ABSTRACT
Aim To explore the role of progesterone re-ceptor B ( PRB ) in regulation of medroxyprogesterone acetate ( MPA) sensitivity in endometrial cancer cells, and to investigate the effect of MPA on the biological character in Ishikawa cells infected with shRNA targe-ting PRB gene. Methods Ishikawa cells were stably transfected with PRB shRNA using lentivirus to knock-down endogenous PRB expression. Real-time fluores-cent quantitative PCR was applied to confirm the knockdown effect. MTT assay, flow cytometry and cell invasion assay were applied to detect the influence of MPA on endometrial cancer cell proliferation, apopto-sis and invasion. We also used Western blot assay to detect the effect of MPA induced the activation of ERK/MAPK signal pathway. Results Recombinant lentiviral vector expressing shRNA targeting PRB gene was successfully established, results of real-time PCR and Western blot showed that compared with control group, PRB expression in Ishikawa cells infected with shRNA decreased obviously ( P <0.01 ); MPA could repress endometrial cancer cells proliferation and inva-sion, meanwhile promoted its apoptosis ( P <0.01 ) . However, the effect was almost reverse in Ishikawa cells infected with shRNA. Furthermore, MPA induced ERK/MAPK activation in Ishikawa cells infected with shRNA. Conclusions PRB plays a role in regulating therapeutic sensitivity of MPA in endometrial cancer cells;and for Ishikawa cells infected with shRNA tar-geting PRB gene, MPA has effects on the biological character via pERK1/2-MAPK signal pathway.