SEPARATION AND CHARACTERIZATION OF THE NEOPLASTIC AND STROMAL ELEMENTS OF THE R3230AC MAMMARY ADENOCARCINOMA

  • 1 January 1981
    • journal article
    • research article
    • Vol. 41  (12) , 5064-5069
Abstract
The purification of the various types of cells in solid tumors is necessary for study of their biochemical and immunological functions. The [rat] R3230AC [mammary] adenocarcinoma contains a variety of stromal cells and well-differentiated neoplastic cells that possess many of the biosynthetic capabilities of normal rat mammary cells. Suspensions of cells from tumors weighing < 1.2 g consisted of 70.4 .+-. 7.2% (SD) malignant cells by morphology, 6.8 .+-. 3.0% lymphocytes, 6.3 .+-. 3.2% macrophages, 15.2 .+-. 5.2% red blood cells, 0.8 .+-. 0.5% granulocytes and 0.5 .+-. 0.6% unidentified cells. Sedimentation of the cells from the R3230AC tumor in a previously described isokinetic gradient resulted in a 5- to 6-fold purification of lymphocytes and macrophages. The modal fraction of malignant cells contained 95.3 .+-. 2.9% malignant cells. Detection of .alpha.-lactalbumin by the direct peroxidase conjugate technique gave vacuolar staining of malignant cells, in contrast to the indirect and peroxidase-antiperoxidase techniques which stained ducts from normal lactating mammary gland and a wide variety of cells without vacuoles in the tumor. The best fixative for frozen sections, paraffin-embedded tissue and cell suspensions was 50% ethanol-50% acetone. The suspensions of tumor cells contained 14.4 .+-. 9.4% cells with histochemically demonstrable .alpha.-lactalbumin. Squamous metaplasia was commonly observed in tumors from lactating rats.