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Thesis advisor: Stephanie C. Berzin / The primary aim of this study was to determine if various typologies of psychiatric diagnoses and patterns of comorbidity are differentially related to the medical lethality of adolescent suicide attempts. The secondary aim was to determine if the relationship between psychopathological comorbidity and suicide attempt lethality is significantly different across gender, age, and race in adolescents. To investigate these relationships, psychiatric evaluations were reviewed for all adolescents that presented to Children's Hospital Boston (CHB) from 2006 to 2010 for a suicide attempt (N = 375). Bivariate and OLS regression analyses were used to test hypotheses. Bivariate results showed that attempters diagnosed with a Substance Abuse Disorder comorbid with any other disorder had higher levels of suicide attempt lethality than those without the diagnosis. Additionally, having Bipolar or Mood Disorder NOS in combination with either Substance Abuse alone or Substance Abuse and Disruptive Disorders had a significant positive relationship with suicide attempt lethality when compared to other comorbidity patterns. In OLS regression, having Substance Abuse comorbid with any other disorder was the only significant diagnostic predictor of lethality. Female gender did not have a significant relationship with lethality. Age group was not predictive of lethality in regression analysis. African-American/Black race had a negative relationship with lethality in bivariate and multivariate analyses. Study findings have important implications for practice, policy, and future research with suicidal adolescents. Results suggest that improvements in the assessment and treatment of substance abuse in suicidal adolescents can play a critical role in decreasing the adolescent suicide rate. Screening for symptoms other than depression, such as substance use, will be critical to effective suicide prevention practices. Future research should focus on the development of effective treatment strategies with suicidal adolescent substance abusers, and aim for a better understanding of suicidal behaviors of adolescents with comorbid bipolar and substance abuse diagnoses. In order to further develop prevention and treatment strategies with this population, policies must be initiated that will support their advancement. / Thesis (PhD) — Boston College, 2011. / Submitted to: Boston College. Graduate School of Social Work. / Discipline: Social Work.

>Magister Scientiae - MSc / Pelargonium capitatum is a plant that is popular in essential oils. The isolated essential oil constituents from the flowers and leaves of the plant were obtained by hydrodistillation followed by GC-MS analysis. The following essential constituents were obtained in abundance from flowers and leaves 8, 11-octadecadienoic acid and citronellol, caryophyllen, α-cubebene, copaene, azulene, pentacosane, 9, 12- octadecadienoic acid. Crude extracts from Pelargonium capitatum were fractionated through various chromatographic techniques in order to achieve satisfactory separations. Four compounds were characterized and the structural elucidation were unambiguously confirmed by spectroscopic methods including one and two-dimensional nuclear magnetic resonance and high resolution mass spectroscopy. The compounds were isolated from the ethyl acetate (2) and hexane (2) extracts, respectively. The four isolates were identified as quercetin, quercetin xylopyranoside, β-sitosterol and undecaprenol. The isolate and the different extracts were tested for cytotoxicity using brine shrimp lethality test. The results showed that quercetin and the extracts were active with hexane extract showed the highest cytotoxicity level of 1.5μg/ml. To the best of our knowledge quercetin xylopyranoside, β-sitesterol and undecaprenol compounds are reported for the first time from Pelargonium capitatum.

This study investigates the impact of traffic patterns and the availability of emergency medical services on the lethality of violent interpersonal encounters. Key situational and contextual factors are controlled using the criminal events perspective. Data were taken from the 2002 National Incident-Based Reporting System of the FBI, as well as from fire/rescue and EMS services of Memphis, TN, Cincinnati, OH, and Richmond, VA. Additive models of logistic regression analysis revealed that fire/rescue availability, firearm use, incidents arising out of arguments, outdoor locations, and victim gender are the most consistent predictors of whether or not a violent incident will result in a homicide.

By 2030, the global colorectal cancer burden is projected to approximately double. This highlights the immediate need to expand our understanding of the etiological origins of colorectal cancer, so that novel therapeutic strategies can be identified and validated. The putative tumor suppressor gene RNF20 encodes a histone H2B mono-ubiquitin ligase and has been found altered/mutated in colorectal and numerous other cancer types. Several studies suggest that RNF20, and by extension mono-ubiquitinated histone H2B (H2Bub1), play important roles in maintaining genome stability in human cells. Indeed, hypomorphic RNF20 expression and/or function have been shown to underlie several phenotypes consistent with genome instability, making aberrant RNF20 biology a potential driver in oncogenesis. Through an evolutionarily conserved trans-histone pathway, RNF20 and H2Bub1 have been shown to modulate downstream di-methylation events at lysines 4 (H3K4me2) and 79 (H3K79me2) of histone H3. Accordingly, understanding the biology associated with RNF20, H2Bub1, H3K4me2, and H3K79me2 is an essential preliminary step towards understanding the etiological origins of cancer-associated RNF20 alterations and identifying a novel therapeutic strategy to selectively kill RNF20-deficient cancers. In this thesis, I employ single-cell imaging, and multiple biochemical techniques to investigate the spatial and temporal patterning and characterize the biology of RNF20, H2Bub1, H3K4me2 and H3K79me2 throughout the cell cycle. In addition, I employ the CRISPR-Cas9 genome editing system to generate RNF20-deficient HCT116 cells. Finally, I employ synthetic lethal strategies to selectively kill RNF20-depleted cells. In conclusion, the research chapters contained within this thesis have characterized putative drivers in cancer (Chapter 3), generated a valuable research reagent for CRISPR-Cas9 ii genome editing experiments (Chapter 4), and identified a novel therapeutic strategy to selectively kill certain cancer cells (Chapter 5). This thesis has increased our understanding of the etiological origins of cancer and generated novel reagents and treatments strategies that after further validation and clinical studies, could be employed to reduce morbidity and mortality rates associated with cancer. / October 2016

A Leishmaniose Visceral (LV) é uma doença infecciosa de carater sistêmico. Estima-se que 350 milhões de pessoas no mundo estão expostas ao risco de infecção, com uma prevalência de 12 milhões de infectados e letalidade mundial de 59.000 casos por ano (OMS), sendo que 90%dos casos de LV ocorrem em países onde existe grande parte da população em situação de pobreza.Na América Latina a maioria dos casos ocorre no Brasil (96%) com média de 3.500 casos/ano. As áreas de maior endemia encontram-se nas regiões mais carentes do Norte e Nordeste.A donça afeta animais e o homem, podendo levar ao óbito em 100% dos casos, tendo como seu principal vetor a Lutzomyia longipalpis e como agente etiológico, a Leishmania Infantum. O Estado do Tocantins apresenta elevado número de casos autóctones, e é considerada área endêmica pelo Minisério da Saúde devido a doença estar presente na maioria dos seus municípios. A cidade de Araguaína, com 55,8% dos casos do Tocantins, é classificada pelo Ministério da Saúde como área de transmissão intensa.O objetivo geral deste trabalho foi analisar casos confirmados de Leishmaniose visceral grave CID-B55 internados no Hospital de Doenças Tropicais do Tocantins (HDT), na cidade de Araguaína - TO que evoluíram para óbito no periodo de janeiro de 2002 a dezembro de 2015. Pretendeu-se identificar e descrever dados epidemiológicos, clínicos e laboratoriais, e variáveis relacionadas ao tratamento. Foi feito um estudo epidemiológico, observacional, retrospectivo, descritivo, utilizando dados secundários de prontuários médicos de pacientes internados, no Hospital de Doenças Tropicais do Estado do Tocantins, na cidade de Araguaína - TO. Resultados: sexo masculino, 60,8 e 39,2% sexo feminino. 49,2% idade entre 0 e 10 anos; 20% maiores de 51 anos. Local de procedência em relação ao município 40,9% são de Araguaína; e ao Estado a 89% são do Tocantins. Presença de febre em 70,8%; esplenomegalia e hepatomegalia 76,7%. Hemoglobina < 7g/dl 50%, plaquetopenia 76,7%;leucopenia 50% e hipoalbuminemia 84,9%.Tempo de febre até a internação > que 30 dias 30,8%; Tempo de diagnóstico 5,1 dias; tempo de diagnóstico ao óbito 11,6 dias; RIFI 1/80 em 53,3%; Teste Rápido positivo 88,2% droga de escolha para tratmento foi Glucantime 43% seguida por anfotericina 32% e anfotericina lipossomal 25%. A principal causa do óbito na DO(Declaração de aÓbito) foi kalazar 33,3% e também Infecções respiratorias 31,7%.Conclui-se que a maior incidencia ocorre em individuo do sexo masculino menores de 10 anos, residentes no Estado do Tocantins, apresentando quadro febril prolongado, anemia severa e hipoalbuminemia grave, podendo este quadro ter influenciado na evolução ao óbito. / American Visceral Leishmaniasis (AVL) is an infectious disease of a systemic nature. It is estimated that 350 million people worldwide are at risk of infection, with a prevalence of 12 million infected and worldwide lethality of 59,000 cases per year (WHO), with 90% of cases of VL occurring in countries where there is of the population living in poverty. In Latin America, most cases occur in Brazil (96%) with an average of 3,500 cases / year. The most endemic areas are in the poorest regions of the North and Northeast, affecting animals and man, and can lead to death in 100% of cases, having as its main vector Lutzomyia longipalpis and as an etiological agent, Leishmania Infantum. The State of Tocantins presents a high number of autochthonous cases, considered an area endemic by the Ministry of Health because the disease is present in most of its municipalities. The city of Araguaína, with 55.8% of the Tocantins cases, is classified by the Ministry of Health as an intense transmission area. The general objective was to analyze confirmed cases of severe visceral leishmaniasis ICD-B55 hospitalized at the Tropical Diseases Hospital of Tocantins (HDT), in the city of Araguaína - TO, which evolved to death in the period from January 2002 to December 2015. The aim was to identify and describe epidemiological, clinical and laboratory data, and treatment-related variables. Study was an epidemiological, observational, retrospective, descriptive study, using secondary data from medical records of hospitalized patients, at the Tropical Diseases Hospital of the State of Tocantins, in the city of Araguaína - TO. Results: male, 60.8% and 39.2% female. 49.2% age between 0 and 10 years; 20% greater than 51 years. Place of origin in relation to the municipality 40.9% are from Araguaína; And to the State, 89% are from Tocantins. Presence of fever in 70.8%; Splenomegaly and hepatomegaly 76.7%. Hemoglobin <7g/dl 50%, thrombocytopenia 76.7%, leukopenia 50% and hypoalbuminemia 84.9%. Fever time until hospitalization > 30 days 30.8%; Diagnostic time 5.1 days; Diagnostic time at death 11.6 days; RIFI 1/80 53.3% Positive Fast test 88,2%; drug of choice for Glucantime treatment 43% followed By amphotericin 32% and liposomal amphotericin 25%. The main cause of the OD was kalazar 33,3% followed by respiratory infections 31.7%. It is concluded that the highest incidence occurs in a male under 10 years of age, living in the state of Tocantins, presenting a prolonged febrile condition, severe anemia and severe hypoalbuminemia, which may have influenced the evolution to death.

In recent years, LIM domains-containing protein 1 (LIMD1) has been identified as a critical component in microRNA (miRNA)-induced silencing complex (miRISC) to regulate miRNA-mediated gene silencing. Human Argonaute (AGO) 2 with its family members (AGO1-4) are critical for the biogenesis of miRNA and thus miRNA-mediated gene silencing. In this study, we have investigated the direct interaction interfaces between LIMD1 and AGO2. A distinct interface within LIMD1, amino acid (a.a) 140-166, is identified to be responsible for the binding to AGO2 and other members of AGO family. Furthermore, the Linker-2 (L2) domain within AGO2 is identified to be responsible for LIMD1 binding and its dependency on the phosphorylation at serine 387 (S387) residue within the L2 domain of AGO2. The phospho-mimic mutant (S387E) enhances the binding of AGO2 to LIMD1, whereas the phospho-deficient mutant (S387A) attenuates AGO2-LIMD1 interaction. In addition, the association of LIMD1 with other AGOs is also dependent on the phosphorylation at the equivalent conserved serine residue within the L2 domain on other AGOs. In addition to the above aspects, LIMD1 is a tumour suppressor gene frequently down-regulated in more than 75% human lung tumours. Because of their loss of expressions or functions, it is of the inherent difficulty in targeting tumour suppressor genes to treat cancers. In this study, the concept of synthetic lethality was used to identify possible protein kinases, the ablation of which are synthetically lethal to LIMD1 negative cancer cell lines. As a result, drugs that target these kinases may represent novel targeted therapies for LIMD1 negative lung tumours. ACVR2B and STK39 are validated to be synthetically lethal with LIMD1 loss. Additionally, the complete loss of LIMD1 expression causes a dramatic increase of STK39 expression due to miRNA-mediated gene silencing pathway. The inverse relationship between LIMD1 and STK39 may represent a conserved and fundamental signalling response and may be a predictive marker for STK39-targeted therapy.

Os Papilomavírus Humanos (HPV) são vírus de DNA, não envelopados que infectam as células epiteliais. A infecção persistente por alguns tipos de HPV é o principal fator de risco para o desenvolvimento do câncer cervical. A maquinaria de reparo de DNA desempenha um papel essencial em várias fases do ciclo de vida do HPV e é crucial para a sobrevivência de células tumorais. Durante a transformação maligna, as oncoproteínas E6 e E7 de HPV são capazes de induzir alterações cromossômicas e numéricas, além de modular a resposta de danos ao DNA. Estas observações sugerem que a maquinaria celular de reparo de dano ao DNA podem desempenhar um papel duplo na biologia do HPV e na sua patogênese. No presente estudo, procurou-se investigar o papel das proteínas de reparo de DNA na biologia das células derivadas de câncer cervical. A fim de alcançar este objetivo, a expressão de 189 genes foi silenciada em células HeLa (HPV 18) e em células SiHa (HPV16), bem como em queratinócitos humanos primários (QHP), utilizando vetores lentivirais que expressam shRNAs específicos. O efeito do silenciamento gênico foi determinado por ensaios de viabilidade celular, análise de proliferação celular, ensaio clonogênico e de formação de colônias em soft ágar. Observamos que o silenciamento dos genes ATM, BRCA1, CHEK2 e HMGB1 reduziu a taxa de crescimento celular, o potencial de crescimento em colônia e a capacidade de crescimento independente de ancoragem das linhagens celulares derivadas de câncer cervical transformadas por HPV, sem afetar QHP. O tratamento das linhagens celulares com fármacos capazes de inibir a atividade das proteínas ATM e CHEK2 revelou uma maior sensibilidade das células tumorais à inibição destas proteínas quando comparadas a QHP. Além disso, mostramos que QHP que expressavam E6E7 ou somente E6 de HPV16 foram mais sensíveis a estes inibidores, quando comparados ao controle QHP ou QHP expressando apenas E7. Além disso, QHP que expressavam mutantes de E6 de HPV16, defectivos para a degradação de p53, foram menos sensíveis do que QHP, que expressavam HPV16 E6 selvagem. Desta forma, estes resultados indicam que estes genes são necessários para a sobrevivência de células transformadas por HPV. Além disso, os nossos resultados sugerem que este efeito está relacionado com a expressão oncoproteína de HPV16 E6 e a sua capacidade para degradar p53. / Human Papillomaviruses (HPV) are non-enveloped DNA viruses that infect epithelial cells. Persistent infection with some HPV types is the main risk factor for the development of cervical cancer. DNA repair machinery plays an essential role in several stages of the HPV life cycle and is crucial for tumor cells survival. During malignant transformation, HPV E6 and E7 oncoproteins induce structural and numerical chromosome alterations and modulate DNA damage response. These observations suggest that cellular DNA repair machinery may play a dual role in both HPV biology and pathogenesis. In the present study, we sought to investigate the role of DNA repair proteins in cervical cancer derived cells biology. In order to achieve this goal, the expression of 189 genes was silenced in HeLa (HPV18) and SiHa (HPV16) cells as well as in primary human keratinocytes (PHK) using lentiviral vectors expressing specific shRNA. The effect of gene silencing was determined by cell viability assay, cell growth analysis, clonogenic and soft agar colony formation test. We observed that ATM, BRCA1, CHEK2 and HMGB1 down-regulation decreased growth rate, clonogenic potential and cellular anchorage-independent growth of HPV-transformed cervical cancer-derived cell lines with no effect in normal keratinocytes. Treatment of cells with drugs that inhibit ATM and CHEK2 activity showed that tumor cells are more sensitive to the inhibition of these proteins than PHK. Besides, we show that PHK expressing HPV16 E6 alone or along with HPV16 E7 were more sensitive to these inhibitors than control PHK or PHK expressing only E7. Moreover, PHK expressing E6 mutants defective for p53 degradation were less sensitive than PHK expressing E6wt. Moreover, to potentiate the effect observed by the ATM and CHEK2 inhibition, we treated cells lines with Doxorubicin and Cisplantin. We observed that tumor cells lines and PHK expressing HPV16 E6 or HPV16 E6/E7 were more sensitive to DNA damage induction. Altogether, these results indicated that these genes are required for HPV-transformed cells survival. Besides, our results suggest that this effect is related to HPV16 E6 oncoprotein expression and its capacity to degrade p53.

Cancer is the second leading cause of death in the USA, following cardiovascular disease. Treating cancer using conventional therapies is associated with low response rates and high toxicity, because these therapies usually lack specific tumor accumulation. Loading anticancer drugs into intelligently designed polymeric nanoparticles (NPs) can serve in delivering these drugs specifically to the tumor site, thus boosting their efficacy and reducing any associated off target toxicity. Targeting NPs to the tumor site can occur through either passive or active means. In passive targeting, NPs of specific size and surface characteristics can exploit the tumor’s erratic vasculature and occluded lymphatic drainage to extravasate the systemic circulation and accumulate preferentially at the tumor site. Active targeting mandates grafting the surface of NPs with a ligand that specifically interacts with a protein expressed at higher levels at the tumor site, in comparison to elsewhere in the body. In the current research, we independently investigated the utilization of passive and active targeting strategies to treat aggressive forms of cancer. Initially, passively targeted poly(lactic-co-glycolic acid) (PLGA) NPs to treat aggressive forms of endometrial cancer (EC) were investigated. A novel combination of soluble paclitaxel (PTX), a first line chemotherapy for EC, and soluble BIBF1120 (BIBF, nintedanib), an antiangiogenic molecular inhibitor, was first tested against three EC cell lines bearing different p53 mutations. The results showed that only EC cells with loss of function (LOF) p53 were sensitive to the combination therapy, indicating the potential of this combination to engender synthetic lethality to PTX. Next, NPs loaded with PTX were investigated with respect to the impact of varying the polymer lactic acid to glycolic acid ratio and the surfactant type on the major physicochemical properties of the prepared nanoparticles, drug loading, cellular uptake, cytotoxicity, and drug release. The optimum formulation was then loaded with BIBF and the combination of independently loaded passively targeted NPs were further evaluated for in vivo activity against a xenograft model of LOF p53 EC. The combination of independently loaded NPs exhibited the highest reduction in tumor volume and prolonged survival when compared to soluble PTX, PTX NPs or untreated control. These data highlight this specific combination of NPs as a novel promising therapy for LOF p53 EC. In a second study, the use of actively targeted NPs to treat liver cancer was explored. In this study, a combination of small interfering RNA (siRNA) against astrocyte elevated gene-1 (AEG-1), and all-trans retinoic acid (ATRA) was investigated as a new therapy for hepatocellular carcinoma (HCC). AEG-1 is a highly expressed oncogene that is directly involved in HCC progression and aggressiveness, in addition to reducing the ability of retinoic acid to induce apoptosis in HCC cells. First, a new conjugate was synthesized that was capable of delivering siRNA selectively to HCC cells, using galactose as a targeting moiety. The conjugate was prepared by linking poly(amidoamine) (PAMAM) dendrimers, polyethylene glycol (PEG) and lactobionic acid (Gal, disaccharide containing galactose) (PAMAM-PEG-Gal). We confirmed the synthesis of the conjugate using 1H-NMR, Mass spectrometry and Matrix-Assisted Laser Desorption/Ionization (MALDI) Mass Spectrometry. Next, nanoplexes of the synthesized conjugate, PAMAM-PEG-Gal, and AEG-1 siRNA were prepared. Nanoplexes were further characterized for their size, surface charge, morphology, and electrophoretic mobility to identify the optimum complexation ratio between PAMAM-PEG-Gal and the siRNA. Then, mice bearing orthotopic luciferase expressing HCC cells were treated with the optimum nanoplex formulation. Results showed that a combination of AEG-1 nanoplexes and ATRA results in a significant reduction in luciferase expression, reduced liver weight, lower AEG-1 mRNA levels and increased apoptosis, when compared to utilizing nanoplexes with silencing control (siCon), siCon+ATRA, or AEG-1 nanoplexes alone. The results indicate that the combination of liver-targeted AEG-1 nanoplexes and ATRA may be a potential treatment for aggressive HCC. These data place targeted NPs as a promising efficient delivery system for cancer treatment.

Unique among the intracellular lipid binding proteins, acyl CoA binding protein (ACBP) exclusively binds long chain fatty acyl CoAs (LCFA-CoAs). To test if ACBP is an essential protein in mammals, the ACBP gene was ablated by homologous recombination in mice. While ACBP heterozygotes appeared phenotypically normal, intercrossing of the heterozygotes did not result in any live homozygous deficient (null) ACBP^(-/-) pups. Heterozygous and wild type embryos were detected at all postimplantation stages, but no homozygous ACBP null embryos were obtained– suggesting that an embryonic lethality occurred at a preimplantation stage of development, or that embryos never formed. While ACBP null embryos were not detected at any blastocyst stage, ACBP null embryos were detected at the morula (8- cell), cleavage (2-cell), and zygote (1-cell) preimplantation stages. Two other LCFACoA binding proteins, sterol carrier protein-2 (SCP-2) and sterol carrier protein-x (SCPx) were significantly upregulated at these stages. These findings demonstrate for the first time that ACBP is an essential protein required for embryonic development and its loss of function may be initially compensated by concomitant upregulation of two other LCFA-CoA binding proteins only at the earliest preimplantation stages. The fact that ACBP is the first known intracellular lipid binding protein whose deletion results in embryonic lethality suggests its vital importance in mammals.