Anti-tumor Mechanisms Of Four Monomer Compounds On Prostate And Breast Cancer Cell Lines

Cancer is a refractory disease that impairs public health,its halmfulness only ranks behind cardiovascular disease,making it the second leading cause of death in China.Due to the ocurrence of tumor multi-drug resistance,finding new anticancer drugs with new structure and anticancer mechanism seems to be particularly important.In this paper,we took natural products Capilliposide B,Capilliposide C,and Chalocomoracin,and laboratory synthesis EM340 as subjects to study their anti-tumor mechanism.The first part is about the antiprostate cancer mechanism of monomeric compounds CPS-B and CPS-C,which are novel oleanane triterpenoid saponins derived from L.capillipes.Early study has shown the anti-tumor effect of LC in vivo.But still,we do not know the exact anti-tumor mechanism of CPS-B and CPS-C.This thesis first applied cell viability assay to test the anti-proliferation ability of CPS-B,CPS-C on prostate cancer cell lines PC-3 and DU145.After 48 hours treatment,the IC50 of CPS-B on PC3 and DU145 was 3.75?M and 4.0?M,IC50 of CPS-C on PC-3 and DU145 was 5.53?M and 9.99?M,respectively.Then we took PC-3 cell line to study the anti-tumor mechanism of CPS-B and CPS-C.Results showed that CPS-B induced DNA damage and apoptosis,followed by increase of ROS,activation of AMPK-mTOR pathway,leading to autophagy and cell adhesion and migration inhibition.And CPS-C-mediated cell apoptosis via regulation of mitochondria function and MAPK,Caspase and Bcl-2 family protein expression.The second part is about the anti-tumor mechanism of compound EM340 on breast cancer cells.First,we took YAP as target and applied YAP reporter assay to screen the positive anti-YAP expression compound and achieved the compound EM340.Further study revealed that EM340-mediated breast cancer cell death via activation of Hippo pathway and downregulation of YAP.On the other hand,blocking E3 ubiquitin ligase ?-TRCP with non-functional E3 ubiqutin ligase ?F-?-TRCP maintained YAP expression,suggesting EM340-induced YAP degradation via ?-TRCP.The RT-PCR and qPCR data revealed that EM340 downregulated the expression of YAP downsteam target transcriptianl factors CTGF,Cyr61 and stemness factors Oct3/4,Sox2,Nanog.In conclusion,EM340-mediated cell death via targeting LATS1 kinase of Hippo pathway,and downregulation of YAP and its downstream transcriptional signals.The third part is about the anti prostate and breast cancer mechanism of Diels-Alder CMR.Results showed that CMR caused cytoplasmic vacuolation in PC-3 and MDA-MB-231 cells,leading to cell death(LNCaP cells did not show this phenomenon).Further study revealed that CMR induced ROS,mitochondria membrane potential loss and damaged the balance of cytoplasmic calcium ion,along with the activation of LC3-?,Ubiquitin related protein and PINK1,leading to cell mitophagy.On the other hand,CMR caused downregulation of paraptosis inhibitor Alix,suggesting occurrence of paraptosis.Further study of the phenotype of LNCaP after treating with CMR illustrated that PINK1 played an important role between CMR-mediated mitophagy and paraptosis.Main innovative works of this thesis are as follows:(1)First conducted an in-depth research on the anti-tumor mechanism of CPS-B and CPS-C.(2)YAP reporter assay based screening.And the results showed that EM340 is the activator of LATS1 kinase for the first time.(3)CMR-mediated PC-3 and MDA-MB-231 cell death via a novel pathway-paraptosis.