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.
Ffrench
M
M
Laboratory of Analytic Cytology, Faculty of Medicine, Lyon, France.
Magaud
J P
JP
Arzounian
M
M
Souchier
C
C
Charrin
C
C
Bryon
P A
PA
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