AN IN VIVO DOUBLE LABELLING STUDY OF THE SUBSEQUENT FATE OF CELLS ARRESTED IN METAPHASE BY VINCRISTINE IN THE JB-1 MOUSE ASCITES TUMOUR

Abstract

The fate of cells arrested by vincristine (VCR) in metaphase is of interest because of the wide use of this substance in cancer chemotherapy and in relation to its use in synchronization therapy. The present study was designed to answer the question of whether cells blocked in metaphase by VCR subsequently proliferate further or whether they become infertile and die. By means of a double labeling technique with [3H]- and [14C]-thymidine (TdR), it was shown that all VCR-arrested metaphases in [mouse] JB-1 ascites tumor cells subsequently became necrotic. These cells did not re-enter a viable G2 phase following arrest and could not take part in a wave of synchronous proliferation. In agreement with earlier studies, VCR led to arrest in metaphase, not only of cells in or shortly prior to mitosis at the time of VCR administration, but also of the majority of cells which had at this time been in the S and G2 phase.