No description available.

Derivatives of the quinoline moiety have been shown to exert a range of biological activities, including anti-neoplastic activity. The clinical application of quinoline derivatives in the treatment of malignancies has been limited due to non-selectivity. Four novel hydroxyquinoline derivatives were synthesised as potential anticancer agents. Each of these compounds contains the characteristic quinoline nucleus: a heterocyclic moiety containing a nitrogen atom. A hydroxyl group is present on C-8 and an azo bond links the heterocyclic quinoline core to a monocyclic benzene ring with various substituents. The aim of this study was to investigate the potential anticancer properties of the four hydroxyquinolines as pertains to their in vitro cytotoxicity, ability to circumvent multidrug resistance and possible mechanism of action. The acute in vivo toxicity profile of the two most promising compounds was also investigated. The tumour specificity of a compound is an indicator of the selective cytotoxicity of a compound towards cancer cells, while maintaining minimal toxicity towards normal cells. To this end the four hydroxyquinolines were screened on a range of commercially available cancer cell lines and primary (normal) cultures. The cancer cell lines used included human cervical adenocarcinoma (HeLa), human estrogen receptor positive breast cancer (MCF-7) and several resistant cancer cell lines. Chicken embryo fibroblasts and human lymphocytes were included as primary cell cultures. From the results the cancer cell lines most sensitive to each compound were identified: breast (MCF-7) and leukaemia (Jurkat) cells were most sensitive to HQ5, a resistant colon cancer cell line (COLO 320DM) was most susceptible to HQ6 and HQ7, and HQ10 was most effective against cervical cancer (HeLa). Data indicated that HQ5 and HQ10 displayed the highest tumour specificities and these two promising hydroxyquinoline derivatives were selected for further investigation. As quinoline derivatives have been reported to modulate multidrug resistance through the inhibition of the P-glycoprotein (P-gp) efflux pump, the effect of HQ5 and HQ10 on P-gp was evaluated in two experimental models. Firstly the experimental hydroxyquinolines were used in combination with the P-gp substrates doxorubicin, vinblastine and paclitaxel on three P-gp expressing cell lines to ascertain whether a synergistic combination could be observed. Secondly the direct effect of HQ5 and HQ10 on the function of P-gp was determined through the rhodamine 123 retention assay. According to the results obtained from the combination therapy, the combinations of the experimental compounds and the known chemotherapeutic agents tested were at most additive. Data obtained from the rhodamine 123 accumulation assay revealed that HQ5 and HQ10 did not inhibit P-gp in the three P-gp expressing cell lines tested but appeared to enhance P-gp activity. The mechanism of action of the two selected hydroxyquinolines was further investigated through flow cytometric analysis. The effect of HQ5 and HQ10 on the induction of apoptosis or necrosis in MCF-7 cells was determined. Results indicated that the two experimental compounds induced apoptosis in a dose and time dependent manner. After investigating the effect of the hydroxyquinolines on the cell cycle progression of MCF-7 cells, it was observed that HQ5 and HQ10 arrested the cell cycle at the G1 checkpoint. Results suggest that at higher concentrations of HQ5 inhibition resembled a G2 inhibitor. In an acute in vivo cytotoxicity study the tolerability and safety profile of HQ5 and HQ10 were investigated. After daily intraperitoneal administration of either of the two compounds at two concentrations, no obvious histological signs of toxicity were reported. However a dose of 2 mg/kg per day of HQ10 caused a significant reduction in body weight. Haematological analysis revealed that administration of 0.1 mg/kg of HQ5 resulted in a significant decrease in white cell count. No other haematological parameters studied showed any difference between the animals in the control and experimental groups. It was thus concluded that daily dosing of HQ5 and HQ10 was well-tolerated and caused no severe toxicity. Chronic in vivo toxicity profiles were not determined in this study. The in vitro studies suggested that HQ5 and HQ10 displayed promising anticancer properties. However, further investigation revealed several unfavourable characteristics, with regards to the solubility, purity and stability of these experimental hydroxyquinolines. In addition in vivo studies added further doubt on the success of these compounds in a clinical setting and it was concluded that these compounds were unsuitable for further development. Copyright / Dissertation (MSc)--University of Pretoria, 2011. / Pharmacology / unrestricted

Despite being the most preventable cancer, cervical cancer remains the third leading cause of cancer death worldwide. Over 85% of cervical cancer incidence and mortality occurs in low-resource countries where screening programs for early detection are either inadequate or unavailable. In the developed world, where screening programs are well organized, incidence and mortality rates are greatly reduced. Recent advances in optical imaging have the potential to enable cervical cancer screening at the point-of-care, even in the hands of less experienced providers. High performance optical imaging systems can be constructed at relatively low cost, and image analysis can be automated; thus, these technologies may provide a way to bridge the gap to cervical cancer screening for developing countries. This work focuses on the design, construction, and clinical testing of a novel multimodal optical imaging (combination of wide-field imaging and high-resolution) for early detection of cervical neoplasia. The Multimodal Digital Imager (MDI) acquires in vivo images of cervical tissue in fluorescence, narrow band reflectance, and orthogonal polarized reflectance modes using multiple illumination wavelengths. The High Resolution Microendoscope (HRME) was used to interrogate clinically suspicious areas with subcellular spatial resolution, revealing changes in nuclear to cytoplasmic area ratio. In vivo image data from the wide-field system was combined with image data from a high- resolution microendoscope (HRME) in order to test the effectiveness of the multimodal optical imaging in discriminating between cervical neoplasia and non-neoplastic. Multimodal optical imaging coupled with computer aided diagnostic achieved a sensitivity of 82% and specificity of 85% for discriminating cervical neoplastic from non-neoplastic This work has demonstrated that multimodal optical imaging; combination of wide-field and high-resolution optical imaging of the cervix can assist in the detection of cervical neoplasia and can be implemented effectively in a low-resource setting.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2009.

Diss. (sammanfattning) Stockholm : Karol. inst., 2005. / Härtill 6 uppsatser.

Tang, Ho Lam. / "December 2010." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 119-132). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

by Wai Ching Wa, Gina. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1990. / Bibliography: leaves 303-314. / Chapter 1. --- INTRODUCTION --- p.1 / Chapter 2. --- LITERATURE REVIEW ON CERVIX UTERI / Chapter 2.1 --- HISTOLOGY OF CERVIX UTERI --- p.4 / Chapter 2.2 --- CYTOLOGY OF CERVIX UTERI --- p.5 / Chapter 2.3 --- CERVICAL EPITHELIAL LESIONS / Chapter 2.3.1 --- Squamous Metaplasia --- p.7 / Chapter 2.3.2 --- Cervical Intraepithelial Neoplasia --- p.9 / Chapter 2.3.3 --- Viral Infections --- p.17 / Chapter 2.4 --- DIAGNOSTIC APPROACH TO CERVICAL LESIONS --- p.20 / Chapter 2.5 --- DIAGNOSTIC VARIABILITY OF CERVICAL LESIONS --- p.21 / Chapter 2.6 --- IMPORTANCE OF CERVICAL CARCINOMA IN HONG KONG --- p.21 / Chapter 3. --- LITERATURE REVIEW ON NASOPHARYNX / Chapter 3.1 --- HISTOLOGY OF NASOPHARYNX --- p.22 / Chapter 3.2 --- CYTOLOGY OF NASOPHARYNX --- p.24 / Chapter 3.3 --- NASOPHARYNGEAL EPITHELIAL LESIONS / Chapter 3.3.1 --- 'Squamous Metaplasia' --- p.25 / Chapter 3.3.2 --- Nasopharyngeal Intraepithelial Neoplasia --- p.26 / Chapter 3.3.3 --- Viral Infections --- p.27 / Chapter 3.4 --- DIAGNOSTIC APPROACH TO NASOPHARYNGEAL LESIONS --- p.28 / Chapter 3.5 --- IMPORTANCE OF NASOPHARYNGEAL CARCINOMA IN HONG KONG --- p.29 / Chapter 4. --- LITERATURE REVIEW ON MORPHOMETRY / Chapter 4.1 --- QUANTITATIVE ASSESSMENT OF CELL FEATURES --- p.30 / Chapter 4.2 --- TERMINOLOGY --- p.31 / Chapter 4.3 --- APPROACHES TO SAMPLING --- p.32 / Chapter 4.4 --- SOURCES OF VARIATION --- p.32 / Chapter 4.5 --- METHODOLOGY FOR MORPHOMETRY --- p.33 / Chapter 4.6 --- FEATURES FOR MORPHOMETRY IN INTRAEPITHELIAL NEOPLASIA --- p.35 / Chapter 4.7 --- PREVIOUS MORPHOMETRIC STUDIES ON INTRAEPITHELIAL NEOPLASIA --- p.36 / Chapter 5. --- MATERIALS AND METHODS / Chapter 5.1 --- MATERIALS / Chapter 5.1.1 --- Cervix Uteri --- p.41 / Chapter 5.1.2 --- Nasopharynx --- p.41 / Chapter 5.2 --- METHODS / Chapter 5.2.1 --- Equipment --- p.42 / Chapter 5.2.2 --- Pilot Study for Reproducibility --- p.43 / Chapter 5.2.3 --- Estimation of Minimum Sample Size --- p.43 / Chapter 5.2.4 --- Morphometric Procedures --- p.44 / Chapter 5.2.5 --- Statistical Analysis --- p.48 / Chapter 5.2.6 --- Comparison of Visual Diagnosis of Cervical smears and biopsies --- p.49 / Chapter 5.2.7 --- Survey of Subjective Assessment Criteria for Cervical Biopsies and Smears --- p.50 / Chapter 6. --- RESULTS / Chapter 6.1 --- PILOT STUDY / Chapter 6.1.1 --- Intraobserver Reproducibility --- p.52 / Chapter 6.1.2 --- Minimum Sample Size --- p.52 / Chapter 6.2 --- CERVIX / Chapter 6.2.1 --- Maturation Sequence of Cervical Epithelium --- p.53 / Chapter 6.2.2 --- Differences of Morphometric Means between various groups of Cervical Biopsies --- p.56 / Chapter 6.2.3 --- Discriminant Analysis of Cervical Biopsies --- p.58 / Chapter 6.2.4 --- Differences of Morphometric Means between various groups of Cervical Smears --- p.60 / Chapter 6.2.5 --- Discriminant Analysis of Cervical Smears --- p.61 / Chapter 6.2.6 --- Comparison of Cervical Smears and Biopsies --- p.62 / Chapter 6.2.7 --- Subjective Assessment Criteria for Cervical Biopsies and Smears --- p.63 / Chapter 6.3 --- NASOPHARYNX / Chapter 6.3.1 --- Maturation Sequence of Nasopharyngeal Epithelium --- p.65 / Chapter 6.3.2 --- Differences of Morphometric Means between various groups of Nasopharyngeal Biopsies --- p.68 / Chapter 6.3.3 --- Discriminant Analysis of Nasopharyngeal Biopsies --- p.70 / Chapter 6.4 --- COMPARISON OF CERVIX UTERI AND NASOPHARYNX --- p.71 / Chapter 7. --- DISCUSSION / Chapter 7.1 --- CERVIX UTERI / Chapter 7.1.1 --- Maturation Sequence --- p.73 / Chapter 7.1.2 --- Discrimination of different groups in Biopsies --- p.76 / Chapter 7.1.3 --- Discrimination of different groups in Smears --- p.77 / Chapter 7.1.4 --- Comparison of Smears and Biopsies --- p.78 / Chapter 7.1.5 --- Subjective Assessment Criteria --- p.80 / Chapter 7.1.6 --- Future directions --- p.81 / Chapter 7.2 --- NASOPHARYNX / Chapter 7.2.1 --- Maturation Sequence --- p.81 / Chapter 7.2.2 --- Discrimination of different groups --- p.84 / Chapter 7.2.3 --- Nasopharyngeal Cytology --- p.84 / Chapter 7.2.4 --- Future directions --- p.85 / Chapter 7.3. --- COMPARISON OF CERVIX UTERI AND NASOPHARYNX / Chapter 7.3.1 --- Morphometric data --- p.85 / Chapter 7.3.2 --- Discriminant Analysis --- p.87 / Chapter 8. --- CONCLUSIONS --- p.89 / Chapter APPENDIX A --- Survey of subjective assessment criteria for cervical biopsies and smears / Tables A1-A7 --- p.92 / Chapter APPENDIX B --- Results of pilot study / Tables B1-B6 --- p.100 / Chapter APPENDIX C --- Morphometric data and results of statistical tests for cervical biopsies / Fig. C1-C61 --- p.104 / Tables C1-C19 --- p.166 / Chapter APPENDIX D --- Morphometric data and results of statistical tests for cervical smears / Fig. D1-D2 6 --- p.179 / Tables D1-D3 --- p.206 / Chapter APPENDIX E --- Comparison of cervical smears and biopsies / Tables E1-E3 --- p.208 / Chapter APPENDIX F --- Morphometric data and results of statistical tests for nasopharyngeal biopsies / Fig. F1-F61 --- p.211 / Tables F1-F12 --- p.273 / Chapter APPENDIX G --- Comparison of nasopharyngeal and cervical biopsies / Tables G1-G15 --- p.282 / Chapter APPENDIX H --- Pictures of materials and equipment / Fig. H1-H21 --- p.291 / REFERENCES --- p.303

鈣粘蛋白是一類通過影響細胞粘附和細胞信號通路在腫瘤發生中起重要作用的細胞間粘附分子。鈣粘蛋白超家族包括經典鈣粘蛋白和非經典鈣粘蛋白，其中非經典鈣粘蛋白包含了原鈣粘蛋白。啟動子CpG甲基化調控下的基因沉默或表達下調是腫瘤發生中一個關鍵事件的觀點現已得到廣泛認可。一些鈣粘蛋白家族成員，如鈣粘蛋白-1/4/13（CDH1，CDH4，CDH13）被已有研究報導是受擬遺傳學調控沉默的功能性腫瘤抑制基因。本研究主要針對兩個鈣粘蛋白家族成員鈣粘蛋白-11（CDH11）和原鈣粘蛋白-10（PCDH10）進行腫瘤發生相關功能和機制的研究。 / CDH11位於雜合性缺失（LOH）經常發生而預示可能存在抑癌基因的染色體16q21-22區域，我們實驗室先前通過基因組芯片雜交技術（aCGH）對腫瘤細胞系的研究已發現它是該區域一個可能的抑癌基因。我們通過進一步的半定量反轉錄聚合酶鏈反應（RT-PCR）發現CDH11在正常組織和永生化正常上皮細胞中廣泛表達，但在各腫瘤細胞系中表達下降。甲基化特異性聚合酶鏈反應（MSP）和亞硫酸氫鹽處理的基因組測序（BGS）檢測到CDH11啟動子甲基化常發生于腫瘤細胞和腫瘤組織中。在CDH11表達缺失的腫瘤細胞中重新導入該基因的表達可顯著減少細胞克隆的形成，誘導細胞凋亡并抑制腫瘤細胞的遷移。通過更深入的機制研究，我們發現CDH11通過抑制Wnt/β-catenin信號通路發揮功能。 / 本研究的另一個鈣粘蛋白家族成員是PCDH10。之前我們實驗室的工作已經證實了PCDH10是一個在鼻咽癌和食管癌中受啟動子甲基化調控的抑癌基因,這裡我們主要研究它在大腸癌發病中的功能和機制。我們發現在PCDH10表達缺失的大腸癌細胞中重新導入PCDH10表達可顯著抑制腫瘤細胞的克隆形成，細胞遷移和幹細胞性。機制研究顯示PCDH10抑制Wnt/β-catenin和RhoA信號轉導通路，并進一步抑制腫瘤上皮細胞-間充質轉化（EMT）的過程，誘導幹細胞標記的下調。 / 綜上所述，本研究顯示CDH11和PCDH10兩個鈣粘蛋白家族成員在多種腫瘤中廣泛受甲基化調控失活，它們是重要的Wnt/β-catenin信號通路拮抗因素，可抑制腫瘤細胞的克隆形成和細胞遷移 / Cadherins are an important group of cell-cell adhesion molecules, which play crucial roles in tumorigenesis by affecting cell adhesion and cell signaling. Cadherin superfamily consists of classical cadherins and non-classical cadherins including protocadherins. It has been well recognized that silencing or downregulation of tumor suppressor genes (TSGs) by promoter CpG methylation is a critical event in human tumorigenesis. Some cadherin family members, such as CDH1, CDH4, CDH13, have been reported as functional TSGs silenced through epigenetic regulation. In this study, I mainly focus on the function and mechanism studies of two cadherin members-Cadherin 11(CDH11) and Protocadherin 10 (PCDH10). / CDH11 is located in 16q21-22, a region with frequent loss of heterozygosity (LOH), indicating the presence of candidate TSG. Previously, our lab also identified CDH11 as a candidate TSG through array-CGH of tumor cell lines. I further found by semi-quantitative RT-PCR that CDH11 was broadly expressed in normal tissues while frequently downregulated in multiple tumor cell lines, but not in immortalized normal epithelial cells. Methylation-specific PCR (MSP) and bisulfite genomic sequencing (BGS) detected frequent promoter methylation of CDH11 in tumor cell lines and primary tumor samples. Ectopic expression of CDH11 dramatically reduced tumor cell clonogenecity, induced tumor cell apoptosis and inhibited tumor cell migration. By further mechanism study, I found that CDH11 is a negative inhibitor of Wnt/β-catenin signaling pathway. / Another cadherin family protein which I chose to study is PCDH10. Previously our lab identified PCDH10 as a TSG by promoter methylation in nasopharyngeal and esophageal carcinomas. I studied the function and mechanism of PCDH10 in the pathogenesis of colon cancer. I found ectopic expression of PCDH10 strongly suppressed colon tumor cell clonogenecity, migration and stemness. Moreover, I found that PCDH10 repressed Wnt/β-catenin and RhoA signaling, thus further inhibited the epithelial-to-mesenchymal transition (EMT) of tumor cells and downregulated stem cell markers. / In summary, this study demonstrates two cadherin family members CDH11 and PCDH10, as important antagonists to Wnt/β-catenin signaling pathway, suppress tumor cell clonogenecity, migration, and are also frequently inactivated by epigenetic mechanism in multiple tumors. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Zhang, Yanjiao. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 84-95). / Abstracts also in Chinese. / Abstract --- p.i / Acknowledgements --- p.iii / Table of Contents --- p.vi / List of Tables --- p.x / List of Figures --- p.xi / List of Abbreviations --- p.xiii / List of Publications --- p.xvi / Chapter Chapter 1 --- Introduction and Literature Review --- p.1 / Chapter 1.1 --- Cancer --- p.1 / Chapter 1.1.1 --- General introduction about cancer --- p.1 / Chapter 1.1.2 --- Oncogenes and TSGs --- p.3 / Chapter 1.1.3 --- Cancer mechanism models --- p.3 / Chapter 1.2 --- Cancer Epigenetics --- p.5 / Chapter 1.2.1 --- DNA methylation --- p.6 / Chapter 1.2.2 --- DNA methylation and gene silencing --- p.7 / Chapter 1.2.3 --- DNA methylation and cancer --- p.7 / Chapter 1.2.4 --- Clinical implications of DNA methylation --- p.8 / Chapter 1.3 --- Cadherins --- p.10 / Chapter 1.3.1 --- General introduction of cadherin superfamily --- p.10 / Chapter 1.3.2 --- Cadherin classification --- p.10 / Chapter 1.3.3 --- Cadherin and cancers --- p.12 / Chapter 1.3.4 --- Cadherin switch and EMT in cancer --- p.16 / Chapter 1.4 --- Wnt/β-catenin signaling pathway and cancer --- p.16 / Chapter 1.4.1 --- Wnt/β-catenin signaling pathway --- p.16 / Chapter 1.4.2 --- Wnt/β-catenin signaling pathway in cancer --- p.18 / Chapter 1.4.3 --- Epigenetic silencing of Wnt/β-catenin signaling --- p.20 / Chapter 1.4.4 --- Wnt/β-catenin signaling pathway in CRC --- p.21 / Chapter Chapter 2 --- Aims of the Study --- p.22 / Chapter Chapter 3 --- Materials and Methods --- p.25 / Chapter 3.1 --- Cell lines and tissue samples --- p.25 / Chapter 3.1.1 --- Cell lines --- p.25 / Chapter 3.1.2 --- Maintenance of cell lines --- p.25 / Chapter 3.1.3 --- Drug treatment of cell lines --- p.26 / Chapter 3.1.4 --- Normal and primary tissues --- p.26 / Chapter 3.1.5 --- Total RNA extraction --- p.27 / Chapter 3.1.6 --- Genomic DNA extraction --- p.28 / Chapter 3.2 --- Gene expression analysis --- p.29 / Chapter 3.2.1 --- Reverse transcription (RT) --- p.29 / Chapter 3.2.2 --- Semi-quantitative RT-PCR --- p.30 / Chapter 3.3 --- Methylation Analysis --- p.32 / Chapter 3.3.1 --- CpG island prediction --- p.32 / Chapter 3.3.2 --- Sodium bisulfite treatment of genomic DNA --- p.33 / Chapter 3.3.3 --- Methylation-specific PCR (MSP) --- p.33 / Chapter 3.3.4 --- Bisulfite Genomic Sequencing (BGS) --- p.34 / Chapter 3.4 --- Construction of expression plasmids --- p.36 / Chapter 3.4.1 --- Construction of CDH11 expression vector --- p.36 / Chapter 3.4.2 --- Construction of PCDH10 expression plasmid --- p.38 / Chapter 3.4.3 --- Plasmid extraction --- p.39 / Chapter 3.5 --- Plasmid transfection --- p.41 / Chapter 3.6 --- Subcellular localization --- p.42 / Chapter 3.7 --- Function analyses --- p.43 / Chapter 3.7.1 --- Colony formation assay --- p.43 / Chapter 3.7.2 --- Wound healing assay --- p.44 / Chapter 3.8 --- Mechanism exploration --- p.44 / Chapter 3.8.1 --- Protein extraction and western-blot --- p.44 / Chapter 3.8.2 --- Dual-luciferase reporter assay --- p.47 / Chapter 3.9 --- Statistical analysis --- p.48 / Chapter Chapter 4 --- CDH11 functions as a tumor suppressor via modulating Wnt/β-catenin signaling and is frequently downregulated by promoter methylation --- p.49 / Chapter 4.1 --- The CpG island of CDH11 gene promoter --- p.50 / Chapter 4.2 --- CDH11 expression profile in normal tissues --- p.50 / Chapter 4.3 --- Frequent silencing of CDH11 by promoter methylation in multiple tumors --- p.51 / Chapter 4.4 --- Restoration of CDH11 expression by pharmacologic demethylation --- p.53 / Chapter 4.5 --- Frequent CDH11 methylation in primary tumors --- p.54 / Chapter 4.6 --- Function studies --- p.56 / Chapter 4.6.1 --- Ectopic expression of CDH11 inhibited tumor cell clonogenecity --- p.57 / Chapter 4.6.2 --- CDH11 induced tumor cell apoptosis --- p.57 / Chapter 4.6.3 --- CDH11 inhibited tumor cell migration --- p.58 / Chapter 4.7 --- CDH11 antagonized Wnt/β-catenin signaling --- p.59 / Chapter 4.8 --- Discussion --- p.60 / Chapter Chapter 5 --- Epigenetic inactivated tumor suppressor PCDH10 exerts tumor suppressive functions through modulating Wnt/β-catenin signaling and cell stemness in colon cancer --- p.66 / Chapter 5.1 --- PCDH10 was broadly expressed in normal tissues and frequently silenced in CRC cell lines --- p.67 / Chapter 5.2 --- Promoter methylation mediated PCDH10 silencing in CRC cell lines --- p.68 / Chapter 5.3 --- Frequent PCDH10 methylation in CRC primary tumors --- p.69 / Chapter 5.4 --- PCDH10 was located in cytoplasm and membrane --- p.70 / Chapter 5.5 --- Function Studies --- p.71 / Chapter 5.5.1 --- PCDH10 inhibited clonogenicity of tumor cells --- p.71 / Chapter 5.5.2 --- PCDH10 suppressed tumor cell mobility --- p.72 / Chapter 5.6 --- Mechanism exploration of PCDH10 in CRC --- p.72 / Chapter 5.6.1 --- PCDH10 antagonized Wnt/β-catenin signaling --- p.72 / Chapter 5.6.2 --- PCDH10 negatively regulated EMT and stemness of tumor cells --- p.74 / Chapter 5.6.3 --- PCDH10 inhibited RhoA signaling --- p.75 / Chapter 5.7 --- Discussion --- p.75 / Chapter Chapter 6 --- Conclusions and Future studies --- p.80 / Chapter 6.1 --- Conclusions --- p.80 / Chapter 6.2 --- Future studies --- p.82 / Reference List --- p.84

<p>Studying the early stages of cancer can provide important insight into the molecular basis of the disease. In many human cancers, such as prostate, pancreatic, and colon cancer, a pre-neoplastic, or intermediate, stage of the disease has been identified. The pre-neoplastic stage is presumed to be a transition during which normal cells undergo malignant transformation. However, the link between the pre-neoplastic cells and end-stage disease has never been formally established. To investigate the fate of such cells, the patched (ptc) mutant mouse, a model for the brain tumor medulloblastoma was used. Pre-neoplastic cells (PNCs) are found in most ptc mutants during early adulthood, but only 15% of these animals develop tumors. Although PNCs are found in mice that develop tumors, the ability of PNCs to give rise to tumors has never been demonstrated directly, and the fate of cells that do not form tumors remains unknown. Genetic fate mapping and orthotopic transplantation provided definitive evidence that PNCs give rise to tumors and showed that the predominant fate of PNCs that do not form tumors is differentiation. Moreover, N-myc, a gene commonly amplified in medulloblastoma, can dramatically alter the fate of PNCs, preventing differentiation and driving progression to tumors. Importantly, N-myc allows PNCs to grow independently of hedgehog signaling, making the resulting tumors resistant to hedgehog antagonists. These studies provide the first direct evidence that PNCs can give rise to tumors, and demonstrate that identification of genetic changes that promote tumor progression is critical for designing effective therapies for cancer.</p> / Dissertation

Telomerase is a ribonucleoprotein that maintains telomere. It is activated in greater than 85% of human neoplasms. Traditionally, reactivation of telomerase during tumorigenesis was thought to be required solely to impart an indefinite lifespan. Recently, however, several studies have suggested that telomerase may contribute to tumorigenesis via an additional mechanism that is independent of its role in telomere lengthening. We sought to identify the region(s) of hTERT that contribute to this non-classical role of telomerase. We proposed to identify such regions by their ability to impart a tumorigenic phenotype in ALT cells transduced with activated Ras. Also, we attempted to develop methods to demonstrate that this role is not dependant of telomerase localizing to the telomere. The strategies employed and the progress gained toward each goal is presented in this thesis.