Heterogeneity in the hormonal responsiveness of clones derived from the 13762NF @entity35 mammary XXXX .

@entity8160 @entity1420 @entity5 @entity189 @entity53 @entity37399 @entity701 @entity35 @entity420 @entity4722
The transplantable hormone-responsive @entity35 mammary @entity420 13762NF was dissociated with collagenase and hyaluronidase. Cells were cloned directly or lines were established from mass cultures and cells from these lines were cloned. Clones differed in cellular morphology, colony morphology on plastic or in collagen gel, growth rate, growth response to hormones, and hormone receptor levels. Growth response to prolactin, @entity53 , @entity1420 , @entity701 , and @entity8160 ( @entity8160 ) was determined by culturing the cells within collagen gel and using a serum-free medium base of @entity37399 (1:1) with insulin, @entity4722 , and BSA. The clones varied in their hormone responses, with all 20 of the clones tested responding to @entity701 in combination with @entity8160 . Some clones would respond to @entity8160 , @entity701 , or @entity1420 when used alone. None of the clones tested could be stimulated by prolactin or @entity53 . Receptor levels for @entity53 , @entity1420 , glucocorticoids, and @entity8160 were assessed in 3 selected clones differing in their hormone responsiveness. Receptor levels appeared to correlate with hormonal sensitivity. Selected clones transplanted into female F344 @entity35 produced @entity189 with histopathologies similar to the @entity5 .
