Factors influencing expression of mammary ductal dysplasia in cell dissociation-derived murine mammary outgrowths
The present study was designed to examine this cell dose effect further and to determine if the developmental state of the outgrowths or the time between carcinogen administration and cell dissociation affects the expression and persistence of the ductal dysplasias. Mammary outgrowths were derived by injecting 10(4) or 10(5) enzymatically dissociated mammary cells into gland-free fat pads of 3-week-old female BALB/c mice. Donor animals were untreated or were exposed to either 7,12-dimethylbenz(a)anthracene or gamma-ray irradiation. The outgrowths were examined at 4.5, 8, 10, or 16 weeks after transplantation, depending on the experiment, and classified as having normal or dysplastic growth. The data indicated that expression of ductal dysplasia was greater in outgrowths derived from 10(4) than from 10(5) cells regardless of the developmental state of the outgrowths. When 24 hr elapsed between carcinogen exposure and cell dissociation, expression of lesions in outgrowths derived from 10(4) cells required active ductal growth, in that lesions that were present in developing outgrowths remodeled and were no longer detectable when the outgrowths completely filled the fat pad. When second-transplant-generation outgrowths were derived from cells of full (non-growing) first-generation outgrowths, ductal dysplasias were reexpressed but, once again, only within developing outgrowths. Increasing the time between carcinogen treatment and cell dissociation, i.e., 6 days or longer, resulted in both increased frequencies of ductal dysplasias and substantial numbers of lesions which persisted within full outgrowths. These results suggested that the acquisition of the altered growth potential which resulted in ductal dysplasias and the ability of these lesions to gain some autonomy from growth-regulatory mechanisms were separate events that occurred at different times after carcinogen treatment.
- Research Organization:
- Michigan Cancer Foundation, Detroit
- OSTI ID:
- 6438151
- Journal Information:
- Cancer Res.; (United States), Vol. 44:10
- Country of Publication:
- United States
- Language:
- English
Similar Records
Detection of ductal dysplasia in mammary outgrowths derived from carcinogen-treated virgin female BALB/c mice
Morphological and histological characteristics of mammary dysplasias occurring in cell dissociation-derived murine mammary outgrowths
Related Subjects
BENZANTHRACENE
TOXICITY
DIMETHYLBENZANTHRACENE
SOMATIC CELLS
BIOLOGICAL RADIATION EFFECTS
CELL PROLIFERATION
CARCINOGENESIS
CARCINOMAS
GAMMA RADIATION
MAMMARY GLANDS
MICE
ONCOGENIC TRANSFORMATIONS
ANIMAL CELLS
ANIMALS
AROMATICS
BIOLOGICAL EFFECTS
BODY
CONDENSED AROMATICS
DISEASES
ELECTROMAGNETIC RADIATION
GLANDS
HYDROCARBONS
IONIZING RADIATIONS
MAMMALS
NEOPLASMS
ORGANIC COMPOUNDS
ORGANS
PATHOGENESIS
RADIATION EFFECTS
RADIATIONS
RODENTS
VERTEBRATES
560305* - Chemicals Metabolism & Toxicology- Vertebrates- (-1987)