Differential effect of imidazole antibiotics on untransformed and virus-transformed rat cell lines.

The imidazole antimycotics clotrimazole and miconazole were tested on untransformed rat cell line 3Y1-B clone 1-6 (3Y1) and six transformed cell lines, which were independently isolated from 3Y1 or 3Y1-B clone 1 after infection with adenovirus 12 (AD-12) or with SV40, to determine their sensitivities to these drugs. The relative plating efficiency of three cell lines (T3, W4, and W5) transformed with AD-12 was reduced to 10(-1( of the initial value by clotrimazole (2 to 4 microgram/ml), whereas that of the parental cell line 3Y1 was reduced to 10(-1) of the initial value by clotrimazole (20 to 25 microgram/ml). By contrast, the differential effect of miconazole on 3Y1 and AD-12-transformed cell lines was found to be a factor of 2. The sensitivity of the SV40-transformed 3Y1 and the AD-12-transformed cell lines. The cellular sensitivity of untransformed 3Y1 cells to clotrimazole was significantly enhanced when exposed to various doses of the unsaturated fatty acid, linoleic acid. The untransformed and transformed cell lines showed sensitivities similar to the cytocidal activity of sterol-binding antimycotics, amphotericin B and filipin.