Biology of the human myeloma cell population. II. Cytokinetic characteristics.
A kinetic study of five human myeloma cell populations before and after chemotherapy using cytochemical and autoradiographical techniques showed: 1. a large number of cells, with a DNA content intermediate between 2c and 4c, that did not incorporate thymidine ('U' cells) and were indicative of ineffective myelomapoiesis; 2. non cell cycle-specific (cyclophosphamide) followed by cell cycle-specific (vincristine) treatment led to an increase in the 3H-thymidine labelling index (LI) and activation of macromolecular synthesis (increased uridine and leucine uptake and actinomycin binding capacity) pointing to early cell recruitment. A high percentage of 'U' cells can be found even after therapy. The LI variations make it clear that recruitment after therapy is overestimated by at least 40% due to ineffective myelomapoiesis. In the light of this and previous personal studies, we propose a kinetic pattern: the myeloma population may be seen as a highly differentiating population whose non-proliferating cells cannot re-enter the cycle. By contrast, the acute leukemia populations are unable to differentiate, and the non-proliferating cells (G0) can be recalled into the cell cycle.
D002453:Cell Cycle; D003520:Cyclophosphamide / Q000627:therapeutic use; D004273:DNA, Neoplasm / Q000378:metabolism*; D003609:Dactinomycin / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D007930:Leucine / Q000378:metabolism; D009101:Multiple Myeloma / Q000188:drug therapy / Q000378:metabolism*; D013936:Thymidine / Q000378:metabolism; D014529:Uridine / Q000378:metabolism; D014750:Vincristine / Q000627:therapeutic use
D004273:DNA, Neoplasm; D003609:Dactinomycin; D014750:Vincristine; D003520:Cyclophosphamide; D007930:Leucine; D013936:Thymidine; D014529:Uridine