The Primary Study Of The Effect Of Down-regulated PTTG1 Expression On Human Prostate Cancer LNCaP-AI Cell Proliferation And Senscence

Objective To investigate the effect of down-regulated PTTG1 expression by siRNA on human prostate cancer LNCaP-AI cell proliferation and senescence.Methods Human castration resistant prostate cancer LNCaP-AI cells were transfected by the specific interfering plasmids(siRNAs for PTTG1);The cell counting and the status of cell were performed with a hematocytometer and optical microscopy;Phenotypic characteristics of senescence of transfected human prostate cancer LNCaP-AI cells were examined by senescence-associated β-galactosidase(SA-β-gal)staining;Molecular characteristics of senescence of transfected human prostate cancer LNCaP-AI cells such as the senescence-related proteins Glb1,the cyclin-dependent kinase inhibitor p27Kip1,chromatin-regulating heterochromatin protein 1γ(HP1γ),the androgen recepter protein AR and so on were detected by Western blot.Results(1)In the process of transfection,transfection group cell growth curve appeared a downward trend than control group and negative control group(P<0.05);(2)The PTTG1 protein expression of transfected human prostate cancer LNCaP-AI cells were reduced than control group and negative control group(P<0.05);(3)Reducing the expression of PTTG1 induced elevated senescence-associated β-galactosidase(SA-β-gal)staining(P<0.05);(4)The expression of senescence-related proteins Glb1,the cyclin-dependent kinase inhibitor p27Kip1,p21,chromatin-regulating heterochromatin protein 1γ(HP1γ)were increased in human prostate cancer LNCaP-AI cells after transfection.The expression of the MAPK signaling pathway protein p-ERK,the PI3 K signaling pathway protein p-Ark,the androgen recepter protein AR were decreased in human prostate cancer LNCaP-AI cells after transfection(P<0.05);(5)LNCaP-AI cells with down-regulated PTTG1 expression showed moderately slower proliferation than control group and negative control group;However,while LNCa P-AI cells were still able to proliferate(albeit at a lower rate)in the androgen deprivation conditions(in CSS medium),cells with down-regulated PTTG1 expression failed to divide under androgen deprivation conditions(P<0.05).Conclusion(1)Reducing the expression of PTTG1 induces senescence of human prostate cancer LNCaP-AI;(2)PTTG1 gene may regulates development and advance of prostate cancer by cell senescence and AR signaling pathways.