Profile of cell cycle in hematopoietic malignancy by DNA/RNA quantitation using 7AAD/PY.

We analyzed the surface phenotypes and cell cycle of twenty two hemopoietic cell lines using 7AAD/PY based on the cellular DNA/RNA content. Populations of G1a, G1b, S, and G2+M, DNA index (DI), and the RNA index of S phase (SRI) were calculated by means of DNA/RNA dot plots. Two new parameters were extracted from the cell cycle profiles, namely, the nucleic acid index of the S phase (NI) and the coefficient of variations in the RNA at S phase (SCV). DNA/RNA dot plots of cell lines revealed four characteristic profiles of the cell cycle defined with the calculated NI and SCV. These were Type 0 (small NI, large SCV), Type I (small NI, small SCV), Type II (large NI, small SCV) and Type III (large NI, large SCV). Type 0 included four stem cell lines: a t(1;19) leukemia, two Ph 1 positive ALL and a biphenotypic crisis of CGL. Type I included five ALL cell lines: three T-ALL and two common B-ALL. Type II contained ten myeloid cell lines: five AML and five myeloid crisis of CGL and Type III consisted of three relatively immature lymphoma cell lines: two Burkitt's lymphoma and a follicular center lymphoma cell line. Calculated (NI / SCV(%)) were as follows: Type 0 2.27+0.19 / 16.7+3.7; Type I 2.20+0.30 / 11.1+0.7; Type II 3.64+0.52 / 11.8+1.0 and Type III 3.60+0.53 / 17.5+1.9. Cell cycle analysis of blasts using 7AAD/PY combined with surface phenotyping may yield important and rapid information for the classification of hematopoietic malignancy within 2 hours of patient admission.