Differences in cell kinetic changes among renal cancer cell lines treated with interferon-alpha

Background: Interferon (IFN)-alpha shows certain clinical effects on the tr eatment of renal cell carcinoma. The purpose of the present study was to in vestigate its direct effects and to compare the responses among different h uman renal cancer cell lines. Methods: Three cell lines, ACHN, RCC10RGB and OS-RC-2, were incubated with IFN-alpha and evaluated using MTT assay for cell proliferation and two-colo r flow cytometry for cell-cycle-specific cyclin expressions coupled with DN A ploidy analysis. Results: Interferon-alpha inhibited cell proliferation and caused cell accu mulation at S and G2/M phases. However, IFN-alpha induced no significant ch ange in cyclins D1, E, A or B1 expression. Interestingly, cell kinetic chan ges caused by IFN-alpha were different among cell lines. Cell proliferation was suppressed most in ACHN, then RCC10RGB and least in OS-RC-2. Comparing DNA histograms, ACHN showed distinct increase of G2/M cells associated wit h elevation of late S cells. RCC10RGB showed a predominant increase of whol e S cells accompanied with a slight increase of G2/M. OS-RC-2 showed a mode st increase of S cells with a little change of G2/M cells. Chronological ob servation revealed that S-phase increase and proliferative inhibition appea red on day 1 and day 3, respectively, in ACHN and RCC10RGB, and on day 5 in OS-RC-2. Conclusions: Interferon-a induced substantial cell kinetic interference dir ectly in the tested human renal carcinoma cell lines. The degree of change was different according to the nature of the cell line. It may partly indic ate the variety of the efficacy of IFN-alpha treatment against renal cancer s.