Neoplastic Cell Clone Research Articles

Induction of yolk-sac tumors in the pregnant rat

Since the fetus is an allogeneic graft in the uterus of the mother, at least in all pregnancies resulting from heterospecific matings, nature must have provided some particular protective mechanism to prevent its rejection. To explain the peculiar immunological fetal-maternal relationship, different theories have been proposed, none of which is entirely supported by the experimental data (Beer and Billingham, 1971). Whatever the protective mechanisminvolved, we thought it worthwhile to explore the possibility that this special immunological relationship between fetus and mother may be used in experimental oncology. It is a well established finding that many oncogenie viruses only give rise to tumors when injected in immunologically poorly competent animals, e.g. newborns or immunosuppressed rodents. The resistance of adult competent animals to the oncogenie activity of viruses is based upon the development in these animals of an efficient cellular immunity directed against the tumor-associated transplantation antigens (TATA). This cellular immunity leads then to the rejection of the neoplastic cell clones. Since during pregnancy the fetal environment is protected against immune aggression of maternal sensitized lymphocytes, the pregnant uterus may be a privileged site for the induction of tumors of viral origin and displaying strong TATA.

Uptake and metabolism of histamine by neoplastic mast cells

Furth mast cells grown in mice as an ascitic tumour and incubated in vitro took up histamine from the medium. The curve obtained by plotting the net uptake against concentrations in the medium suggests that the uptake of histamine occurred through an active process. Histamine uptake was inhibited both by lowering the temperature and by adding iodoacetic acid. This cell line did not metabolize histamine to any significant extent. The biological characteristics of different mast cell clones are discussed, in view of using this system for studying drug actions on mast cell histamine. Clones of neoplastic mast cells have provided a reliable model for studies of the uptake of histamine ( Day and Green 1962, Day and Stockbridge 1964, Furano and Green 1964, Green 1966, Mannaioni et al. 1968, Green 1968). However, the nature of the uptake process and the ability of neoplastic mast cells to metabolize histamine are still at issue.

Immunoglobulin synthesis and secretion. VI. Synthesis and intracellular transport of immunoglobulin in nonsecretory lymphoma cells.

Cells from an established line of Burkitt's lymphoma (Daudi) and a mouse myeloma (P(3)K) were pulse-labeled in vitro with (3)H-leucine, and immunoglobulin was immunologically precipitated from cell lysates and secretions. In contrast to P(3)K cells, Daudi cells synthesize a small amount of Ig which is not secreted. Subcellular fractionation experiments indicated that Ig of Daudi cells is synthesized on membrane-bound polyribosomes and enters the cisternae of the microsomes. Ig in the microsomes could be labeled with either (3)H-galactose or (3)H-fucose suggesting that transport proceeds to the Golgi complex. Additional evidence indicates that Ig molecules are transported to the plasma membrane but are not cleaved from the cell surface. These results together with other studies of Burkitt lymphoma cells suggest that the Daudi line may represent a clone of neoplastic cells derived from normal lymphocytes which synthesize but do not secrete Ig. Similarities between lymphoma cells and antigen-binding cells are discussed.