Acute myeloid leukemia (AML) often remains refractory to current chemotherapy and transplantation approaches despite many advances in our understanding of mechanisms in leukemogenesis. The bone marrow “niche” or microenvironment, however, may be permissive to leukemia development and studying interactions between the microenvironment and leukemia cells may provide new insight for therapeutic advances. Mesenchymal stem cells (MSCs) are central to the development and maintenance of the bone marrow niche and have been shown to have important functional alterations derived from patients with different hematological disorders. The extent to which MSCs derived from AML patients are altered remains unclear. The aim of this study was to detect changes occurring in MSCs obtained from human bone marrow in patients with AML by comparing their function and gene expression pattern with normal age-matched controls. MSCs expanded from patients diagnosed with acute leukemia were observed to have heterogeneous morphological characteristics compared to the healthy controls. Immunohistochemistry and flow data confirmed the typical cell surface immunophenotype of CD90+ CD105+ CD73+ CD34- CD45-, although MSCs from two patients with AML revealed reduced surface expression of CD105 and CD90 antigens respectively. Differentiation assays demonstrated the potential of MSCs from AML patients and healthy donors to differentiate into bone, fat and cartilage. However, the ability of MSCs from AML samples to support hematopoietic function of CD34+ progenitors was found to be impaired while the key hematopoietic genes were found to be differentially expressed on AML-MSCs compared to nMSCs. These studies indicate that there exist differences in the biologic profile of MSCs from AML patients compared to MSCs derived from healthy donors. The results described in the thesis provide a formulation for additional studies that may allow us to identify new targets for improved treatment of AML.

Detrimental immune and inflammatory responses contribute to the pathogenesis of various conditions, including Crohn’s disease, Lupus, and sepsis.1,2,3 Unfortunately, novel treatments for detrimental immune and inflammatory responses have been met with little success. Mesenchymal stromal cells (MSCs) represent a promising cellular therapy to treat immune and inflammatory disorders due to their ability to suppress the immune system. However, despite their promise, clinical trials that have employed MSC cellular therapies have produced varying and sometimes conflicting results. These discrepancies have been partially attributed to the cellular heterogeneity within MSC populations. To address these discrepancies, I performed transcriptomic and proteomic analysis of MSCs with varying immunomodulatory capacity to identify robust immunomodulatory biomarkers and gain better mechanistic insights into MSC immunomodulatory function. In this study, MSCs with differing immunomodulatory function were identified and the effect of in vitro passaging and proinflammatory induction on immunomodulatory ability was characterized. To characterize MSC immunomodulatory control mechanisms, RNA sequencing and proteomic analyses were performed on MSCs with different immunomodulatory capabilities. These analyses enabled the identification of potential immunomodulatory biomarkers and regulatory mechanisms. Finally, to test the therapeutic efficacy of immunomodulatory MSC subpopulations, I developed a humanize mouse model for sepsis. Overall, this work contributes to our understanding of MSC immunomodulation and to the development of a robust MSC cellular therapeutics.

Falls among the elderly are a major source of injury, often leading to serious fractures, hospitalization, and death. Osteoporosis (OP) is a global problem intimately related with these fractures, characterized by reduced bone mass, increased bone fragility. There exists a high failure rate in the translation of treatments to osteoporotic populations. Mesenchymal stromal cell (MSC) transplantation as a therapeutic strategy for OP has not yet been examined in clinical trials. This may be attributed to the mixed findings of pre-clinical studies aimed at determining the efficacy of MSC therapy towards bone regeneration in OP. The most common animal model of OP is ovariectomy (OVX) that simulates post-menopausal estrogen loss. A plethora of bone regeneration studies have used OVX models with 12-16 weeks post-OVX periods and have generally reported positive results from a variety of treatment modalities, including MSC therapy. However, the use of the minimum post-OVX period may not be appropriate to reflect the global changes in regenerative potential of OP patients. In our research group's previous study, MSC were isolated from a minimum 60 week post-OVX rat model, representing a severe case of OP. The MSC isolated from these animals are a unique cell population that we expect may better represent the outcomes of autologous cell therapies for the older patient population in the clinic. In the present study, adipose and bone marrow derived MSC from OVX and age-matched animals were evaluated for their osteogenic and adipogenic differentiation potentials in culture through passage 10. Results from this study suggest that bone marrow derived-MSC maintain their phenotype and functionality more effectively than adipose derived-MSC in OP. Further investigations used regenerative medicine approaches for cell expansion on keratin protein coated microcarriers in static culture. Hair-derived keratin biomaterials have demonstrated their utility as carriers of biologics and drugs for tissue engineering. An optimal microcarrier was selected that demonstrated superior retention of the protein coating through electrostatic interactions and high cell viability. Finally, the integration of cell-microcarriers into a perfusion bioreactor system was explored. Preliminary results demonstrated the feasibility of MSC growth and differentiation on microcarrier based packed beds. Moreover, AD-MSC from OP rats were unresponsive to both inductive media and shear stress related osteogenic cues. These results highlight the complexity and challenges associated with the MSC regenerative strategy. / Doctor of Philosophy / Osteoporosis is a skeletal disease that results in reduced bone mass, increased bone fragility and fracture risk. Osteoporotic patients who experience falls suffer serious fractures, hospitalization, and poor bone healing. Several different therapies have been developed for the treatment of osteoporosis, though many are unable to translate from the bench to the clinical population. A popular treatment being investigated is the application of mesenchymal stromal cells (MSC) for fracture repair and the reversal of osteoporotic bone losses. However, cells isolated from aged and osteoporotic patients have been shown to have deficient bone forming properties. Nevertheless, animal models of osteoporosis applying this treatment report amelioration of bone loss. This work seeks to examine a more clinically relevant rat model of osteoporosis. Typical osteoporosis models use an ovariectomy procedure to simulate post-menopausal bone loss on relatively young animals and conduct short-term studies. These studies may not accurately reflect the global regenerative changes in osteoporosis patients or the impaired MSC properties. Adipose and bone marrow derived MSC from a long term ovariectomy model were investigated for their regenerative potentials. MSC growth and bone forming potential was evaluated on keratin protein coated microcarriers in both static and perfusion cultures. Results from this study suggest that bone marrow derived MSC maintain their phenotype and functionality more effectively than adipose derived MSC in osteoporosis. Further preliminary results demonstrated the feasibility of MSC growth and differentiation on microcarrier based packed beds. These results highlight the complexity and challenges associated with the MSC regenerative strategy.

Le cancer du sein est le cancer le plus fréquent chez la femme et représente un problème de santé publique majeur. L'agressivité des tumeurs mammaires varie notamment en fonction de leurstatut pour le récepteur α des oestrogènes (ERα). Les cancers du sein n'exprimant pas ERα ont unmauvais pronostic, de part leur capacité métastatique plus importante. Cependant, les facteurs sous jacents à cette plus grande agressivité des cancers ERα-négatifs restent mal compris. Il est aujourd'hui admis que la progression tumorale et la dissémination métastatique dépendent, non seulement des propriétés intrinsèques des cellules cancéreuses, mais également des régulations exercées sur ces cellules par le micro environnement tumoral. Les interactions entre les cellules cancéreuses et les cellules présentes au niveau du site tumoral, telles que les cellules leucocytaires,les cellules endothéliales, ainsi que les cellules stromales, sont nécessaires au développement et à l'évolution de la tumeur. Ces interactions sont médiées via la production d'hormones, de cytokines ainsi que de chimiokines. Les cellules stromales mésenchymateuses (MSC) sont de composants essentiels du stroma tumoral. Leur rôle dans la progression des tumeurs reste, pour le moment, très controversé. L'objectif de notre projet a été de comprendre les raisons pour lesquelles les MSC peuvent favoriser ou inhiber le développement tumoral. Nous nous sommes, dans un premier temps,intéressés aux interactions entre les cellules cancéreuses mammaires et les MSC. Nous avons déterminé si le fait que les cellules cancéreuses soit métastatiques ou non modifiait le phénotype des MSC et leur réponse dans les régulations de la croissance tumorale. Nous avons ainsi constaté quel es facteurs sécrétés spécifiquement par les cellules cancéreuses métastatiques ERα-négativesinduisaient la production de certaines chimiokines, dont CXCL5. Ces chimiokines peuvent êtressécrétées par les cellules du microenvironnement mais également par les cellules cancéreuses ellesmêmes.Nous avons donc étudié le rôle de CXCL5 dans l'agressivité des tumeurs mammaires. Nousavons ainsi montré que ces chimiokines induisent, in vitro, une augmentation des propriétésprolifératives, invasives et migratoires des cellules cancéreuses. Cette étude nous à permis demontrer que les chimiokines et les interactions entre les cellules cancéreuses et les MSC pouvaientêtre impliquées dans la progression tumorale ainsi que dans l'agressivité des tumeurs mammaires. / Breast cancer remains in Europe and USA the first cause of death by cancer for women.Breast cancer aggressiveness relies in particular on estrogen receptor α (ERa) status. Breast cancers which do not express ERα are more metastatic and have a poorer prognosis, than ERα-positivetumors. However underlying factors involved in these invasive properties are poorly understood.Today, it is established that tumor progression is regulated by intrinsic cancer cells properties, and byinteractions between cancer cells and surrounding microenvironment. Several evidences suggest thatleukocytes, endothelial cells, fibroblasts and infiltrating cells present in stromal compartment caninteract with tumor cells through the production of hormones, cytokines and chemokines.Mesenchymal stromal cells (MSC) belong also to the stromal compartment. Recent studies havehighlighted their potential role in cancer growth and metastasis. However, the ability of MSC to favor orprevent cancer progression remains controversial. The aim of this work was to understand the roles ofMSC in tumor progression and to explain the differential effects of MSC on cancer cells, depending onthe type of cancer cells involved. First, we were analyzed MSC and cancer cells interactions, anddetermined if metastatic cancer cells could affect MSC phenotypes and its response in terms of tumorgrowth. We observed that metastatic breast cancer cells secreted factors, which could highly enhancethe release by MSC of several chemokines, including CXCL5. CXCL5 can be secreted by stromal cellsbut also by cancer cells themselves. We next showed in vitro that CXCL5 increased proliferative,invasive and migratory properties of breast cancer cells. This study allowed us to demonstrate thatchemokines play a role in the cross-talk between MSC and breast cancer cells, and that they play akey role in tumor proliferation and aggressiveness.

Células multipotentes mesenquimais estromais (CTM) são células adultas multipotentes que podem ser isoladas a partir de diferentes tecidos e são capazes de atingir sítios danificados, exercer papéis na regeneração tecidual e modular a resposta imune. Estas células demonstraram resultados discrepantes em estudos in vivo dependentes de sua fonte de obtenção. Há na literatura hipóteses de que o mecanismo predominante pelo qual as CTMs atuam no reparo tecidual estaria relacionado à sua atividade parácrina, criando um microambiente com sinais tróficos. Nesse sentido, a avaliação do conteúdo do secretoma destas células é de grande interesse. Portanto, este projeto teve como objetivo analisar o meio condicionado de CTMs obtidas de diferentes fontes (tecido adiposo, músculo esquelético e tubas uterinas) de mesmos indivíduos. A abordagem experimental consistiu em proteômica shotgun (nanocromatografia líquida acoplada a espectrometria de massas em tandem) com o intuito de identificar alvos diferentemente expressos entre as culturas que possam sugerir funções específicas de cada linhagem celular. Os dados espectrais foram obtidos pelo modo de aquisição dependente de dados (Top15). Os dados adquiridos foram processados pelas plataformas MaxQuant e TPP (Trans-Proteomic Pipeline). Foi realizada análise qualitativa de vias enriquecidas por meio do programa Ingenuity utilizando as proteínas em comum nos secretoma de todas as CTMs analisadas. Essa análise permitiu observar vias enriquecidas de proliferação celular, migração celular e desenvolvimento do sistema cardiovascular, demonstrando que as proteínas secretadas por quaisquer das CTMs analisadas podem ser relacionadas a resultados encontrados na literatura utilizando estas células para terapias para patologias. As análises estatísticas para determinar se haveria dependência da composição do secretoma em função do indivíduo doador ou tecido fonte das CTMs revelaram proteínas diferencialmente expressas entre todos os grupos. Estas proteínas diferencialmente expressas são relacionadas à proliferação, sinalização e interação celular, além de modulação do sistema imune e da angiogênese. Neste contexto, podemos concluir que o secretoma das CTMs é muito semelhante, que as CTMs isoladas de quaisquer tecidos ou indivíduos são capazes de secretar moléculas que possivelmente exercem benefícios em determinado tratamento. Entretanto, estes benefícios podem ser exacerbados ou suprimidos pelas moléculas diferencialmente expressas, as quais são dependentes tanto dos tecidos quanto dos indivíduos dos quais as CTMs foram obtidas / Multipotent Mesenchymal Stromal Cells (MSCs) are multipotent adult cells that can be isolated from different tissues and are able to reach damaged sites, play a role in tissue regeneration and modulate immune response. These cells showed conflicting results in studies in vivo depending on their tissue origin. It is hypothesised that the predominant mechanism by which MSCs function could be related to its paracrine activity, creating a microenvironment with trophic signals. Accordingly, the evaluation of the content of the secretome of these cells is of great interest. Towards this end, this project analyzed the proteins of conditioned medium of MSCs obtained from different sources from the same donors (adipose tissue, uterine tubes and skeletal muscle). The MSCs were characterized by flow cytometry for the presence of membrane markers and by differentiation in vitro into adipocytes, chondrocytes, and osteoblasts. The conditioned media were obtained and the protein profile was analysed by liquid nanochromatography coupled to tandem mass spectrometry. Spectral data were obtained by full-acquisition mode MS / dd-MS2 (Top15). The acquired data were processed by MaxQuant software and TPP (Trans-Proteomic Pipeline). Qualitative analysis of enriched pathways through the Ingenuity program using the shared proteins between the cell lineages was performed.It showed enriched pathways related to cell proliferation, cell migration and development of the cardiovascular system. This allows considering that the secreted proteins from the analyzed MSCs might be related to findings in the literature using these cells for therapies. After this, the proteins were analyzed for differential expression by comparing the MSCs into groups of different sources or different donors. In which were observed differentially expressed proteins related to proliferation, cell signaling and interaction, modulation of the immune system and angiogenesis. In this context, we can conclude that MSC\'s secretome is very similar in the analyzed lineages, and that any MSCs are able to secrete molecules which potentially exert for certain treatment benefits. However, these benefits can be exacerbated or annulled by differentially expressed molecules, which are dependent both as the individual and tissues from which MSCs were obtained

A Esclerose Lateral Amiotrófica (ELA), também conhecida como Doença de Lou Gehrig, é a forma mais comum de doença do neurônio motor. Tem início geralmente tardio (4ª/5ª década de vida), afetando tanto os neurônios motores superiores quanto os inferiores. A degeneração provocada pela ELA é progressiva e irreversível. Em geral, a evolução da doença é rápida, levando os pacientes ao óbito entre 3 e 5 anos após o início dos sintomas, devido principalmente à falência respiratória. Atualmente, o único medicamento liberado pelo FDA (Food and Drug Administration) para o uso em ELA é o Riluzol, que tem um efeito mínimo na expectativa de vida dos pacientes. Neste cenário, a terapia celular vem sendo avaliada como uma possível alternativa. Estudos pré-clínicos indicam efeitos benéficos do tratamento de camundongos SOD1 (modelo animal para ELA) com células estromais mesenquimais ou simplesmente células mesenquimais (MSCs), atribuída principalmente à ação de fatores solúveis. Aqui propusemos o uso de pericitos, uma linhagem celular ainda não testada para tratamento pré-clinico em modelo murinho de ELA. Pericitos são células perivasculares que circundam células endoteliais e que desempenham importantes funções celulares como por exemplo participação da formação e manutenção da barreira hematoencefálica, essencial para proteger o sistema nervoso central de danos em doenças neurodegenerativas. Dessa forma, este trabalho pretendeu comparar o potencial terapêutico de células mesenquimais e pericitos obtidos do tecido adiposo humano de um mesmo doador, em camundongos SOD1. Para tal, testes físicos (peso, PaGE, motor score, rotarod) foram aplicados semanalmente e a sobrevida dos animais foi avaliada. Os resultados demonstram que, com exceção dos benefícios observados nos testes do PaGE e do motor score em uma fase mais inicial da doença, o tratamento com MSCs ou pericitos não resulta em efeitos significativos no quadro clínico de camundongos SOD1 do sexo feminino. Para os machos, o tratamento com pericitos se destaca em relação aos tratamentos com MSCs ou HBSS (veículo), resultando em efeitos benéficos na sobrevida e em determinadas funções motoras dos animais, com destaque para os testes do motor score e do rotarod, onde há uma melhora na fase inicial da doença. A análise da expressão gênica no cérebro e na medula de animais em fase final da doença sugere que o tratamento de machos com pericitos é capaz de estimular as defesas antioxidantes do animal. Ainda nestes órgãos, não foram encontrados vestígios das células humanas injetadas, indicando um possível efeito sistêmico das mesmas / Amyotrophic Lateral Sclerosis (ALS), also known as Lou Gehrig\'s disease, is the most common form of motor neuron disease. Most cases are characterized by an adult onset of symptoms, usually in the fourth or fifth decade of life, affecting both upper and lower motor neurons. The degeneration caused by ALS is progressive and irreversible. On average, the survival ranges from 3 to 5 years after onset, mainly due to respiratory failure. Currently, the only Food and Drug Administration (FDA)-approved medication for this disorder is Riluzole, but its effects on survival are minimal. In this scenario, cell therapy is being evaluated as a possible alternative. Preclinical studies indicate beneficial effects of treatment of SOD1 mice (animal model for ALS) with mesenchymal stromal cells or simply mesenchymal cells (MSCs), mainly attributed to the action of soluble factors. Here we propose the use of pericytes, a cell line not yet tested for preclinical treatment in of ALS. Pericytes are perivascular cells surrounding endothelial cells and play important cellular roles such as assistance of formation and maintenance of the blood-brain barrier, which is essential to protect the central nervous system from damage in neurodegenerative diseases. Thus, this study sought to compare the therapeutic potential of mesenchymal cells and pericytes, both obtained from the same human adipose tissue, in SOD1 mice. For this purpose, survival and physical performance (weight, PaGE, motor score and rotarod) were evaluated. Except for the benefits observed in PaGE and the motor score tests in an early stage of the disease, treatment with MSCs and pericytes does not result in significant effects on disease progression of SOD1 female mice. For males, treatment with pericytes stands out compared to treatment with MSCs or HBSS (vehicle), resulting in beneficial effects on survival and in certain physical functions of the animals, particularly for the motor score and rotarod tests, where improvement was observed in the initial stage of the disease. The analysis of gene expression in the brain and spinal cord in end-stage animals suggests that treatment of males with pericytes can stimulate the animals\' antioxidant defense. No traces of injected human cells were observed in brain or spinal cord of mice, indicating a possible systemic effect of the transplant

Introduction: MSCs are multipotent progenitor cells that can differentiate into various cell lineages, such as osteoblasts, chondrocytes and adipocytes. MSCs synthesize abundant secretion factors to extracellular matrix which contain a variety of growth factors, cytokines and microRNAs. Secretion factors could stimulate the regeneration and differentiation of surrounding cells, but their underlying mechanism still remains elusive. We hypothesized that secretion factors from different tissues derived MSCs had potential to promote MSCs differentiation and musculoskeletal tissue regeneration. We also suggested that microRNAs played an essential role in the effects of secretion factors. In present study, we investigated the effects of secretion factors obtained from different tissues derived MSCs (umbilical cord, dental pulp, gingiva and adipose tissue) on multi-differentiation potentials of MSCs, including osteogenesis, chondrogenesis, tenogenesis, neurogenesis and adipogenesis. Moreover, we illustrated the effects of umbilical cord derived MSC (UCMSC) secretion on bone, cartilage and tendon tissue repair. We further revealed that microRNAs may impact the effect of secretion factors on MSCs osteogenic differentiation. / Methods: Human bone marrow MSCs (hBMSCs) were incubated with various differentiation induction media. Secretion factors were used as supplement. Different animal models of tissue repair (bone, cartilage and tendon) were employed for study of the effects of secretion factors on tissue healing. miRNA microarray was performed to find the potential effective miRNAs in secretion factors. Real time qRT-PCR, microCT, mechanical test, immunohistological analysis and various staining methods were employed as outcome measurements. / Results: We found that both UCMSC and dental pulp derived MCS secretion could initiate osteogenic differentiation of hBMSCs without osteogenic induction medium. UCMSC secretion had positive effect on chondrogenic and tenogenic differentiation of MSCs and inhibitory effect on adipogenesis of hBMSCs. Our results showed that UCMSC secretion in HA/TCP scaffolds with hBMSCs promoted ectopic bone formation in nude mice. UCMSC secretion with rat BMSCs in hyaluronic hydrogel significantly enhanced the bone repair of rat calvarial bone critical defect. To reveal the underlying mechanism, secretion factors were analyzed by miRNA microarray. Among the differentially expressed microRNAs, we found miR-1237 could promote osteogenesis while miR-3676 could inhibit osteogenic differentiation of MSCs. / Conclusions: This study indicated that among secretion factors from MSCs form four types tissues, UCMSC secretion could initiate osteogenesis of MSCs and promote bone repair. We also demonstrated that microRNAs from secretion had impact on osteogenic differentiation of MSCs. Our study showed clinical potential of UCMSC secretion in bone regeneration, and more research are needed for optimizing the preparation and delivery of the MSCs secretive factors, as well as to understand their mechanisms of action. / 前言：間充質幹細胞是具有強大分化潛能的始祖細胞。間充質幹細胞可以分化為多種細胞系，例如成骨細胞，軟骨細胞和脂肪細胞。間充質幹細胞合成并釋放大量分泌素到細胞外基質中。這些分泌素包括多種生長因子，細胞因子和微小核糖核酸。分泌素能夠刺激周圍細胞的再生和分化，但是分泌素的作用機理還不是很清楚。我們認為，不同組織來源的間充質幹細胞分泌素有可能會促進間充質幹細胞的多系分化和骨骼肌肉組織的再生，並且微小核糖核酸在分泌素的效應中發揮了重要作用。我們首先研究了臍帶，牙髓，牙齦和脂肪來源的間充質幹細胞分泌素對于間充質幹細胞的分化能力的作用。我們還對臍帶幹細胞分泌素在骨，軟骨和肌腱修復的效果做了進一步的研究。另外，我們還發現分泌素中的微小核糖核酸在間充質幹細胞的成骨分化方面有一定的效果。 / 方法：我們用人間充質幹細胞來進行誘導分化實驗。臍帶，牙髓，牙齦和脂肪來源的間充質幹細胞的分泌素用於細胞培養基的補充。在體內實驗中我們用了不同的動物模型，把填充物和分泌素一起種植在動物體內。我們利用微小核糖核酸陣列技術來檢測分泌素中的有效微小核糖核酸。我們使用了定量聚合酶鏈反應技術，微型計算機斷層掃描成像，力學測試，免疫組織分析和多種染色方法。 / 結果：我們發現臍帶和牙髓間充質幹細胞分泌素可以在沒有成骨誘導培養基的情況下啟動骨髓間充質幹細胞的成骨分化。臍帶間充質幹細胞對成軟骨和成肌腱分化起到積極作用，而且可以抑制脂肪分化。我們發現在羥基磷灰石/磷酸三鈣材料中，臍帶間充質幹細胞分泌素與人骨髓間充質幹細胞可以共同促進裸鼠的異位成骨。臍帶間充質幹細胞分泌素與鼠骨髓間充質幹細胞一起用於透明質酸水凝膠中能夠加快大鼠頭骨缺損的修復。為了揭示分泌素的作用機理，我們用微小核糖核酸陣列技術來檢測分泌素。在表達不同的微小核糖核酸之中，我們發現miR-1237可以促進間骨髓間充質幹細胞的成骨分化，而miR-3676能夠抑制骨髓間充質幹細胞成骨分化。 / 結論：本研究表明，在四種不同來源的分泌素中，臍帶間充質幹細胞分泌素可以啟動骨髓間充質幹細胞的成骨分化，同時加快骨組織修復。我們發現微小核糖核酸在分泌素的促進間骨髓間充質幹細胞成骨分化的效果中發揮了一定的作用。我們的研究表明，使用臍帶間充質幹細胞分泌素修復骨組織具有廣泛的臨床應用前景。間充質幹細胞分泌素的生產，使用過程和作用機理還有待于進一步的優化和研究。 / Wang, Kuixing. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2014. / Includes bibliographical references (leaves 131-147). / Abstracts also in Chinese. / Title from PDF title page (viewed on 01, November, 2016). / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only.

Dai, Zhuojun. / Thesis Ph.D. Chinese University of Hong Kong 2014. / Includes bibliographical references. / Abstracts also in Chinese. / Title from PDF title page (viewed on 15, September, 2016).

Meng, Fanbiao. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 114-138). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

有證據顯示基質細胞在腫瘤的發生發展中可以發揮重要的作用，基質細胞可以提供適宜腫瘤細胞增殖的腫瘤微環境。腫瘤相關成纖維細胞是一種特殊的與腫瘤生成高度相關的基質細胞。而通过我们的论证，小鼠胚胎成纖維細胞可以作為一種腫瘤相關成纖維細胞的細胞模型。 / 腫瘤誘導因子（TIF）是本實驗室在成瘤實驗中發現的一種新的倉鼠CXC 趨化因子。基于蛋白質序列的分析，TIF 属于Gro CXC 趨化因子家族。這個家族主要通過激活其受體CXCR2 來發揮作用。為了研究TIF 在腫瘤發生中的作用，我們在CHO-K1 細胞中建立了過表達TIF 的穩定細胞株。 / 我們發現共同注射的永生化MEF 與過表達TIF 的D12 細胞導致了腫瘤生長的抑制。為了研究這種現象，重組TIF 蛋白在大腸桿菌中表達，并且用鎳柱進行了提純。純化的蛋白被用于處理CHO-K1 細胞與永生化MEF。我們發現高水平的TIF 可以導致CXCR2 下游的Erk 磷酸化水平下降。其可能的機制為CXCR2 在高水平的TIF 作用下的脫敏作用。同時高水平TIF 可以導致永生化MEF 中CD133 水平的下降。因此，CXCR2 脫敏為TIF 導致腫瘤抑制的可能機制。 / Lines of evidence indicate that stromal cell is one of the determinants in tumor formation by providing a favorable microenvironment for the growth of cancer cells. Cancer associated fibroblast (CAF) is a special form of stromal cells which are shown to be derived from bone marrow. Upon reaching the tumor, the bone marrow-derived mesenchymal stem cells differentiate into CAF, which secrets various growth factors and cytokines to promote cancer growth. Furthermore, genetic study shows that CAF displays p53 mutations and other genetic changes. / Tumor induced factor (TIF) is a CXC chemokine that is originally identified from a xenograft tumor. Sequence analysis suggests TIF is a family member of the Gro CXC chemokines, and exerts its cellular function via activating CXCR2 receptors. In order to investigate the functional roles of TIF, a stable cell line over-expressing TIF in hamster CHO-K1 was established. / To explore the cancer-stromal interactions in xenograft, mouse embryonic fibroblast (MEF) were used as a study model for CAF. MEF was sub-cultured by a conventional protocol that was used for developing the NIH3T3 cells. Based on the growth patterns and expressions of cell markers, growth of MEF can be divided into three stages: the early stage, the senescent stage and the immortalized stage. Our results suggested that MEF might mirror the various developmental stages of CAF. / To examine the contributions of MEF in tumorigenesis, CHO-K1 cells and MEF were co-injected into nude mice. Intriguingly, MEF that in senescent and immortalized stages, rather than in early stage, promoted tumor formation. A possibility arose that the contribution of senescent and immortalized MEF in promoted tumorigenesis may due to CD133 and CXCL1, as the expression of CD133 and CXCL1 in senescent and immortalized MEF were higher than that of MEF in early stage. Moreover, as MEF could gradually develop into a fibroblast promoted tumor formation, MEF could be used as a crucial model to illustrate the origination and development of CAF. / Surprisingly, in nude mice co-injected with immortalized MEF with TIF-overexpressing D12 cells, suppression instead of promotion of tumor growth was found. In order to explore the underlined mechanism of tumor suppression, recombinant TIF protein was purified based on a bacterial expression system. Using purified TIF protein to treat CHO-K1 cells and MEF, it was found that low concentration of TIF promoted Erk phosphorylation but high concentration of TIF suppressed it, which might resulted from desensitization of CXCR2 receptors. Reduction of Erk phosphorylation resulted in decreased proliferation in CHO-K1 cells and alleviated expression of CD133 in MEF, which could be the mechanisms for TIF-induced tumor suppression in nude mice. / Taken together, a CAF model was established to examine the function of TIF in tumor-fibroblast interactions. Mechanistic studies indicated that TIF-induced tumor suppression in nude mice was mediated via desensitization of CXCR2 receptors by high concentration of TIF in the tumor microenvironment. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Qi, Wei. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 189-206). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Chapter Chapter 1 --- General Introduction / Chapter 1.1 --- Tumorigenesis --- p.4 / Chapter 1.1.1 --- Virus transformation --- p.4 / Chapter 1.1.2 --- Proto-oncogene and oncogene --- p.5 / Chapter 1.1.3 --- Tumor suppressor gene --- p.7 / Chapter 1.1.4 --- Epigenetic alteration --- p.9 / Chapter 1.1.5 --- Cancer stem cell --- p.11 / Chapter 1.1.6 --- Tumor microenvironment --- p.14 / Chapter 1.2 --- Cancer associated fibroblast (CAF) --- p.17 / Chapter 1.2.1 --- Markers for CAF --- p.17 / Chapter 1.2.2 --- CAF and normal fibroblast --- p.20 / Chapter 1.2.3 --- CAF, a important player in tumor growth --- p.22 / Chapter 1.2.4 --- CAF and angiogenesis --- p.23 / Chapter 1.2.5 --- CAF and tumor invasion --- p.25 / Chapter 1.3 --- Chemokine --- p.27 / Chapter 1.3.1 --- Structure of chemokine --- p.27 / Chapter 1.3.2 --- Chemokine and cell Recruitment --- p.30 / Chapter 1.3.3 --- Chemokine and tumor microenvironment --- p.30 / Chapter 1.4 --- Tumor Induced Factor and its induced tumor suppression --- p.38 / Chapter 1.5 --- The aims of the project --- p.47 / Chapter Chapter Two --- Purification of Tumor Induced Factor / Chapter 2.1 --- Introduction --- p.49 / Chapter 2.2 --- Materials --- p.52 / Chapter 2.2.1 --- Chemical --- p.52 / Chapter 2.2.2 --- Enzyme --- p.52 / Chapter 2.2.3 --- Antibody --- p.52 / Chapter 2.3 --- Method --- p.53 / Chapter 2.3.1 --- Overview of protein expression system --- p.53 / Chapter 2.3.2 --- Purification of Trx-His₆-S-TIF protein --- p.54 / Chapter 2.3.3 --- BCA assay --- p.60 / Chapter 2.3.4 --- SDS-PAGE --- p.60 / Chapter 2.3.5 --- Western blotting --- p.61 / Chapter 2.3.6 --- Preparation of pET28/His₆-Sumo-TIF bacterial expression vector --- p.62 / Chapter 2.3.7 --- Optimization of culture condition for BL21 expressed His₆-Sumo-TIF protein --- p.67 / Chapter 2.3.8 --- Purification of His₆-Sumo-TIF protein --- p.68 / Chapter 2.3.9 --- Homology model of TIF --- p.68 / Chapter 2.4 --- Results --- p.69 / Chapter 2.4.1 --- Purification of Trx-His₆-S-TIF --- p.70 / Chapter 2.4.2 --- Optimization of purification protocol of His₆-Sumo-TIF --- p.71 / Chapter 2.4.3 --- Large scale purification of mature TIF --- p.75 / Chapter 2.4.4 --- Homology modeling of TIF --- p.80 / Chapter 2.5 --- Discussion --- p.83 / Chapter Chapter 3 --- Three Stages Hypothesis / Chapter 3.1 --- Introduction --- p.86 / Chapter 3.2 --- Material --- p.93 / Chapter 3.2.1 --- Chemical --- p.93 / Chapter 3.2.2 --- Enzyme --- p.93 / Chapter 3.2.3 --- Animal --- p.93 / Chapter 3.2.4 --- Antibody --- p.94 / Chapter 3.3 --- Methods --- p.95 / Chapter 3.3.1 --- Isolate MEF from 13.5 days mouse embryo --- p.95 / Chapter 3.3.2 --- Culture of MEF following 3T3 protocol --- p.96 / Chapter 3.3.3 --- X gal staining --- p.96 / Chapter 3.3.4 --- Analysis of MEF cell size and complexity by flow cytometry --- p.98 / Chapter 3.3.5 --- MTT assay --- p.98 / Chapter 3.3.6 --- Analysis of CD133 by flow cytometry --- p.99 / Chapter 3.3.7 --- ROS detected by DCFH-DA fluorescent probe --- p.99 / Chapter 3.3.8 --- Double staining of cancer stem cell marker and ROS fluorescent probe --- p.100 / Chapter 3.3.9 --- Reverse transcription --- p.101 / Chapter 3.3.10 --- Analysis CXCL1 mRNA expression level by PCR --- p.102 / Chapter 3.3.11 --- Gelatin zymography --- p.103 / Chapter 3.3.12 --- In-vivo tumorigenicity assay --- p.104 / Chapter 3.4 --- Results --- p.106 / Chapter 3.4.1 --- Three Stages of MEF --- p.106 / Chapter 3.4.2 --- X gal staining --- p.106 / Chapter 3.4.3 --- Flow cytometric analysis of cell diameter and cellular complexity of MEF --- p.109 / Chapter 3.4.4 --- MTT assay --- p.109 / Chapter 3.4.5 --- CD 133 expression of MEF detected by flow cytometry --- p.110 / Chapter 3.4.6 --- Reactive oxygen species of MEF detected by flow cytometry --- p.118 / Chapter 3.4.7 --- The level of ROS and CD133 of MEF detected by flow cytometry stimultaneously --- p.121 / Chapter 3.4.8 --- TIF treatment reduces the small CSC subpopulation in senescent stage MEF --- p.124 / Chapter 3.4.9 --- Increased CXCL1 expression in senescent stage and immortalized stage MEF --- p.125 / Chapter 3.4.10 --- Matrix metalloproteinase 2 activities in different stages of MEF . --- p.129 / Chapter 3.4.11 --- In vivo tumorigenicity assay --- p.130 / Chapter 3.5 --- Discussion --- p.133 / Chapter Chapter Four --- Biphasic Effect of TIF in Cancer-Fibroblasts Interaction / Chapter 4.1 --- Introduction --- p.140 / Chapter 4.2 --- Material --- p.143 / Chapter 4.2.1 --- Chemical --- p.144 / Chapter 4.2.2 --- Kit and Instrument --- p.144 / Chapter 4.2.3 --- Antibody --- p.144 / Chapter 4.3 --- Method --- p.145 / Chapter 4.3.1 --- Purification of TIF-His₆-Flag --- p.145 / Chapter 4.3.2 --- Western blotting to detect purified TIF-His₆-Flag --- p.145 / Chapter 4.3.3. --- Measurement of cell proliferation by cell counting --- p.145 / Chapter 4.3.4 --- MTT assay --- p.146 / Chapter 4.3.5 --- Western blotting to detect pErk and total Erk --- p.146 / Chapter 4.3.6 --- Soft agar assay --- p.148 / Chapter 4.3.7 --- Gelatinase detection --- p.148 / Chapter 4.3.8 --- Wound healing assay --- p.149 / Chapter 4.3.9 --- Colony formation assay --- p.149 / Chapter 4.3.10 --- Detection of CD133 by flow cytometry --- p.150 / Chapter 4.4 --- Results --- p.151 / Chapter 4.4.1 --- Purification of TIF-His₆-Flag --- p.151 / Chapter 4.4.2 --- Reduced cell proliferation of D12 in long time culture --- p.153 / Chapter 4.4.3 --- Reduced metabolic activities of D12 cells in time culture --- p.155 / Chapter 4.4.4. --- TIF-CXCR2-pErk signal axis in CHO cells --- p.155 / Chapter 4.4.5 --- Bigger colonies formed by D12 cells in soft agar assay --- p.161 / Chapter 4.4.6 --- TIF-CXCR2-pErk-MMP9 signal pathway in D12 cells --- p.162 / Chapter 4.4.7 --- Reduced migration of D12 cells --- p.164 / Chapter 4.4.8 --- Reduced cell invasion of D12 cells --- p.165 / Chapter 4.4.9 --- Reduced colony number of D12 cells in colony formation assay --- p.168 / Chapter 4.4.10 --- Bi-phasic “bell shape“ bi-phasic response on Erk activation of TIF in CHO-K1 cells --- p.169 / Chapter 4.4.11 --- Bi-phasic “bell shape“ effect of TIF to pErk in immortalized MEFs --- p.172 / Chapter 4.4.12 --- Reduced CD133 in immortalized MEF by high concentration of TIF --- p.173 / Chapter 4.5 --- Discussion --- p.177 / Chapter Chapter Five --- General Discussion / Chapter 5.1 --- Project Summary --- p.183 / Chapter 5.2 --- Significances of the project --- p.185 / Chapter 5.3 --- Future work --- p.188