ABSTRACT
Cell culture and transplantation techniques both allow the investigator to separate humoral and cellular factors involved in biological processes. Tissue culture methods allow to a controlled environment and transplantation methods allow the analysis of the biological behavior of altered cells and also allows to study the effects of the host environment on cells of known biological activity. Thus, most tissue culture cells are similar in surface structure and mitochondrial pattern and show an increase in pinocytosis and phagocytosis and an alteration in the distribution of intracellular filaments associated with attachment and cell movement. The cells were not tested for tumor production by transplantation. The bladder cells, in contrast to the normal and the in vivo situation, continued to divide rapidly and exfoliate. Although the three tumors they used to initiate the cultures were induced by the same carcinogen and were similar in structure, the three cell lines derived from them differed greatly in morphology and behavior.
