Lymphoid Cell Lines: In Vitro Cell Markers in Correlation to Tumorigenicity in Nude Mice

Abstract

The lack of satisfactory modes of separating in vivo tumor cells from reactive host tissues necessitates the search for in vitro tumor cell models as exact counterparts of the neoplastic tissue in vivo. These in vitro cells should exhibit the same morphological or functional markers, specifying their in vivo parent cells as neoplastic. From all human tissues lymphoid cells can be transferred to immortalized longterm cultures in vitro with the greatest ease. This fact in the past caused not only a magnitude of established lymphoid cell lines derived from neoplastic or non neoplastic origin, but also a great body of confusion concerning the question, whether these cells could be considered as truly neoplastic cells or not. Two recent investigations (3, 16) have successfully applied some cellular markers for the differentiation between the large number of lymphoblastoid cell lines (LCL), characterized as non-neoplastic cells, derived from malignant or nonmalignant tissue and the few lymphoma and myeloma lines, defined as neoplastic cells, exclusively originating from neoplastic tissue in vivo. The distinction was based mainly on parameters as karyotype, microscopic and ultrastructural morphology, immunological markers and the capacity of in vitro lines to grow in agar or form tumors following xenotransplantation in immunosuppressed animals.