Regulation of growth inhibition by transforming growth factor beta1 in rhabdomyosarcoma RD cell line

Abstract

To study the regulatory effect of TGF-beta1 on growth of rhabdomyosarcoma RD cell line. After various durations of TGF-beta1 treatment, the viability of RD cell line was examined by growth rate measurement, MTT assay and (3)H-thymidine incorporation. The cell cycle was analyzed by flow cytometry. Immunofluorescent staining was used to localize p15, p21 and p27 in RD cell line under laser scanning confocal microscope. The protein and mRNA of p15, p21 and p27 in RD cell line were detected by western blot and reverse transcriptase-polymerase chain reaction respectively. The viability of RD cell line treated with TGF-beta1 was obviously decreased. RD cell line was arrested in G(1) phase by TGF-beta1. There was increased expression of p21 and p27 in RD cell line with TGF-beta1 treatment at protein and mRNA levels. The expression of p21 in RD cell line was seen in both nucleus and cytoplasm after 24 hours of TGF-beta1 treatment. The expression of p15 showed no obvious changes upon TGF-beta1 treatment. TGF-beta1 inhibits growth of RD cell line and induces G(1)-arrest. It up-regulates protein and mRNA of p21 and p27 and shows no obvious influence on p15 expression. The growth arrest of RD cell line may result from the up-regulation of p21 and p27 by TGF-beta1.