Continuous Cell Lines as an Experimental Model for Bladder Cancer Chemotherapy

Abstract

Numerous systems are used in experimental cancer chemotherapy, including induced and transplantable animal tumours, human tumour xenografts and a variety of tissue culture methods. Each of these models has limitations. Continuous cell lines are unique in providing a pure, reproducible and relatively homogeneous population of human tumours cells. Their in vitro drug sensitivities may be of particular relevance to intravesical chemotherapy, because in contrast to systemic administration the duration and drug concentration to which the tumour cells will be exposed are known. Therefore, the biological and growth characteristics of twelve continuous cell lines derived from transitional cell cancers of the human bladder were determined, including tumorigenicity in “nude” mice and isozyme patterns. Population doubling times ranged from 17–93hr and colony forming efficiency from 3–87%.In vitro sensitivities to adriamycin and methotrexate were determined using clonogenic assays. Profound differences in sensitivity were observed, the proportion of surviving clonogenic cells following exposure to 30ng/ml adriamycin ranging from 0.7–42.0% and to 100ng/ml methotrexate from 1.5–89.5%. It is concluded that this panel of cell lines shows a wide range of biological characteristics and drug sensitivities, perhaps comparable to those encountered clinically in this disease, and may provide a model system with which to conduct in vitro phase II trials.