Study Of GGTI-2133on Proliferation, Migration, Apoptosis, Chemotherapy Sensitivity In Prostate Cancer Cell And It’s Mechanisms

Objective：To investigate the effect of GGTI-2133(GGTaseI inhibitor) on cultured prostatecancer cell proliferation, apoptosis, migration in the experiment, and detect itsinfluence in the tumor cells to the chemotherapeutic drug sensitivity.Otherwise,wewill discuss the possible mechanisms of GGTI-2133on human prostate cancerproliferation, apoptosis, migration and chemo-sensitivity impact.Methods:The first part:(1)cultured human prostate cancer DU145cells and established cellexperimental model in vitro.(2) DU145cells were treated with different doses ofGGTI-2133in the same time or the same dose in the different times.Used the Invertedoptical microscope to observe and MTT assay to detect the effect of GGTI-2133onDU145cell proliferation.Used the FACS assay to detect the cell cycle of DU145cellstreated with different doses of GGTI-2133after24h,and calculate the value of the cellproliferation index (PI).(3)Use the TUNEI assay to detect the apoptosis of DU145cells treated with different doses of GGTI-2133after24h.(4)Used the transwellchamber to observe the migration of DU145cells of control group and experimentalgroup.(5)Used the MTT assay to measure the IC50of adriamycin on DU145cellswhen adriamycin was used alone or in combination with GGTI-2133（5μmol/L).The second part:Used western blot to detect the expression of RALA-GTP,RALB-GTP,RALBP1,REPS2/POB1,TBK1and NF-κB protein,and RT-PCR to detect theexpression of Bcl-2and Bax gene in DU145cells which were treated with differentdoses of GGTI-2133after24h.Results:The first part:(1)The proliferation of DU145cells was inhibited.Used the Inverted optical microscope and MTT assay,we could find that the cell proliferation rate wasdown-regulated as the treatment concentration increased or the culture timeextended.GGTI-2133could induce DU145cell cycle arrest at G0/G1,and the PI ofexperimental group was reduced compared with control group(P<0.05).(2)GGTI-2133could promote DU145cells apoptosis,and the apoptosis rate of experimental groupwas increased compared with control group(P<0.05).The expression of Bcl-2genewas down-regulated and Bax was up-regulated.(3) the migration of experimentalgroup was inhibited,and the number of experimental group cells(37±16.29) whichmigrated to the under surface of transwell plate was lower than control group(327±22.13)(P<0.01).(4) The IC50of the groups which were treated with adriamycin alonewas10.1190±0.1220,and the groups treated with adriamycin in combination withGGTI-2133（5μmol/L) was5.7600±0.0580.There were significant differencesbetween them(P<0.05).The second part:(1)Along with the concentration of GGTI-2133(5～20μmol/L) incr-ease,the expression of RALA-GTP,RALB-GTP,RALBP1,TBK1and NF-κB proteinwas down-regulated,but the expression of REPS2/POB1protein was up-regulated.There were significant differences between them and the control group(P<0.05).(2)GGTI-2133could down-regulated Bcl-2gene and up-regulated Bax gene expressionin a dose-dependent manner.Conclusions:1.In a certain range of concentration and time,GGTI-2133could inhibit the prolifer-ation and migration, promote apoptosis and improve Adriamycin chemo-sensitivityof human prostate cancer cells in vitro.2.The possible mechanisms of GGTI-2133on human prostate cancer proliferation,apoptosis, migration and chemosensitivity impact is that:GGTI-2133could block theactivation of the RalGEF-Ral signal pathway,and it mainly inhibits Ral-GDPconverted to Ral-GTP. And then affect the downstream-related protein (RALBP1,REPS2/POB1,TBK1,NF-κB, et al) expression and the downstream signal pathways(NF-κB signal pathway,et al) activation.Otherwise,at the apoptosis of prostate cancercells,GGTI-2133could also promote cells apoptosis by the way of decreasing Bcl-2 gene expression and increasing Bax gene expression.