Murine L1210 and P388 Leukemias

L1210 and P388 leukemia models have been extensively used over the last 50 years. The models are rapid, reproducible, and relatively inexpensive (in comparison to human tumor xenograft and transgenic models). However, as with any experimental animal tumor model, there are limitations. Neither leukemia is a satisfactory model for either human cancer in general or human leukemia in particular. Despite the limitations of murine leukemia models, these models have been useful in making progress in anticancer drug development, in the development of a number of therapeutic principles, and in understanding the biologic behavior of tumor and host. These models are still useful today in conducting detailed evaluations of new candidate anticancer drugs (e.g., schedule dependency, route of administration dependency, formulation comparison, analog comparison, and combination chemotherapy). The greatest utility of murine leukemias today is derived from evaluations of drug-resistant sublines for crossresistance and collateral sensitivity. Crossresistance data, coupled with knowledge of resistance mechanisms operative in drug-resistant leukemias, may yield insights into mechanisms of action of agents. Similarly, crossresistance data, coupled with mechanisms of action of various agents, may yield insights into resistance mechanisms operative in drug-resistant leukemias. Furthermore, crossresistance data may identify potentially useful guides for patient selection for clinical trials of new antitumor drugs.