Is there an accumulation of cells during G2 in some acute lymphoblastic leukaemias?
In some cases of acute lymphoblastic leukaemia (ALL) the percentage of cells in G2 + M is higher than anticipated when compared with the percentage in S phase. This increase in G2 + M, as detected by flow cytometry measurement of DNA content, may be due to an accumulation of cells, either in G2 or during the end of S phase; it may also be related to the existence of small tetraploid clones generally ignored by cytogeneticists. In order to identify possible subpopulations of cells with a DNA index greater than or equal to 2.0, we have compared the results of a cytogenetic analysis to the G2 + M values. We have also studied the distribution of S phase cells in 24 cases of ALL by incorporating 5-bromodeoxyuridine, labelling the cells by indirect immunofluorescence, and analysing them by flow cytometry after propidium iodide staining. The distribution of cells during S phase was quantified: no accumulation of cells was ever observed at the end of S phase. The question of the existence of small tetraploid clones, G2 arrested cells or cells with a G2 elongation remains open. However, we feel that it is more probable that, in this pathology, an elongation of the duration of G2 occurs.
Laboratory of Analytic Cytology, Faculty of Medicine, Lyon, France.
M
M
Ffrench
J P
JP
Magaud
M
M
Arzounian
C
C
Souchier
C
C
Charrin
P A
PA
Bryon
D000293:Adolescent; D000328:Adult; D000368:Aged; D001853:Bone Marrow / Q000473:pathology* / Q000648:ultrastructure; D001973:Bromodeoxyuridine; D002452:Cell Count; D002648:Child; D002675:Child, Preschool; D004273:DNA, Neoplasm / Q000032:analysis*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007223:Infant; D007399:Interphase; D007621:Karyotyping; D008214:Lymphocytes / Q000473:pathology; D008297:Male; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000473:pathology*; D011419:Propidium; D013194:Staining and Labeling
D004273:DNA, Neoplasm; D011419:Propidium; D001973:Bromodeoxyuridine