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http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/65635Full metadata record
| ???org.dspace.app.webui.jsptag.ItemTag.dcfield??? | Value | Language |
|---|---|---|
| dc.contributor.advisor | 鄭永銘 | |
| dc.contributor.author | Yu-Jing Jiang | en |
| dc.contributor.author | 江鈺菁 | zh_TW |
| dc.date.accessioned | 2021-06-16T23:55:18Z | - |
| dc.date.available | 2012-09-18 | |
| dc.date.copyright | 2012-09-18 | |
| dc.date.issued | 2012 | |
| dc.date.submitted | 2012-07-19 | |
| dc.identifier.uri | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/65635 | - |
| dc.description.abstract | 雌性激素受體(ER)在人類乳癌中扮演極重要的角色。LEF1是調控Wnt/β-catenin路徑的轉錄因子，然而，其對於癌症的調控機制尚未清楚。根據組織免疫染色的結果，我們發現LEF1通常表現於婦科疾病之相關腫瘤且在乳癌中其表現與ER相關。乳癌與卵巢癌細胞株在給予estradiol(E2)處理後會誘導LEF1的表現。當另外又施予ER抑制劑Tamoxifen後則將抑制其表現。欲進一步探討 ER與LEF1路徑之間的關係，我們利用shRNA敲減LEF1，發現ER的表現量也大幅降低。細胞增生率分析和細胞培養軟瓊脂膠試驗更證實了LEF1對於ER陽性乳癌細胞株的生長是必要的，而ER陰性的乳癌細胞株的生長則不受到LEF1的影響。除此之外，我們也發現為ER所調控的基因PR和GREB1會因LEF1被敲減而有表現量減少的現象。我們的研究顯示，LEF1可藉由調控ER路徑進而影響ER陽性之乳癌的增生。 | zh_TW |
| dc.description.abstract | Estrogen receptor-alpha (ERα) is a key factor in the development of breast cancer in human. Lymphoid-enhancing factor 1 (LEF1) is a transcription factor mediating Wnt/β-catenin signaling. However, the role of LEF1 in cancer is still poorly characterized. By immunohistochemistry, we found that LEF1 is frequently expressed in tumors of female genital organs and expression of LEF1 is strongly associated with ER positivity in breast cancer. Treatment of the breast cancer and ovarian cancer cell lines with estradiol (E2) induced LEF1 expression. The induction was abolished by treatment with ER inhibitor tamoxifen. To further elucidate the relationship between ER and LEF1 pathways, we knocked down the expression of LEF1 by shRNA in MCF7 cells and found the expression of ER is dramatically reduced. Using MTT assay and soft agar colony forming assay, we found LEF1 is essential for the growth of ER-positive breast cancer cell lines, whereas the growth of ER-negative breast cancer cell lines was not affected by knockdown of LEF1. In addition, we found the expression levels of estrogen-responsive genes, PR and GREB1, were reduced by knockdown of LEF1. Our study suggests LEF1 is essential for proliferation of ER-positive breast cancer by regulate ER pathway. | en |
| dc.description.provenance | Made available in DSpace on 2021-06-16T23:55:18Z (GMT). No. of bitstreams: 1 ntu-101-R99444002-1.pdf: 2020980 bytes, checksum: 7808af548c1a1818c2fa2fefb7e2afd4 (MD5) Previous issue date: 2012 | en |
| dc.description.tableofcontents | 口試委員審定書 I
中文摘要 II Abstract III Contents IV 1. Introduction 1 1.1 Breast cancer 1 1.2 Genetic changes of breast cancer 2 1.3 Wnt signaling and breast cancer 3 1.4 Estrogen receptor and 17β-estradiol 4 1.5 The structure of estrogen receptor 5 1.6 Phosphorylation of estrogen receptors 6 1.7 Estrogen receptor signaling pathway 7 1.8 The role of estrogen receptor in breast cancer 10 1.9 Treatment of ER-positive breast cancer 11 1.10 Lymphoid enhancer factor 13 1.11 The study aim 14 2. Materials and Methods 15 2.1 Cell culture 15 2.2 RNA interference 15 2.3 Immunochemical stain 16 2.4 RNA isolation 17 2.5 RT-PCR 17 2.6 Western blot 18 2.7 Protein half-life measurement 20 2.8 Luciferase reporter assay 20 2.9 MTT assay 21 2.10 Anchorage-independent growth assay 22 2.11 Immunofluorescence staining 22 3. Results 24 3.1 LEF1 is overexpressed in breast, ovarian, and endometrial cancers 24 3.2 Induction of LEF1 expression by estrogen receptor 25 3.3 Tamoxifen blocks the induction of LEF1 by estrogen 25 3.4 Estrogen directly induces LEF1 expression 25 3.5 Knockdown of LEF1 attenuate proliferation of ER-positive breast cancer cells 26 3.6 Knockdown of LEF1 reduces the ability of anchorage-independent growth 27 3.7 ER protein level is also regulated by LEF1 27 3.8 ER pathway is activated by LEF1 28 3.9 The half-life of ER protein is affected by LEF1 28 3.10 Colocalization of LEF1 and ER in MCF7 cell 29 3.11 Identification of LEF1-dependent estrogen-responsive growth regulatory genes 29 4. Discussion 30 4.1 The expression of LEF1 in breast cancer 30 4.2 Estradiol induced LEF1 expression by direct interaction 31 4.3 LEF1 promotes the proliferation of breast cancer cells 32 4.4 Wnt signaling in regulating ER function in breast cancer 33 4.5 Both PR and GREB1 are the LEF1-dependent estrogen-responsive growth regulatory genes. 35 5. Figures and Tables 38 Figure 1. Immunohistochemical detection of LEF1 in gynecologic tissues and cancer 38 Figure 2. Immunohistochemical detection of LEF1 in breast cancer 39 Figure 3. LEF1 expression correlated with better survival in breast cancer patients in Kaplan-Meir analysis 41 Figure 4. Microarray database analysis showed LEF1 mRNA expression is positive correlated with the level of ER mRNA in breast cancer 42 Figure 5. Western blot and RT-PCR were uesd to prove the expression of LEF1 is induced by estrogen 43 Figure 6. LEF1 RNA level induced by estrogen was not affected by CHX 45 Figure 7. Knockdown of LEF1 reduced cell proliferation 46 Figure 8. Knockdown of LEF1 reduces the ability of anchorage-independent growth 48 Figure 9. Knockdown of LEF1 dramatically reduced the expression of ER. 50 Figure 10. Luciferase assay showed ER pathway is activated by LEF1 51 Figure 11. The half-life of ER is shortened by knockdown of LEF1 52 Figure 12. Colocalization of LEF1 and ER 54 Figure 13. To identify LEF1-dependent estrogen-responsive growth regulatory genes by western blot 55 Table 1. Correlation of LEF1 expression and clinicopathological factors in patients with breast cancer 40 6. Reference 56 | |
| dc.language.iso | en | |
| dc.title | LEF1在乳癌中藉由調控ERα促進其腫瘤生長 | zh_TW |
| dc.title | LEF1 promotes tumor proliferation by regulating ERα in breast cancer. | en |
| dc.type | Thesis | |
| dc.date.schoolyear | 100-2 | |
| dc.description.degree | 碩士 | |
| dc.contributor.oralexamcommittee | 許金玉,張正琪,連晃駿 | |
| dc.subject.keyword | 乳癌,ERα,LEF1, | zh_TW |
| dc.subject.keyword | breast cancer,ERα,LEF1, | en |
| dc.relation.page | 71 | |
| dc.rights.note | 有償授權 | |
| dc.date.accepted | 2012-07-19 | |
| dc.contributor.author-college | 醫學院 | zh_TW |
| dc.contributor.author-dept | 病理學研究所 | zh_TW |
| Appears in Collections: | 病理學科所 | |
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| File | Size | Format | |
|---|---|---|---|
| ntu-101-1.pdf Restricted Access | 1.97 MB | Adobe PDF |
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