BACKGROUNDRosiglitazone is known as the most potent and specific peroxisome proliferators-activated receptor gamma (PPAR-gamma) ligand. It has potentially far-reaching effects on pathophysiological processes, from cancer to atherosclerosis and diabetes. However, it is not clear whether rosiglitazone affects the protein expression of transforming growth factor beta3 (TGF-beta3) and the cell proliferation in human uterine leiomyoma cells in vitro.

METHODSHuman uterine leiomyoma tissues were dissected and cultured. Cells were divided into 5 groups: one control group and other four groups with different concentrations of rosiglitazone (10(-7), 10(-8), 10(-9) and 10(-10) mol/L). Cells were cultured for 72 hours in serum-free Dulbecco's modified Eagle's medium. MTT reduction assay was used to detect the cell proliferation. Reverse transcription polymerase chain reaction (RT-PCR) was used to detect the mRNA expression of PPAR-gamma and TGF-beta3. Immunofluorescence staining was used to detect the expressions of PPAR-gamma and TGF-beta3 proteins.

RESULTSMTT reduction assay indicated that the treatment with rosiglitazone (from 10(-7) to 10(-9) mol/L) resulted in an inhibition of the cell growths after 72 hours (P < 0.01). RT-PCR analysis revealed that 10(-7) mol/L rosiglitazone significantly affected the gene expression at 72-hour: PPAR-gamma mRNA expression was up-regulated and TGF-beta3 mRNA was down-regulated and rosiglitazone at the concentration of 10(-7) mol/L affected these most effectively (P < 0.01). Immunofluorescence staining demonstrated that treatment with 10(-7) mol/L rosiglitazone resulted in the significant changes of PPAR-gamma and TGF-beta3 protein expressions compared with the other treatment groups and the control group at 72-hour (P < 0.01). All the effects of rosiglitazone on uterine leiomyoma cells were dose- and time-dependent in vitro.

CONCLUSIONSThe present study demonstrates that the PPAR-gamma activator, rosiglitazone, inhibits the cell proliferation partly through the regulations of PPAR-gamma and TGF-beta3 expressions. The cross-talk between the signal pathways of PPAR-gamma and TGF-beta3 may be involved in the process.