Small cell lung cancer (SCLC) is characterized by prompt response to chemotherapy and radiotherapy but relapsing with drug resistance and distant metastasis, leading to poor overall prognosis. New anticancer agents and regimens are drastically needed for SCLC treatment. Arsenic trioxide (ATO), a traditional Chinese medicine used as a poison for thousands of years, has been tested in many hematological and solid cancers both in vitro and in vivo, with promising effects. In order to establish the scientific ground for future clinical application of ATO in SCLC, this study aimed to investigate the anticancer effect and mechanism of ATO in SCLC using in vitro and in vivo models, either as a single agent or in combination with standard chemotherapy. In addition, an ATO-acquired resistant cell line (H841-AR) derived from SCLC cell line H841 was used to explore potential mechanisms of ATO resistance and cross-resistance to other chemotherapeutic drugs. In the first part of this study, ATO was shown to exert cytotoxic effect in all of the chosen SCLC cell lines. Various cellular mechanisms were triggered upon ATO exposure: redox status disturbances (hydrogen peroxide (H2O2) generation, glutathione (GSH) depletion and thioredoxin 1 (Trx1) down-regulation), mitochondrial membrane depolarization (MMD), DNA damage, apoptosis and necroptosis. In concert with this, Bcl-2 was down-regulated accompanied by MMD, release of AIF and SMAC, DNA degradation, XIAP inhibition and caspases activation. Adoption of N-acetyl-L-cysteine (NAC) and buthionine sulfoximine (BSO) demonstrated GSH depletion and reactive oxygen species (ROS) generation played the pivotal role to mediate cytotoxic effect of ATO in SCLC. In the second part of this study, when combined with chemotherapeutic agents, ATO displayed synergistic and antagonistic interaction with cisplatin and etoposide respectively in SCLC cell line models. The beneficial combination of ATO and cisplatin was also substantiated by tumor xenograft models. Augmented GSH depletion and suppressed drug efflux mechanism were found to explain the synergistic effects. In the last part of this study, H841-AR was generated as an acquired multi-drug resistant (ATO, cisplatin and etoposide) cell line to investigate the potential resistance mechanisms and possible future drug combinations. Comparing H841-AR cells with parental H841 cells using cDNA microarray, a long list of genes was altered in ATO-resistant cells. At least 20 up-regulated and 45 down-regulated genes were short-listed as candidates with a cut-off at 5-fold change. Interestingly, qPCR data has shown that 5 selected up-regulated genes in H841-AR cells were also highly expressed in DMS79 cells with intrinsic ATO resistance compared to the relatively sensitive cell lines, indicating that these genes might be associated with ATO resistance in SCLC. In summary, ATO was shown to be an active anticancer agent in SCLC, either alone or in combination with cisplatin. The major mechanisms of action of ATO and its synergism with cisplatin in SCLC were elucidated. Genetic data derived from an acquired resistant (to ATO, cisplatin and etoposide) SCLC cell line may help to uncover the mechanisms of resistance to ATO, allowing possible future drug combinations. / published_or_final_version / Medicine / Doctoral / Doctor of Philosophy

Thesis (doctoral)--Westphalia, 1937.

Thesis (doctoral)--Westphalia, 1937.

Thesis (Ph. D.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains xiv, 133 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 128-133).

Thesis (M. Phil.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

Neste trabalho, foram caracterizados os estados eletrônicos fundamental e excitados de mais baixa energia dos sistemas 1;3[H,C,As]. Para isso, foram empregados vários métodos ab initio de estrutura eletrônica (MP2, CCSD(T), CCSD(T)-F12b e MRCISD) aliados a extensos conjuntos de funções de base consistentes na correlação (aug-cc-pVnZ, em que n = D, T, Q e 5). Buscando uma acurácia ainda maior, os resultados obtidos foram extrapolados para o limite do conjunto de base completa (CBS). O estado X1Σ+ da molécula HCAs e o estado eletrônico fundamental do sistema 1[H,C,As], com as seguintes distâncias internucleares: rHC=1,0748 Å e rCAs=1,6602 Å; para as frequências harmônicas, obtivemos ω1(&#963)=1068 cm-1, ω2(π)/ω3(&#960)= 626 cm-1 e ω4(σ)=3310 cm-1 no nível de teoria CCSD(T)-F12-CBS. A espécie 1Σ+ HAsC e um ponto de sela de segunda ordem sobre a superfície de energia potencial (localizado a 75,24 kcal.mol-1 do X1Σ+ HCAs), ou seja, chegamos a conclusão que esta espécie, neste estado eletrônico, em fase gasosa, não existe. Já para os estados tripletos, ha isomerização, sendo que o 13A\' HCAs e o 13A\' HAsC foram caracterizados como mínimos com uma energia relativa ao mínimo global de 59,27 kcal.mol-1 e 88,22 kcal.mol-1, respectivamente. Além disso, exploramos os canais de dissociação destas espécies no nível de teoria CCSD(T). Foram ainda calculadas as frequências fundamentais para os estados do HCAs e do HAsC, como também investigada a inclusão da correlação dos elétrons do caroço nos parâmetros estruturais, vibracionais e energéticos. Estimamos o calor de formação (ΔH0f) a 0 e 298,15 K para as espécies CH, AsH, CAs e HCAs, sendo que a maioria desses valores ainda não e conhecida na literatura. Para o X1Σ+ HCAs, obtivemos um valor de ΔH0f igual a 71,22 kcal.mol-1 a 0 K e 70,38 kcal.mol-1 a 298,15 K. Calculamos o potencial de ionização da molécula HCAs utilizando varias metodologias teóricas, obtendo valores muito próximos aos experimentais, por exemplo, o CCSD(T)-aVTZ forneceu 9,90 eV frente ao valor experimental de 9,8 eV. Os estados eletrônicos excitados singleto e tripleto das espécies HCAs e HAsC foram também caracterizados com a obtenção de dados estruturais, vibracionais e energéticos. A maioria dos dados das espécies HCAs e HAsC nesta dissertação são inéditos na literatura química. / In this work, the ground state and low-lying excited electronic states of system 1;3[H,C,As] were investigated theoretically. Several ab initio molecular electronic structure theory were employed (MP2, CCSD(T), CCSD(T)-F12b e MRCISD) along with extensive correlation-consistent basis sets (aug-cc-pVnZ, n= T, Q e 5). Seeking increasing accuracy, further extrapolation of the results to the complete-basis-set (CBS) limit were carried out. The ground electronic state of 1[H,C,As] is the 1Σ+ HCAs specie, with internuclear distances of rHC=1.0748 Å and rCAs=1.6602 Å, and with harmonic vibrational frequencies ω1(&#963)=1068 cm-1, ω2(π)/ω3(&#960)= 626 cm-1 ω4(σ)=3310 cm-1, at the CCSD(T)-F12-CBS level theory. The electronic state 1Σ+ HAsC is a second-order saddle point on the potential energy surface (located at 75.24 kcal.mol-1 above HCAs), thus providing evidence that this species does not exist in gas phase. However, there is isomerization for triplet electronic states 13A\' HCAs to 13A\' HAsC, with energy relative to global minimum of 59,27 kcal.mol-1 e 88,22 kcal.mol-1, respectively. Fundamental frequencies and the effects of correlation of core electrons in structural, vibrational, and energetic parameters were also evaluated for HCAs and HAsC. Furthermore, the dissociation channels of these species were also evaluated at the CCSD(T)-CBS level theory. The heats of formations (ΔH0f), at 0 and 298,15 K, for the species CH, AsH, CAs and HCAs, were estimated; for most of them these results are inexistent in the literature. For X1Σ+ HCAs, we obtained 71.22 kcal.mol-1 at 0 K and 70.38 kcal.mol-1 at 298.15 K for ΔH0f. The ionization potential was also calculated by several theoretical methodologies, and the results are close to the experimental data; using CCSD(T)-aVTZ, we predicted a value of 9,9 eV, in close agreement with experimental value of 9,8 eV. The singlet and triplet electronic excited states of HCAs and HAsC were investigated and their structural, vibrational and energetic properties evaluated. Most of the results of this work are new in the chemistry literature.

published_or_final_version / abstract / Medicine / Master / Master of Philosophy

published_or_final_version / Paediatrics and Adolescent Medicine / Master / Master of Philosophy

No description available.

Zhou, Linli. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 108-118). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / 論文摘要 --- p.iv / Abbreviations --- p.v / List of Figures --- p.vii / List of Tables --- p.ix / Table of Contents --- p.x / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Breast Cancer --- p.1 / Chapter 1.1.1 --- Introduction to Breast Cancer --- p.1 / Chapter 1.1.2 --- Types of Breast Cancer --- p.3 / Chapter 1.1.3 --- Epidemiologic Risk Factors and Etiology --- p.4 / Chapter 1.2 --- Estrogen and Breast Cancer --- p.7 / Chapter 1.3 --- Estrogen Receptor --- p.9 / Chapter 1.4 --- Current Treatment of Breast Cancer --- p.10 / Chapter 1.4.1 --- Chemotherapy --- p.10 / Chapter 1.4.2 --- Hormonal (Anti-Estrogen) Therapy --- p.11 / Chapter 1.4.2.1 --- Tamoxifen and Other Anti-estrogens --- p.12 / Chapter 1.4.2.2 --- Disadvantages of Tamoxifen --- p.13 / Chapter 1.5 --- Arsenic Trioxide --- p.14 / Chapter 1.5.1 --- The Characteristics of Arsenic Trioxide (AS2O3) --- p.14 / Chapter 1.5.2 --- The Medical use of Arsenic Trioxide (As2O3) --- p.16 / Chapter 1.5.3 --- Arsenic Trioxide (As2O3) in treating Acute Promyelocytic Leukemia (APL) --- p.17 / Chapter 1.5.3.1 --- Acute Promyelocytic Leukemia (APL) --- p.17 / Chapter 1.5.3.2 --- All-trans Retinoic Acid (ATRA) Treatment of APL --- p.18 / Chapter 1.5.3.3 --- Clinical Trial of the Arsenic Trioxide on APL --- p.19 / Chapter 1.5.3.4 --- In vitro and in vivo Study of Arsenic Trioxide (As2O3) in treating APL --- p.19 / Chapter 1.5.3.5 --- Common Side Effects of Arsenic Trioxide (As2O3) on APL --- p.21 / Chapter 1.5.4 --- Anti-cancer effect of Arsenic Trioxide on other cancers --- p.23 / Chapter 1.6 --- Aim of Study --- p.24 / Chapter Chapter 2 --- Materials and Methods --- p.26 / Chapter 2.1 --- Materials --- p.27 / Chapter 2.1.1 --- Cell Lines and Culture Medium --- p.27 / Chapter 2.1.1.1 --- Cell Lines --- p.27 / Chapter 2.1.1.2 --- Culture Medium --- p.27 / Chapter 2.1.2 --- Chemicals --- p.28 / Chapter 2.1.3 --- Buffers and Reagents --- p.29 / Chapter 2.1.4 --- Reagents for MTT Assay --- p.30 / Chapter 2.1.5 --- Reagents for DNA Fragmentation --- p.31 / Chapter 2.1.5.1 --- Reagents for DNA Extraction --- p.31 / Chapter 2.1.5.2 --- Reagents for Gel Electrophoresis --- p.31 / Chapter 2.1.6 --- Reagents for Western Blotting --- p.32 / Chapter 2.1.6.1 --- Reagents for Protein Extraction --- p.32 / Chapter 2.1.6.2 --- Reagents for SDS-PAGE --- p.33 / Chapter 2.1.7 --- Reagents for Flow Cytometry --- p.36 / Chapter 2.1.8 --- In Vivo Study --- p.37 / Chapter 2.2 --- Methods --- p.38 / Chapter 2.2.1 --- Cell Treatment --- p.38 / Chapter 2.2.2 --- Trypan Blue Exclusion Assay --- p.38 / Chapter 2.2.3 --- MTT Assay --- p.38 / Chapter 2.2.4 --- Detection of DNA Fragmentation --- p.39 / Chapter 2.2.5 --- Flow Cytometry --- p.40 / Chapter 2.2.5.1 --- Detection of Cell Cycle Pattern with PI --- p.40 / Chapter 2.2.5.2 --- Detection of Apoptosis with Annexin V-PI --- p.40 / Chapter 2.2.6 --- Western Blot Analysis --- p.41 / Chapter 2.2.6.1 --- Protein Extraction --- p.41 / Chapter 2.2.6.2 --- Protein Concentration Determination --- p.41 / Chapter 2.2.6.3 --- Western Blotting --- p.42 / Chapter 2.2.7 --- In Vivo Study --- p.44 / Chapter 2.2.7.1 --- Animal Model --- p.44 / Chapter 2.2.7.2 --- Treatment Schedule --- p.44 / Chapter 2.2.7.3 --- Toxicity of Arsenic Trioxide --- p.45 / Chapter Chapter 3 --- Anti-Proliferation Effect of As2O3 on MDA-MB-231 cells --- p.47 / Chapter 3.1 --- Study the Anti-proliferation Effect of As2O3 on MDA-MB-231 Cells by MTT Assay --- p.48 / Chapter 3.2 --- Comparsion Anti-proliferation Effect of AS2O3 on MDA-MB-231 Cells to that of Tamoxifen --- p.50 / Chapter 3.3 --- "Study Toxicity of AS2O3 on Normal Breast Cells Line, 184B5" --- p.52 / Chapter 3.4 --- Summary --- p.54 / Chapter Chapter 4 --- Mechanism of Growth Inhibition Effect of As2O3 on MDA-MB-231 cells --- p.56 / Chapter 4.1 --- Cell Cycle Analysis of As2O3 Treated MDA-MB-231 Cells --- p.57 / Chapter 4.2 --- Detection of DNA Fragmentation --- p.60 / Chapter 4.3 --- Detection of Apoptosis Induced by AS2O3 on MDA-MB-231 Cells by Flow Cytometry --- p.62 / Chapter 4.4 --- Regulation of Apoptotic Related Protein by As2O3 on MDA-MB-231 Cells --- p.64 / Chapter 4.4.1 --- Expression Level of Bcl-2 and Bax Protein --- p.66 / Chapter 4.4.2 --- Expression Level of Cytochrome C --- p.69 / Chapter 4.4.3 --- Expression Level of Caspase9 --- p.71 / Chapter 4.4.4 --- Expression Level of FasL --- p.73 / Chapter 4.4.5 --- Expression Level of Caspase8 --- p.75 / Chapter 4.4.6 --- Expression Level of Caspase3 --- p.77 / Chapter 4.4.7 --- Expression Level of Poly (ADP-ribose) Polymerase (PARP) --- p.79 / Chapter 4.4.8 --- Expression Level of p53 --- p.81 / Chapter 4.5 --- Regulation of Cell Cycle Related Protein by AS2O3 on MDA-MB-231 Cells --- p.83 / Chapter 4.5.1 --- Expression Level of Cyclin B --- p.84 / Chapter 4.5.2 --- Expression Level of Cyclin E --- p.86 / Chapter 4.6 --- Summary --- p.88 / Chapter Chapter 5 --- In Vivo Study of Anti-tumor Effect of As2O3 --- p.89 / Chapter 5.1 --- Anti-tumor Effect of AS2O3 on Tumor Bearing Nude Mice --- p.90 / Chapter 5.2 --- Toxic Effect of AS2O3 on Normal Tissues --- p.93 / Chapter 5.3 --- Summary --- p.98 / Chapter Chapter 6 --- Discussion --- p.99 / Chapter 6.1 --- Anti-tumor Effect of AS2O3 on Breast Cancer --- p.100 / Chapter 6.2 --- Induction of Apoptosis and Cell Cycle arrest by AS2O3 --- p.101 / Chapter 6.3 --- Side Effect of AS2O3 on Breast Cancer Treatment --- p.103 / Chapter Chapter 7 --- Future Perspectives --- p.105 / Chapter 7.1 --- Future Perspectives --- p.106 / References --- p.108