Inhibition of Cell Division Cycle by Overexpression of TIS21/BTG2/PC3

DC Field Value Language
dc.contributor.advisor문은표, 임인경-
dc.contributor.author류민숙-
dc.date.accessioned2019-10-21T06:45:23Z-
dc.date.available2019-10-21T06:45:23Z-
dc.date.issued2005-
dc.identifier.other187-
dc.identifier.urihttps://dspace.ajou.ac.kr/handle/2018.oak/16244-
dc.description학위논문(박사)--아주대학교 대학원 :생명과학과,2005-
dc.description.abstract세포생장억제유전자인 TIS21 (TPA inducible sequences 21)은 early growth response genes의 한 종류이며 TPA을 처리한 SW3T3 세포에서 동정되었다. TPA에 의해 유도된 TIS21 mRNA의 발현은 즉각적이며 일시적이다. TIS21의 동종유전자에는 rat PC12 세포에서의 PC3 유전자와 인간에서의 BTG2 (B-cell translocation gene 2) 유전자가 존재한다. TIS21의 세포 생장 억제 기전을 연구하기 위해 우선 TIS21 유전자를 293 세포(p53와 Rb 단백질 기능이 불활성화된 세포)에 과발현시켰다. TIS21이 과발현되는 클론인 C9과 C11은 벡터가 도입된 V7과 V10 그리고 antisense가 도입된 AS1과 AS4보다 낮은 포화밀도를 보였으며 세포의 크기가 주요하게 커졌다. 혈청으로 유도시킨 세포주기를 관찰하기 위해 double thymidine 처리방법을 이용하여 FACS 분석을 실행하였다. V10은 정상적인 세포분열주기를 보이는 반면에 C9과 C11은 36시간까지 G1 주기에 세포가 머물려 있었다. 그러나 C9과 C11은 S 주기나 G2/M 주기로의 도입에는 영향이 없었다. 세포주기 조절 단백질들을 조사해 보았을 때, C9과 C11 세포는 Cyclin E 와 Cdk4 단백질의 합성이 현저히 억제되었으며 또한 Cyclin E-associated Cdk 활성도 억제되어 있었다. 이러한 실험결과로 293 세포(pRb와 p53이 불활성된 세포)에서 TIS21의 과발현은 Cyclin E와 Cdk4의 양적 감소로 G1-S 전이에 관련된 Cdk들의 활성이 감소된다는 결론을 내렸다. 그리고 한편 p53 기능이 결여된 U937 세포에서 TIS21을 과발현시켰을 때 다른 생장억제기전을 알게 되었다. TPA에 의해 유도된 TIS21의 발현은 PKC-δ 의 활성에 의하면 이는 cPKC isozymes에 의해 강하게 억제된다. U937 세포에 TPA와 Go6976가 처리되었을 때 TIS21 mRNA의 발현이 TPA 단독처리보다 오래 유지되었다. 이 현상은 TPA와 Go6850가 처리되었을 때는 보이지 않았다. FACS로 분석하였을 때, TPA에 의해 유도된 G2/M arrest는 Go6850에 의해 현저하게 억제되는데 이는 TIS21와 nPKC isozymes과의 관련성을 보여준다. 더불어 PKC-δ은 G2/M arrest와 TIS21 발현의 조절자로 알아냈으며, 그 TIS21 발현의 조절은 rottlerin과 dominant negative PKC-δ 실험으로 확인하였다. In vivo에서 TIS21 단백질의 축적은 caspase 3에 의한 세포 죽음을 유도하였으며, 이는 TIS21ΔC 발현세포에서 procaspase 3, full length PKC-δ, pRb 그리고 p21Waf1 분해로 확인되었다. 그리고 세포에 nocodazole를 처리 후 해제시켰을 때, 벡터 발현세포에서는 해제 3시간 후에 Cyclin A와 Cyclin B1의 분해가 급격하게 일어난 반면에 TIS21 과발현세포는 해제 3시간 후에도 Cyclin A와 Cyclin B1의 분해가 억제되었다. 더욱이 TIS21는 Cyclin B1-Cdc2 결합과 인산화효소 활성을 in vivo에서 억제시킨다는 결과를 얻게 되었다. 이 p53 기능이 결여된 U937 세포에서의 실험결과는 TPA에 의한 TIS21 mRNA 발현은 PKC-δ을 통해 유도되고, TIS21 단백질은 Cdc2와의 결합을 통해 Cyclin B1-Cdc2 결합과 그 인산화효소 활성을 억제함으로서 G2/M arrest 와 세포 죽음을 유도한다는 것을 말한다. 즉 결론은 TIS21의 발현은 p53과 pRb의 기능이 결여된 상태에서는 pRb independent pathway을 통해 Cyclin E와 Cdk4을 불활성 시켜 G1-S arrest을 유도하며, p53만 기능이 결여되고 pRb은 정상적인 경우에는 G1-S arrest가 아니라 Cyclin B1-Cdc2 기능을 억제하여 G2-M arrest을 유도하여 세포들의 생장을 억제한다는 것이다. 이는 p53 또는 pRb 기능이 결여된 많은 암세포에서 생장을 억제할 수 있는 기작으로 TIS21이 주요한 위치를 차지한다는 것을 암시한다.-
dc.description.tableofcontentsTables of Contents Abstract = ⅰ Tables of Contents = ⅲ List of Figures = ⅴ Chapter Ⅰ. Background and Literature Review = 1 1. 1. Introduction = 2 1. 2. Bibliographies = 16 Chapter Ⅱ. Induction of Growth Inhibition of 293 Cells by Downregulation of the Cyclin E and Cyclin-Dependent Kinase 4 Proteins Due to Overexpression of TIS21 = 23 2. 1. Introduction = 24 2. 2. Materials and methods = 26 2. 2. 1. Subcloning of TIS21 cDNA = 26 2. 2. 2. Transfection with TIS21 cDNA in pcDNA3 = 26 2. 2. 3. Cell Culture and Measurement of Cell Size = 27 2. 2. 4. Northern Blot Analysis = 28 2. 2. 5. Preparation of Recombinant TIS21 Protein and Antibody = 28 2. 2. 6. Visualization of TIS21 Protein = 29 2. 2. 7. Thymidine Double-Blocking and Measurement of Cell Cycles = 30 2. 2. 8. Detection of Cell-Cycle Regulators = 30 2. 2. 9. Histone H1 Kinase Activity = 31 2. 3. Results = 32 2. 4. Discussion = 46 2. 5. Bibliographies = 53 Chapter Ⅲ. TIS21/BTG2/PC3 is Expressed through PKC-d Pathway and Inhibits Binding of Cyclin B1-Cdc2 and Its activity, Independent of p53 Expression = 61 3. 1. Introduction = 62 3. 2. Materials and methods = 64 3. 2. 1. Cell Culture and Treatment with PKC Activator and Inhibitor = 64 3. 2. 2. Northern Blot and RT-PCR Analyses = 65 3. 2. 3. cDNA Construct and Transfection of U937 Cells = 66 3. 2. 4. Synchronization and Assessment of Cell Cycle Phases = 67 3. 2. 5. Caspase Activity Assay = 68 3. 2. 6. Immunoblot Analyses = 68 3. 2. 7. In vitro Assay of Cyclin B1-Associated Kinase Activity = 69 3. 2. 8. Preparation of GST-TIS21 Protein = 70 3. 2. 9. Co-Immunoprecipitation = 71 3. 2. 10. GST Pull Down Assay = 71 3. 3. Results = 72 3. 4. Discussion = 87 3. 5. Bibliographies = 94 국문요약 = 101-
dc.language.isoeng-
dc.publisherThe Graduate School, Ajou University-
dc.rights아주대학교 논문은 저작권에 의해 보호받습니다.-
dc.titleInhibition of Cell Division Cycle by Overexpression of TIS21/BTG2/PC3-
dc.title.alternativeTIS21/BTG2/PC3 과발현에 의한 세포분열주기 억제 기전-
dc.typeThesis-
dc.contributor.affiliation아주대학교 일반대학원-
dc.contributor.alternativeNameRyu, Min Sook-
dc.contributor.department일반대학원 이학계열-
dc.date.awarded2005. 2-
dc.description.degreeMaster-
dc.identifier.localId564287-
dc.identifier.urlhttp://dcoll.ajou.ac.kr:9080/dcollection/jsp/common/DcLoOrgPer.jsp?sItemId=000000000187-
dc.description.alternativeAbstractTIS21 (TPA inducible sequences 21), antiproliferative gene, has been known as one of the early growth response genes and isolated from SW3T3 cells treated with TPA. TPA-induced TIS21 mRNA expression is rapid and transient. TIS21 homologous genes are PC3 in rat PC12 cells and BTG2 (B-cell translocation gene 2) in human. 293 cells that constitutively expressed TIS21 protein were first made to determine how TIS21 inhibits growth. The constitutive TIS21 expresser lines C9 and C11 grew to a lower saturation density than did those in the vector-transfected clones (V7 and V10) and antisense-transfected clones (AS1 and AS4), and the size of the C9 and C11 cells increased significantly after transfection with TIS21 cDNA. The serum-stimulated cell cycle was analyzed by fluorescence-activated cell sorting after double thymidine treatment; V10 progressed normally through the cell division cycle, but C9 and C11 cells accumulated continuously in G1 phase until 36 h after treatment. On the other hand, the progression of cells that had already entered to S or G2/M phase was not inhibited. When cell-cycle regulatory proteins were measured, C9 and C11 cells showed significantly reduced synthesis of Cyclin E and Cyclin-dependent kinase (Cdk) 4 as well as a decrease in Cyclin E-associated Cdk activity. Based on the observations, it was conclude that TIS21 overexpression in 293 cells decreased the amounts of Cyclin E and Cdk4, thereby decreasing the activity of Cdks at the G1-S transition. A new function of TIS21 was also investigated in p53 null U937 cells. Expression of TIS21 by 12-Ο-tetradecanoyl phorbol-13-acetate (TPA) stimulation was mediated by PKC-δ activation, however, was strongly inhibited by cPKC isozymes. When U937 cells were treated with TPA+Go6976, but not TPA+Go6850, the level of TIS21 mRNA was maintained over that of TPA alone. When analyzed by FACS, TPA-induced G2/M arrest was significantly inhibited by Go6850, but not by Go6976, suggesting the involvement of TIS21 and nPKC isozymes. Indeed, PKC-δ was found to be a regulator of the G2/M arrest and TIS21 expression, confirmed by employing rottlerin and dnPKC-δ experiments. In vivo accumulation of TIS21 protein significantly induced cell death through caspase 3 activation, which was supported further by degradations of procaspase 3, full length PKC-δ, pRb and p21^(Waf1) in TIS21?C-terminal deletion mutant expresser. When the cells were synchronized by nocodazole, TIS21 overexpressers inhibited degradations of Cyclin A and Cyclin B1 in 3 hours after release from the synchronization. Furthermore, TIS21 inhibited Cyclin B1-Cdc2 binding and its kinase activity in vivo. In summary, TPA-induced TIS21 mRNA expression is mediated by PKC-δ, and TIS21 induces G2/M arrest and cell death by inhibiting Cyclin B1-Cdc2 binding and the kinase activity through its binding to Cdc2.-
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