleucine and [3H]thymidine incorporation were more evident in MEF and S-180 cells. The basis for these varying responses to abrin by the four different cells was examined. The number of abrin binding sites per cell was determined from ['251]abrin binding studies: NIH 3T3 and LMTKcells had si nificantly fewer abrin binding sites than MEF and S-180 cells. The fate of the f251jabrin after internalization was examined by gel electrophoresis and autoradiography. A pattern of time-dependent degradation was observed, degradation being more rapid in NIH 3T3 and S-180 cells than in LMTK-and MEF cells. We conclude that the varying responses of different cells to the toxin abrin may be due to several factors, including the relative number of abrin binding sites on the cell surface and the rate of degradation of the toxin once internalized. The results also show that the sensitivities of the cells to abrin do not necessarily correlate with their normal or neoplastic state.

Cells

Cells were grown in Dulbecco's modified Eagle's medium (DMEM) (Grand Island Biological Co., Grand Island, NY) with 10% fetal calf serum at 37°C under lo%, COz. NIH 3T3 cells were obtained from Dr.