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The stringent requirement for hemopoietic growth factors (HGF) in the induction of hemopoiesis in vitro has raised questions as to their possible role(s) in leukemogenesis. Several recent clinical studies have shown aberrant cell growth factor gene activation in patient derived leukemic cells. Assessment of growth factor activity is often based on in vitro bioactivity assays of conditioned media or body fluids. The specificity of this type of endpoint is, however, open to question due to the overlap in biological activities of many HGFs. In assessing the role of growth factor gene expression in a murine myeloid leukemia model I have used a sensitive RNA detection procedure coupled with a vector-probe system that enables the synthesis of uniformly labelled radioactive DNA probes to detect unambiguously the expression of particular growth factor genes. The Abelson murine leukemia virus (A-MuLV) derived myeloid transformants used in this study had previously been shown to produce a multi-lineage colony stimulating activity (CSA). While these A-MuLV transformants were shown to produce GM-CSF, it seemed likely that the multi-lineage CSA was due to another factor. In addition to confirming the expression of GM-CSF mRNA, I was able to show that the cells of all four A-MuLV transformed lines tested also expressed interleukin-3 mRNA. This finding was strongly corroborated by bio-activity data obtained using the CM from the A-MuLV myeloid transformants. Additional preliminary analysis by bioactivity assays have also shown the possible presence of interleukin-6 (IL-6) and a recently described pre-B cell factor suggesting perhaps a common mechanism underlying the activation of these various growth factor genes. / Medicine, Faculty of / Medical Genetics, Department of / Graduate

N^6,O^2' -Dibutyryl cyclic adenosine 3',5'-monophosphate (Bt_2cAMP) was investigated for its effects on various tissue culture cells infected with temperature-sensitive (ts) mutant, LA31 and Bratislava 77 (B77), a wild-type Rous sarcoma virus. Specifically, known parameters of transformation were investigated and a possible site of action has been tenably proposed. The drug Bt_2cAMP was found to have little effect on the transformation related properties of primary chick embryo fibroblasts (CEF) infected with either virus or normal rat kidney fibroblasts (NRK) infected with the wild-type B77-RSV. However, significant inhibition of the transforming properties in NRK infected with the ts mutant LA31 (LA31-NRK) were reported at the permissive temperature 33 degrees centigrade (33 C).

LA31-NRK and B77-NRK are established cell lines that were normal rat kidney cells transformed with temperature-sensitive mutant (LA31) and wild-type Bratislava 77 (B77) of Rous sarcoma virus. It is recognized that many transformation-induced changes differentiate between normal and transformed cells. Morphology and four parameters of transformed cells such as saturation density, anchorage independence, plasminogen activator, and colony stimulating factor were used as indicators to observe the effect of human alpha interferon on the growth of NRK, LA31-NRK and B77-NRK. The results show that interferon could neither reverse the transformed cells to normal fashion nor change their behaviors or cause release of protease.

Mutações com ganho de função do proto-oncogene Ras se encontram entre umas das mais freqüentes modificações em cânceres humanos, além disso, tumores com esses caracterísitcas possuem, em geral, mau prognóstico. O objetivo inicial desta tese foi estudar novos mecanismos anti-proliferativos disparados por dois agentesmitogênicos, FGF2 (\"Fibroblast Growth Factor 2\") e PMA (\"Phorbol-12-Myristate-13-Acetate\", (um diéster de forbol), sobre células de camundongos transformadas por Ras e refratárias a apoptose. Para isso utilizamos duas linhagens celulares: uma linhagem naturalmente trtansformada por uma ampliação do gene K-Ras, que é derivada de um tumor de córtex adreno-cortical de camundongo e é denominada Y1, e uma sublinhagem derivada de Balb/c-3T3, transformada em laboratório com o oncogene H-RasV12 humano. A fim de se elucidar o mecanismo de ação de FGF2, foram selecionadas e caracterizadas múltiplas sublinhagens clonais resistentes a FGF2, derivadas das linhagens parentais Y1 e B61. Mostramos assim, que o FGF2 exerce um forte efeito negativo, de forma que os clones resistentes ao mesmo tendem a perder aos altos níveis de expressão da proteína Ras. Mostramos ainda que esses células passam a ser dependentes de FGF2 para crescer em cultura, perdem a capacidade de crescimento em suspensão e são menos tumorigênicas quando comparadas às células parentais. Em uma segunda etapa, caracterizamos o efeito citotóxico de PMA sobre células transformadas por Ras, e vimos que esse efeito é mais acentuado para células transformadas por K-Ras, mas é nulo sobre células imortalizadas não tumorigênicas. Mostramos ainda que esse efeito passa pela ativação da via de PKC. A inibição da proliferação por PMA se deve, ao menos parcialmente, à indução de senescência nessas células. De forma semelhante ao que foi para o estudo com FGF2, foram selecionados clones resistentes a PMA, derivados de Y1. Os clones obtidos se mostraram muito instáveis, pouco resistentes a PMA e dependentes de FGF2 para crescer. Todos os clones testados se mostram tumorigênicos, entretanto, apresentaram maior tempo de latência, estaticamente diferente da célula parental, Y1. Assim, neste trabalho, mostramos que duas substâncias, com caráter mitogênico e potencialmente oncogênico, são capazes de inibir seletivamente a proliferação de células transformadas por Ras, uma vez que elas não têm efeito sobre células não transformadas. Desvendar os mecanismos que causam a citotoxidade dessas substâncias deve trazer informações relevantes com possibilidades de impacto em terapia de tumores dependentes dos oncogenes Ras. / Amplification and gain of function mutations in ras proto-oncogenes are frequent genetic lesions in human cancers of bad prognostic. This thesis aimed to investigate novel anti-proliferative mechanisms induced by two mitogens, FGF2 (\"Fibroblast Growth Factor 2\") and PMA (\"Phorbol-12-Myristate-13-Acetate\", a phorbol diester), in murine cell lines transformed by ras and resistant to apoptosis. To this end, we took two different mouse malignant cell lines: Y1, a cell line derived from an adrenal tumor, naturally transformed by K-ras amplification and another one, 3T3-B61, obtained by transformation of Balb-3T3 fibroblasts with the H-rasV12 oncogene. To elucidate FGF2 mechanisms of action, we selected, isolated and characterized clonal sublines resistant to FGF2 from both Y1 and 3T3-B61 parental lines. FGF2-resistant clones are rare normal-like revertant sublines that no longer display Ras over expression, dependent on FGF2 for growth, do not grow in suspension cultures and exhibit low tumorigenicity in Nude mice. These results show that FGF2 exerts a strong selective pressure against ras-transformed cells, inducing senescence and irreversibly blocking proliferation. Differently from FGF2 , PMA citotoxic effect is completely dependent on PKC activity. In addition, PMA is highly toxic to K-Ras transformed Y1 cells, poorly toxic to H-Ras-transformed 3T3-B61 cells and not toxic to immortalized non tumorigenic cell lines. Attempts to select PMA-resistant cells fropm Y1 parental line have yielded very rare, highly clonal sublines, dependent on FGF2 for proliferation. In conclusion, two mitogens, FGF2 and PMA, can selectively inhibit Ras-driven proliferation, a phenomenon of great interest for biology and therapy of tumors dependent on ras oncogenes.

Yuen Mong Ting. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 155-169). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract (English) --- p.ii / Abstract (Chinese) --- p.v / Contents --- p.vi / Chapter Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Developmental biology of the prostate --- p.1 / Chapter 1.1.1 --- Development of the prostate gland in humans and rodents --- p.1 / Chapter 1.1.2 --- Mesenchymal-epithelial interaction --- p.2 / Chapter 1.2 --- Overview of the endocrinology of prostate --- p.3 / Chapter 1.3 --- Estrogen in male and prostate gland --- p.4 / Chapter 1.3.1 --- Stimulating effect of estrogen on prostate gland --- p.4 / Chapter 1.3.2 --- Inhibitory effect of estrogen on prostate gland --- p.5 / Chapter 1.4 --- Study of the role of estrogen receptors in prostate gland with the use of estrogen receptor knockout mice --- p.6 / Chapter 1.4.1 --- The two isoforms of estrogen receptors (ER): ERα and ERβ --- p.6 / Chapter 1.4.2 --- The use of estrogen receptor knockout mice for the study of ER --- p.7 / Chapter 1.5 --- Estrogen as a carcinogen --- p.8 / Chapter 1.5.1 --- Formation of DNA adducts --- p.8 / Chapter 1.5.2 --- Formation of oxidants --- p.9 / Chapter 1.5.3 --- Estrogen as a microtubule-disrupting agent --- p.10 / Chapter 1.6 --- Estrogen carcinogenicity in animal models --- p.11 / Chapter 1.6.1 --- Syrian golden hamster model --- p.11 / Chapter 1.6.2 --- Rat model --- p.12 / Chapter 1.7 --- Animal models of prostate cancer by hormonal induction --- p.12 / Chapter 1.7.1 --- Canine model --- p.13 / Chapter 1.7.2 --- Noble rat model --- p.13 / Chapter 1.7.3 --- Sprague-Dawley rat model --- p.15 / Chapter 1.7.4 --- Wistar and F344 rat model --- p.15 / Chapter 1.8 --- Perinatal estrogen exposure and prostate development --- p.16 / Chapter 1.8.1 --- Prenatal estrogen exposure --- p.15 / Chapter 1.8.2 --- Neonatal estrogen exposure --- p.17 / Chapter 1.9 --- Therapeutic use of synthetic estrogen --- p.18 / Chapter 1.9.1 --- Use of diethylstilbestrol in treating prostate cancer --- p.18 / Chapter 1.9.2 --- Use of diethylstilbestrol during pregnancy --- p.19 / Chapter 1.10 --- Estrogen contamination in food --- p.20 / Chapter 1.10.1 --- Estrogen in milk and dairy products --- p.20 / Chapter 1.10.2 --- Estrogen in meat --- p.21 / Figure 1.1 --- p.23 / Chapter Chapter 2. --- Materials and methods --- p.25 / Chapter 2.1 --- In vitro study of estrogen carcninogenicity in normal prostatic cell line --- p.25 / Chapter 2.1.1 --- NRP-152 cell line --- p.25 / Chapter 2.1.2 --- In vitro estrogen treatment on NRP-152 cells --- p.25 / Chapter 2.1.3 --- Colony formation by soft agar assay --- p.27 / Chapter 2.1.4 --- Determination of growth parameters of estrogen-treated and untreated NRP-152 cells --- p.29 / Chapter 2.1.5 --- Gene expression profiling in estrogen-transformed and untreated parental NRP-152 cells by cDNA microarray --- p.30 / Chapter 2.1.6 --- Immunohistochemistry of cultured cells --- p.34 / Chapter 2.1.7 --- Immunofluorescence on cultured cells --- p.36 / Chapter 2.1.8 --- Electron microscopy of the estrogen-transformed and untreated parental NRP-152 cells --- p.37 / Chapter 2.1.9 --- Tumorigenicity in nude mice --- p.38 / Chapter 2.1.10 --- Protein expressions and Western blottings in estrogen-transformed and untreated parental NRP-152 cells --- p.39 / Chapter 2.2 --- In vivo study of estrorgen carcinogenicity in rat protstate gland --- p.41 / Chapter 2.2.1 --- Origin and supply of Noble rats --- p.41 / Chapter 2.2.2 --- Perinatal estrogen imprinting on male Noble rats with diethylstilbestrol --- p.42 / Chapter 2.2.3 --- Long-term hormonal treatment with sex steroids on male Noble rats at adulthood --- p.43 / Chapter 2.2.4 --- Morphological study of Noble rat prostates --- p.44 / Chapter 2.2.5 --- Protein expressions by immunohistochemistry in estrogen-primed and hormone-treated Noble rat prostates --- p.45 / Tables 2.1 -2.2 --- p.48 / Chapter Chapter 3. --- Results --- p.50 / Chapter 3.1 --- In vitro study --- p.50 / Chapter 3.1.1 --- Dose selection for estrogen treatment of NRP-152 cells from cell proliferation assay --- p.50 / Chapter 3.1.2 --- Colony formation in soft agar --- p.50 / Chapter 3.1.3 --- Morphology of NRP-152 cells and the estrogen-transformed clones --- p.51 / Chapter 3.1.4 --- Study of growth parameters --- p.52 / Chapter 3.1.5 --- CDNA array analysis of differentia] gene pattern --- p.53 / Chapter 3.1.6 --- Immunohistochemistry of untreated parental and estrogen- transformed NRP-152 cells --- p.55 / Chapter 3.1.7 --- Electron microscopy --- p.58 / Chapter 3.1.8 --- Tumorigenicity of NRP-152 cells and the estrogen-transformed clones --- p.59 / Chapter 3.1.9 --- Western blottings --- p.59 / Chapter 3.2 --- In vivo study --- p.52 / Chapter 3.2.1 --- Survival of male Nobel rats during perinatal and long-term hormone treatment --- p.62 / Chapter 3.2.2 --- Histological studies of Noble rat prostates --- p.63 / Chapter 3.2.3 --- Immunohistochemistry of the hormone-treated and control Noble rat prostates --- p.65 / Figure 3.1.1 -3.1.44 --- p.73 / Figure 3.2.1 - 3.2.50 --- p.97 / Table 3.1 -3.4 --- p.117 / Chapter Chapter 4. --- Discussions --- p.121 / Chapter 4.1 --- The study on the transformation of cells and soft agar assay --- p.121 / Chapter 4.2 --- Growth patterns of the estrogen-transformed clones --- p.123 / Chapter 4.3 --- Altered differential gene expression --- p.124 / Chapter 4.3.1 --- TUBA --- p.124 / Chapter 4.3.2 --- PTEN --- p.125 / Chapter 4.3.3 --- RAP 1A --- p.126 / Chapter 4.3.4 --- BRCA2 --- p.126 / Chapter 4.4 --- Ultrastructural study in the estrogen-transformed and untreated parental NRP-152 cells --- p.127 / Chapter 4.5 --- Neoplastic lesions induced in prostates of estrogen-imprinted and long-term combined hormone treated Noble rats --- p.129 / Chapter 4.6 --- Altered protein expressions in estrogen-transformed NRP-152 cells and estrogen-imprinted and hormone-treated Noble rat prostates --- p.132 / Chapter 4.6.1 --- Alteration in steroid hormone receptors --- p.132 / Chapter 4.6.2 --- Alternation in cytoskeleton (tubulin-α) --- p.138 / Chapter 4.6.3 --- Alternation in PTEN --- p.141 / Chapter 4.6.4 --- Alternation in Rap1 --- p.143 / Chapter 4.6.5 --- Alternation in BRCA2 --- p.145 / Chapter 4.6.6 --- "Altered in scavenger enzyme (Superoxide dismutase, SOD-1)" --- p.147 / Chapter Chapter 5. --- Summary --- p.150 / Reference --- p.155

1. Transfection is a key technique in cell and molecular biology with many important biochemical applications. We selected a fiber fs laser at 1554 nm, an instrument widely used in optical communication research, as the excitation source. Our results demonstrated that the fs laser could perforate the cell membrane and the hole would close in sub-second interval after the laser exposure. We determined the safe exposure duration by detecting if there was any sign of mitochondrial depolarization at 1.5 hours after photoporation. Furthermore, we had successfully transfected HepG2 cells with a plasmid DNA containing the OFP gene, whose fluorescence could still be detected 24 hours after exposure. The transfection efficiency was as high as 77.3%. We also observed the proliferation of the transfected cells after 48 hours. / 2. Cell-cell fusion is a powerful tool for the analysis of gene expression, chromosomal mapping, monoclonal antibody production, and cancer immunotherapy. One of the challenges of in vitro cell fusion is to improve the fusion efficiency without adding extra chemicals while maintaining the cells alive and healthy. We show here that targeted human cancer cells could be selected by an optical tweezer and fused by a finely focused fs laser beam at 1554 nm with a high fusion eftlciency. The result confirmed that human cells could be fused exclusively by fs laser pulses, and this is the first time human cells are fused together all-optically. Mixing of cytoplasm in the fused cells was subsequently observed, and cells from different cell lines were also fused. Based on these, we firstly developed the method of optical cell-cell fusion. / 3. Failure in the induction of apoptosis or programmed cell death is one of the major contributions to the development of cancer and autoimmune diseases. Here we used a fs laser as a novel method to provide a direct apoptosis trigger to observe dynamic changes at subcellular level during apoptosis. First, we examined the effect of fs laser irradiation on the creation of reactive oxygen species (ROS) in exposed cells, which could trigger programmed cell death. By controlling the mitochondria electron transport chain (ETC), we investigated the mechanism of ROS generation by the fs pulses, including thermal effect and direct free electron liberation. Second, we induced apoptosis to targeted cells by the fs laser and found that the nuclear envelope (NE) formed tubular or tunnel-like structures (nuclear tubules - NT) inside the nucleus. The average number of NTs in each cell with laser treatment was significantly larger than in the control. Besides, the development of a NT was observed since its inception and it eventually merged with another one to form a larger NT. Meanwhile, mitochondria and tubulin were found inside the NT, and the NT formation always occurred after an upsurge of cellular Ca2+ concentration. More DNA fragmentation were also found in the region around the NTs. Based on this, we propose that NTs are developed during apoptosis and mitochondria migrate into the nucleus through the NTs to release death signals to trigger DNA fragmentation. Third, we used the fs laser to induce Ca2+ in cells in the form of a slow release, and firstly discovered that most Ca2+ was stored in the cytoplasm, and could diffuse into the nucleus after the optical trigger. Using fast confocal scanning, we obtained the path way of Ca2+ diffusion after the trigger in different cases. Our findings thus provide a new method of regulating the rate of apoptosis. / Biophotonics is an exciting and fast-expanding frontier which involves a fusion of advanced photonics and biology. It has not only developed many novel methodologies for biomedical research, but also achieved significant results as an independent field. Aided with femtosecond (fs) laser technologies, important progresses have been made on manipulating, imaging, and engineering of biological samples from single molecules to tissues in the last 10 years. The laser beam of ultra-short pulses at near-infrared band enjoys a lot of advantages: high nonlinear efficiency, low absorption by biological samples, high spatial and temporal resolution with tight confinement, low photo-toxicity, non-invasive, and ease of control. In this thesis, we report new findings from cell manipulation by fs laser, including transfection, cell-cell fusion, and induction of apoptosis in cells, which are detailed as follows: / He, Hao. / Adviser: Kam Tai Chan. / Source: Dissertation Abstracts International, Volume: 73-03, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

by Yang Lei. / Publication date from spine. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 110-126). / Acknowledgement --- p.i / Abstract --- p.ii / Abbreviations --- p.v / Table of Contents --- p.vi / Chapter Chapter 1 --- Introduction --- p.1 / Chapter Chapter 2 --- Literature Review --- p.4 / Chapter Chapter 3 --- Materials and Methods --- p.41 / Chapter Chapter 4 --- Results --- p.58 / Chapter Chapter 5 --- Discussion --- p.86 / References --- p.110 / Appendix --- p.120 / Publications --- p.125 / Illustrations --- p.127