Comparison of S-phase fractions measured by flow cytometry and autoradiography in human transplant tumors

✍ Scribed by Dr. G. Feichter; W. Czech; D. Haag; K. Goerttler; G. Futterman; H. Loehrke; U. Abel

• Publisher: John Wiley and Sons
• Year: 1988
• Tongue: English
• Weight: 667 KB
• Volume: 9
• Category: Article
• ISSN: 0196-4763
• DOI: 10.1002/cyto.990090615

✦ Synopsis

The "H-thymidine labeling index (TLI) and the percentage of cells in the S-phase have been determined by autoradiography and by flow cytometry, (FCM), respectively, in six malignant tumors of human origin transplanted on athymic nude mice. The Dean and Jett model and the graphical model were used to determine the percent of S-phase cells by FCM. Cell cycle analysis was performed using 1) no correction for background; 2) an algebraic function for background correction; and 3) an exponential function for background subtraction. Each of these three data sets was evaluated using both the Dean and Jett model and a graphical model for the evaluation of DNA histograms. The S-phase fractions (SPF) were compared to the corresponding labeling index results.

SPF without background correction were 1.54 times higher than the TLI. SPF, after correction using the algebraic model, were 1.29-fold higher than the TLI, whereas SPF obtained after background subtraction ac-cording to the exponential model were only 1.05-fold higher than the TLI. Student's t-test revealed significant differences between the mean TLI values (16.25 9.06) and the mean SPF obtained by FCM without background correction (mean 25.0 f 9.36, P < O M ) , but not between the mean TLI values and the mean SPF percentages after algebraic (mean 21.0 10.29) and exponential background correction (mean 17.11 +_ 11.591, P > 0.05 each.

There was no difference between the results obtained using the Dean and Jett model and those obtained usinff the graphic evaluation.

The SPF obtained by FCM are similar to the "-thymidine labeling indices of the same sample of a solid tumor if the histograms first are cleaned from nonspecific background pulses.