Metastasis is the primary cause of mortality in women with breast cancer. Recently, elevated serum levels of a glycoprotein known as chitinase-3 likeprotein- 1 (CHI3L1) has been correlated with poor prognosis and shorter survival of patients with cancer and inflammatory diseases. The biological and physiological functions of CHI3L1 in tumor progression have not yet been elucidated. In this document, we describe the role of CHI3L1 in tumor growth and metastasis and its relationship with inflammation. Using well-established models of breast cancer, we show that CHI3L1 is increased in the serum of tumor bearing mice. We found that CHI3L1 levels are increased at both the “pre-metastatic” and “metastatic stage” and that tumor cells, splenic, alveolar and interstitial macrophages; and myeloid derived population produce CHI3L1. Furthermore, we demonstrated that CHI3L1 has an inhibitory role on the expression of interferon-gamma (IFN γ) by T cells, while enhancing the production of pro-inflammatory mediators by macrophages such as Cchemokine ligand 2 (CCL2/MCP-1), Chemokine CX motif ligand 2 (CXCL2/IL-8) and matrix metalloproteinase-9 (MMP-9), all of which promote tumor growth and metastasis. We demonstrated that in vivo treatment of tumor-bearing mice with chitin microparticles, a TH1 adjuvant and a substrate for CHI3L1, promoted immune effector functions with increased production of IFN-γ but decreased CCL2/MCP-1, CXCL2/IL-8 and MMP-9 expression by splenic and pulmonary macrophages. Significantly, in vivo administration of chitin microparticles decreased tumor growth and pulmonary metastasis in mammary tumor bearing mice. These results suggest that CHI3L1 may play a role in tumor progression. Inflammation plays a pivotal role during tumor progression and metastasis by promoting the production of pro-inflammatory molecules such as CHI3L1. However, little is known about how CHI3L1 expression can affect secondary sites to enhance metastasis. In these studies, we demonstrated that CHI3L1 alters the cellular composition and inflammatory mediators that aid in the establishment of a metastatic niche for the support of infiltrating tumor cells leading to accelerated tumor progression. Since previous studies showed that CHI3L1 modulates inflammation, we determined the role of CHI3L1 in the context of pre-existing inflammation and metastasis. We found that CHI3L1 deficient mice with preexisting inflammation had decreased pro-inflammatory mediators, and significant reduction in tumor volume and metastasis compared to wild type controls. Preexisting inflammation and CHI3L1 may be driving the establishment of a premetastatic milieu in the lungs and aiding in the establishment of metastasis. Understanding the role of CHI3L1 in inflammation during tumor progression could result in the design of targeted therapies for breast cancer patients. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2015. / FAU Electronic Theses and Dissertations Collection

A fração plasmática da lipoproteína de baixa densidade (LDL) é formada por partículas de diferentes tamanhos, carga e densidade. Baseada na diferença de carga das partículas, a LDL pode ser subfracionada em LDL nativa (nLDL) e LDL eletronegativa (LDL‾). A LDL‾ está presente no plasma e possui propriedades aterogênicas e pró-inflamatórias, assim como, possui menor concentração de antioxidantes lipossolúveis, maior concentração de dienos conjugados, alterações conformacionais da apoliproteína B-100 e menor afinidade para o receptor da LDL em comparação com a nLDL. Concentrações elevadas de LDL‾ têm sido observadas em pacientes com alto risco para o desenvolvimento de doenças cardiovasculares, incluindo hipercolesterolemia familiar, diabetes. Considerando-se que os mecanismos envolvidos na formação endógena da LDL‾ ainda não estão elucidados, neste estudo foi investigado o efeito da glicoxidação e da lipólise sobre a partícula LDL para avaliar a contribuição destes processos para a formação da LDL‾ in vitro e in vivo. As modificações químicas da LDL e da imunorreatividade com anticorpo monoclonal anti-LDL‾ foi analisada antes e depois da incubação do plasma com lipoproteína lipase (LPL) ou fosfolipase A2 (PLA2), assim como mimetizando-se a lipólise intravascular. Além disso, na lipólise in vivo foi monitorado no periodo pós-prandial em indivíduos normolipidêmicos para investigar a LDL‾ formada endogenamente. A contribuição da glicoxidação para a geração de LDL‾ foi avaliada in vitro pela incubação da LDL com glicose. O efeito da glicoxidação endógena foi monitorada pela medida, ex-vivo, dos os produtos de glicação avançada (AGEs) e LDL‾ no plasma de pacientes diabéticos tipo I (DM I), tipo II (DM II) e indivíduos intolerantes à glicose (IGT). O processo de glicação não enzimática, in vitro, resultou no aumento da concentração de LDL‾. Os indivíduos dos grupos DM I, DM II e IGT apresentaram concentrações plasmáticas elevadas de LDL‾ em relação aos seus respectivos controles, enquanto observou-se aumento de AGEs apenas nos grupos DM I e DM II. O processo de lipólise in vitro mediado pela LPL e PLA2, induziu aumento significante da concentração de LDL‾; entretanto, somente pela ação da LPL foi associada com modificações oxidativas. Em concordância, o processo de lipólise in vivo (pós-prandial) também promoveu aumento significativo da concentração de LDL‾ associado com modificações oxidativas. Conclusão, nossos dados mostram que, glicoxidação e de lipólise, poderiam contribuir na formação da LDL‾ in vivo. / The low density lipoprotein (LDL) fraction in blood plasma is formed by particles with different size, charge and density. Based on particle charge differences, LDL fraction may be separated into native (nLDL) and electronegative (LDL‾) subfractions. LDL‾ is present in blood plasma and has atherogenic and proinflammatory properties, as well as, lower concentrations of lipid soluble antioxidants, higher content of conjugated dienes, conformational alterations of apolipoprotein B-100 and lower affinity by LDL receptor in comparison to nLDL. Increased LDL‾ concentrations have been found in subjects with high risk for cardiovascular diseases, including those with familiar hypercholesterolemia, diabetes and hyperlipidemia. Considering that the mechanisms involved in the endogenous generation of LDL‾ are not yet well elucidated, in this study the effect of glucoxidation and lipolysis of LDL particles was investigated in order to evaluate their contribution to in vitro e in vivo LDL‾ formation. LDL chemical modifications and its reactivity towards a monoclonal anti-LDL‾ antibody were analyzed before and after incubation of either plasma or LDL with lipoprotein lipase (LPL) or phospholipase A2 (PLA2) as an in vitro lipolysis biomimetic system. Moreover, in vivo lipolysis was monitored at the post-prandial period in normolipidemic subjects to investigate LDL‾ endogenously formed. The contribution of glucoxidation to LDL‾ generation was evaluated in vitro by incubating LDL with glucose. The effect of endogenous glucoxidation was monitored by ex-vivo measurement of advanced glycation end products (AGES) and LDL‾ in blood plasma of type I (DM I) and II (DM II) diabetic patients, as well as, in subjects with glucose intolerance (IGT). The in vitro non-enzymatic glycation resulted in increased LDL‾ formation. The DM I, DM II and IGT groups showed higher LDL‾ concentrations than the respective control groups, while AGEs were increased only in DM I e DM II groups. The in vitro lipolysis mediated by LPL and PLA2 induced a significant increase of LDL‾; however, only LPL action was also associated to LDL oxidative modification. In accordance, in vivo lipolysis (post-prandial) also promoted a significant increase of LDL‾ levels associated to LDL oxidative modification. In conclusion, our data show that both, glycoxidation and lipolysis, could contribute to in vivo LDL‾generation.

A fração plasmática da lipoproteína de baixa densidade (LDL) é formada por partículas de diferentes tamanhos, carga e densidade. Baseada na diferença de carga das partículas, a LDL pode ser subfracionada em LDL nativa (nLDL) e LDL eletronegativa (LDL‾). A LDL‾ está presente no plasma e possui propriedades aterogênicas e pró-inflamatórias, assim como, possui menor concentração de antioxidantes lipossolúveis, maior concentração de dienos conjugados, alterações conformacionais da apoliproteína B-100 e menor afinidade para o receptor da LDL em comparação com a nLDL. Concentrações elevadas de LDL‾ têm sido observadas em pacientes com alto risco para o desenvolvimento de doenças cardiovasculares, incluindo hipercolesterolemia familiar, diabetes. Considerando-se que os mecanismos envolvidos na formação endógena da LDL‾ ainda não estão elucidados, neste estudo foi investigado o efeito da glicoxidação e da lipólise sobre a partícula LDL para avaliar a contribuição destes processos para a formação da LDL‾ in vitro e in vivo. As modificações químicas da LDL e da imunorreatividade com anticorpo monoclonal anti-LDL‾ foi analisada antes e depois da incubação do plasma com lipoproteína lipase (LPL) ou fosfolipase A2 (PLA2), assim como mimetizando-se a lipólise intravascular. Além disso, na lipólise in vivo foi monitorado no periodo pós-prandial em indivíduos normolipidêmicos para investigar a LDL‾ formada endogenamente. A contribuição da glicoxidação para a geração de LDL‾ foi avaliada in vitro pela incubação da LDL com glicose. O efeito da glicoxidação endógena foi monitorada pela medida, ex-vivo, dos os produtos de glicação avançada (AGEs) e LDL‾ no plasma de pacientes diabéticos tipo I (DM I), tipo II (DM II) e indivíduos intolerantes à glicose (IGT). O processo de glicação não enzimática, in vitro, resultou no aumento da concentração de LDL‾. Os indivíduos dos grupos DM I, DM II e IGT apresentaram concentrações plasmáticas elevadas de LDL‾ em relação aos seus respectivos controles, enquanto observou-se aumento de AGEs apenas nos grupos DM I e DM II. O processo de lipólise in vitro mediado pela LPL e PLA2, induziu aumento significante da concentração de LDL‾; entretanto, somente pela ação da LPL foi associada com modificações oxidativas. Em concordância, o processo de lipólise in vivo (pós-prandial) também promoveu aumento significativo da concentração de LDL‾ associado com modificações oxidativas. Conclusão, nossos dados mostram que, glicoxidação e de lipólise, poderiam contribuir na formação da LDL‾ in vivo. / The low density lipoprotein (LDL) fraction in blood plasma is formed by particles with different size, charge and density. Based on particle charge differences, LDL fraction may be separated into native (nLDL) and electronegative (LDL‾) subfractions. LDL‾ is present in blood plasma and has atherogenic and proinflammatory properties, as well as, lower concentrations of lipid soluble antioxidants, higher content of conjugated dienes, conformational alterations of apolipoprotein B-100 and lower affinity by LDL receptor in comparison to nLDL. Increased LDL‾ concentrations have been found in subjects with high risk for cardiovascular diseases, including those with familiar hypercholesterolemia, diabetes and hyperlipidemia. Considering that the mechanisms involved in the endogenous generation of LDL‾ are not yet well elucidated, in this study the effect of glucoxidation and lipolysis of LDL particles was investigated in order to evaluate their contribution to in vitro e in vivo LDL‾ formation. LDL chemical modifications and its reactivity towards a monoclonal anti-LDL‾ antibody were analyzed before and after incubation of either plasma or LDL with lipoprotein lipase (LPL) or phospholipase A2 (PLA2) as an in vitro lipolysis biomimetic system. Moreover, in vivo lipolysis was monitored at the post-prandial period in normolipidemic subjects to investigate LDL‾ endogenously formed. The contribution of glucoxidation to LDL‾ generation was evaluated in vitro by incubating LDL with glucose. The effect of endogenous glucoxidation was monitored by ex-vivo measurement of advanced glycation end products (AGES) and LDL‾ in blood plasma of type I (DM I) and II (DM II) diabetic patients, as well as, in subjects with glucose intolerance (IGT). The in vitro non-enzymatic glycation resulted in increased LDL‾ formation. The DM I, DM II and IGT groups showed higher LDL‾ concentrations than the respective control groups, while AGEs were increased only in DM I e DM II groups. The in vitro lipolysis mediated by LPL and PLA2 induced a significant increase of LDL‾; however, only LPL action was also associated to LDL oxidative modification. In accordance, in vivo lipolysis (post-prandial) also promoted a significant increase of LDL‾ levels associated to LDL oxidative modification. In conclusion, our data show that both, glycoxidation and lipolysis, could contribute to in vivo LDL‾generation.