Characterization of cell cycle and biological parameters of transplantable glioma cell lines and clones

Summary Aberrant biological characteristics of established cell lines and clones, derived from nitrosourea-induced gliomas in CDF rats were compared with normal rat glial cells. Despite their tumorigenicity and unrestrained proliferation due to inherent cytogenetic anomalies, these neoplastic cells retained certain normal glial attributes to a variable degree. Differentiated glioma cells resembled normal glial cells to a greater extent than they resembled anaplastic glioma cells. They were also less malignant upon implantation. Cell cycle analyses revealed that considerable variations not only for the G1 phase but also for the S period were demonstrated among different tumor cell types. Shortening of the G1 phase may dictate a shorter generation time (shorter doubling time) since a larger potential proliferative pool may overcome the effect of a prolonged generation period and may constitute a faster proliferation rate. Although the cell generation period of neoplastic cells is not necessarily shorter than that of normal glial cells, the lower proportion of non-proliferative cells results in a much faster growth rate when compared to non-neoplastic glial cells in culture.This investigation was supported in part by grants CA-11224 and CA-20348 from the National Cancer InstituteRecipient of the Government Scholarship awarded by the Ministry of Education, The Republic of China (Taiwan)