XXXX promotes morphological transformation of @entity329 embryo cells.

@entity4629 @entity3163 @entity5 @entity18754 @entity3014 @entity1359 @entity4515 @entity3015 @entity329 @entity7034
Sequential treatment of @entity329 embryo (SHE) cells with a chemical carcinogen followed by @entity3163 ( @entity7034 ) resulted in a higher yield of morphologically transformed cell colonies than treatment of the cells with carcinogen alone. For example, cells treated with @entity3014 ( @entity3015 ; 3 micrograms/ml) for 3 days, then with @entity7034 (25 micrograms/ml) for 4 days, exhibited a transformation frequency more than six times greater than that obtained by summing the transformation frequencies from cells treated with either @entity3015 or @entity7034 alone. This enhancement/promotion of cell transformation by @entity7034 was only expressed after the cells had been pretreated with either @entity4629 . Pretreatment of the cells with noncarcinogens or weakly-acting carcinogens or administration of @entity7034 prior to treatment with the carcinogen failed to enhance the yield of transformation. Transformation was enhanced even when the @entity7034 treatment was delayed for several days after the carcinogen treatment. However, the continued presence of @entity7034 was necessary for maintenance of the increased level of transformation. Removal of @entity7034 prior to termination of the assay resulted in a reversal of the transformed clonal morphologies to a normal phenotype such that the final yield of transformants was decreased, but was still greater than that observed after carcinogen treatment alone. A similar pattern for reversibility of the transformation enhancement also occurs for the widely recognized @entity5 promoter @entity1359 ( @entity4515 ). Seven different SHE cell pools were tested for sensitivity to @entity7034 promotion following carcinogen treatment. Although the response was heterogeneous, no carcinogen-treated cell pool was refractory to the @entity7034 -induced enhancement. A second fluorocompound, @entity18754 ( @entity18754 ), was also found to enhance carcinogen-induced cell transformation in a manner resembling that of @entity7034 .
