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E2F1 regulates an apoptotic response to AKT inhibition in prostate cancer
전립선암에서 AKT 저해에 의한 세포자멸 반응을 조절하는 E2F1의 작용

DC Field Value Language
dc.contributor.advisor전주홍-
dc.contributor.author김수화-
dc.date.accessioned2017-07-14T01:21:00Z-
dc.date.available2017-07-14T01:21:00Z-
dc.date.issued2012-08-
dc.identifier.other000000005019-
dc.identifier.urihttp://hdl.handle.net/10371/121860-
dc.description학위논문 (박사)-- 서울대학교 대학원 : 의학과 생리학 전공, 2012. 8. 전주홍.-
dc.description.abstractThe progression of prostate cancer is associated with a selective growth advantage under androgen-depleted conditions, which is accompanied by notorious resistance to most available therapies. Recently geraniol, a naturally occurring monoterpene, has been reported to possess chemotherapeutic potentials against colon and pancreatic cancers. However, the mechanisms of the geraniol action against prostate cancer are poorly understood. In this study, I investigated the anticancer activity of geraniol against prostate cancer.
First, in part Ⅰ, I found that geraniol induces G1 arrest and apoptosis in PC-3 androgen-independent prostate cancer cells. Xenograft model experiments demonstrate that geraniol reduces tumor volumes and weights. In addition, I showed that geraniol increases the sensitivity of prostate cancer to various chemotherapeutic agents in cultured cells and then demonstrate that the combination of sub-optimal dose of geraniol and docetaxel noticeably suppresses prostate cancer growth in tumor xenograft mice. Next, I investigated the molecular mechanisms of geraniol-induced cell death in PC-3 prostate cancer cells. Among the examined structurally and functionally similar monoterpenes, geraniol specifically induced apoptosis and autophagy. Although independent processes, apoptosis and autophagy acted as cooperative partners to elicit geraniol-induced cell death in PC-3 cells. At a molecular level, geraniol inhibited AKT signaling and activated AMPK signaling, resulting in mTOR inhibition. Combined treatment of AKT inhibitor and AMPK activator markedly suppressed cell growth compared to either treatment alone. My findings provide insight into future investigations that are aimed at elucidating the role of apoptosis and autophagy in prostate cancer therapy and at developing the anticancer strategies deregulating AKT/mTOR pathway.
AKT/mTOR pathway has been reported to possess chemotherapeutic potentials in most of cancers, since PTEN loss and decreased expression of androgen receptor provide activated survival pathway, which confers growth advantages by achieving self-sufficiency in growth signals. However, AKT/mTOR pathway is associated with receptor tyrosine kinase family by negative feedback network. Recent several reports showed that inhibition of AKT/mTOR pathway relieves the negative feedback loop of receptor tyrosine kinase family. In addition, AKT knockdown did not induce apoptosis, thereby it did not promote profound cell death as a therapeutic approach. Therefore, in part Ⅱ, I used network analysis to assume molecule, which induces synthetic lethality with AKT. As a result of network modeling, I found that E2F1 as a critical hub is down-regulated by high dose of AKT inhibitors. This dose causes significant cell death. In addition I found that inhibition of E2F1 is associated with inhibition of receptor tyrosine kinase family expression and activity. Consequently, I suggest that, in CRPC cells in which achieve growth advantage through hyper-activated oncogenic pathway, combined inhibition of AKT and E2F1 is more effective than either alone.
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dc.description.tableofcontentsABSTRACT ------------------------------------------------------- i
CONTENTS ---------------------------------------------------- iV
LIST OF FIGURES ------------------------------------------- Vii
LIST OF TABLES ---------------------------------------------- X
LIST OF ABBREVIATIONS -------------------------------- Xi
I. INTRODUCTION -------------------------------------------- 1
II. AIMS OF THE STUDY ------------------------------------- 8
III. MATERIALS AND METHODS ------------------------- 9
1. Cell cultures and Reagents
2. MTT assay
3. Flow cytometry analysis
4. Caspase-3 activity assay
5. Assessment of mitochondrial membrane depolarization
6. Whole-Cell Patch Clamp Analysis
7. Ca2+ measurement
8. Quantitative analysis of GFP-LC3 dot
9. Xenograft experiment
10. RNA isolation and microarray experiments
11. Network analysis
12. Western blot analysis
13. siRNA transfection
14. Statistic analysis
IV. RESULTS --------------------------------------------------- 22
1. Part 1
1.1 Geraniol suppresses PC-3 cell growth in vitro
1.2 Geraniol induces cell cycle arrest and apoptosis in PC-3 cells
1.3 Geraniol inhibits PC-3 cell growth in a xenograft model
1.4 Geraniol inhibition of cell growth is independent of TRPM8 calcium channel
1.5 Geraniol increases the chemosensitivity of PC-3 cells in vitro
1.6 Geraniol increases the chemosensitivity of PC-3 cells in vivo
1.7 Geraniol induces apoptosis and autophagy in PC-3 cells
1.8 Geraniol-induced apoptosis and autophagy cooperate to elicit cell death in PC-3 cells
1.9 The effects of geraniol is unrelated to HMG-CoA reductase and TRPM8 pathways in PC-3 cells
1.10 Geraniol inhibits AKT-mTOR signaling in PC-3 cells
1.11 Geraniol activates AMPK signaling in PC-3 cells
2. Part 2
2.1 AKT inhibitors induce cell death
2.2 AKT knockdown does not induce apoptosis
2.3 E2F1 is a key hub that is closely located to AKT
2.4 AKT inhibitors down-regulate E2F1 expression
2.5 The sub-network between AKT1 and E2F1 consists of receptor tyrosine kinase related genes
2.6 Down-regulated E2F1 mediates decrease of RTK expression and activity
2.7 Combined suppression of AKT and E2F1 expression induces apoptosis
V. DISCUSSION ------------------------------------------------ 77
VI. REFERENCES -------------------------------------------- 85
VII. ABSTRACT (KOREAN) ------------------------------- 96
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dc.formatapplication/pdf-
dc.format.extent2724562 bytes-
dc.format.mediumapplication/pdf-
dc.language.isoen-
dc.publisher서울대학교 대학원-
dc.subjectGeraniol-
dc.subjectAKT-
dc.subjectE2F1-
dc.subjectCell death-
dc.subjectProstate cancer-
dc.titleE2F1 regulates an apoptotic response to AKT inhibition in prostate cancer-
dc.title.alternative전립선암에서 AKT 저해에 의한 세포자멸 반응을 조절하는 E2F1의 작용-
dc.typeThesis-
dc.contributor.AlternativeAuthorKim Su Hwa-
dc.description.degreeDoctor-
dc.citation.pagesiV,96-
dc.contributor.affiliation의과대학 의학과-
dc.date.awarded2012-08-
Appears in Collections:
College of Medicine/School of Medicine (의과대학/대학원)Dept. of Medicine (의학과)Theses (Ph.D. / Sc.D._의학과)
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