CELL POLARITY REGULATES ORGAN GROWTH THROUGH THE HIPPO PATHWAY

Defects in apical-basal cell polarity and abnormal expression of cell polarity determinants are linked to human cancer. Loss of polarity is highly correlated with malignancy. In Drosophila, perturbation of apical-basal polarity, including overexpressing the apical determinant Crumbs, can lead to uncontrolled tissue growth. Cells mutant for the basolateral determinant scribble overproliferate and can form neoplastic tumors. Interestingly, scribble mutant clones that arise in wild-type tissues are eliminated and therefore do not manifest their tumorigenic potential. However, the mechanisms by which cell polarity coordinates with growth control pathways in developing organs to achieve appropriate organ size remain obscure. To investigate the function of apical determinants in growth regulation, I investigated the mechanism by which the apical determinant Crumbs affects growth in Drosophila imaginal discs. I found that crumbs gain and loss of function cause overgrowth and induction of Hippo target genes. In addition, Crumbs is required for the proper localization of Expanded, an upstream component of the Hippo pathway. Furthermore, we uncoupled the cell polarity and growth control function of Crb through structure-functional analysis. Taken together, our data identify a role of Crb in growth regulation specifically through modulation of the Hippo pathway. To further explore the role of polarity in growth control, I investigated how cells mutant for basolateral determinants are eliminated by using patches of cells mutant for scribble (scribble mutant clones) as a model system. We found that competitive cell-cell interactions eliminate tumorigenic scribble cells by modulation of the Hippo pathway. The regulation of Hippo signaling is required and sufficient to restrain the tumorous growth of scribble mutant cells. Artificially increasing the relative fitness of scribble mutant cells unleashes their tumorigenic potential. Therefore, we have identified a novel tumor-suppression mechanism that depends on signaling between normal and tumorigenic cells. These data identify evasion of cell competition as a critical step toward malignancy and illustrate a role for wild-type tissue in eliminating abnormal cells and preventing the formation of tumors.

The Role of Acidic Fibroblast Growth Factor and Fibroblast Growth Factor Receptor 4 in High Grade Serous Carcinoma

Background: High grade serous carcinoma whether ovarian, tubal or primary peritoneal, continues to be the most lethal gynecologic malignancy in the USA. Although combination chemotherapy and aggressive surgical resection has improved survival in the past decade the majority of patients still succumb to chemo-resistant disease recurrence. It has recently been reported that amplification of 5q31-5q35.3 is associated with poor prognosis in patients with high grade serous ovarian carcinoma. Although the amplicon contains over 50 genes, it is notable for the presence of several members of the fibroblast growth factor signaling axis. In particular acidic fibroblast growth factor (FGF1) has been demonstrated to be one of the driving genes in mediating the observed prognostic effect of the amplicon in ovarian cancer patients. This study seeks to further validate the prognostic value of fibroblast growth receptor 4 (FGFR4), another candidate gene of the FGF/FGFR axis located in the same amplicon. The emphasis will be delineating the role the FGF1/FGFR4 signaling axis plays in high grade serous ovarian carcinoma; and test the feasibility of targeting the FGF1/FGFR4 axis therapeutically. Materials and Methods: Spearman and Pearson correlation studies on data generated from array CGH and transcriptome profiling analyses on 51 microdissected tumor samples were used to identify genes located on chromosome 5q31-35.3 that showed significant correlation between DNA and mRNA copy numbers. Significant correlation between FGF1 and FGFR4 DNA copy numbers was further validated by qPCR analysis on DNA isolated from 51 microdissected tumor samples. Immunolocalization and quantification of FGFR4 expression were performed on paraffin embedded tissue samples from 183 cases of high-grade serous ovarian carcinoma. The expression was then correlated with clinical data to assess impact on survival. The expression of FGF1 and FGFR4 in vitro was quantified by real-time PCR and western blotting in six high-grade serous ovarian carcinoma cell lines and compared to those in human ovarian surface epithelial cells to identify overexpression. The effect of FGF1 on these cell lines after serum starvation was quantified for in vitro cellular proliferation, migration/invasion, chemoresistance and survival utilizing a combination of commercially available colorimetric, fluorometric and electrical impedance assays. FGFR4 expression was then transiently silenced via siRNA transfection and the effects on response to FGF1, cellular proliferation, and migration were quantified. To identify relevant cellular pathways involved, responsive cell lines were transduced with different transcription response elements using the Cignal-Lenti reporter system and treated with FGF1 with and without transient FGFR4 knock down. This was followed by western blot confirmation for the relevant phosphoproteins. Anti-FGF1 antibodies and FGFR trap proteins were used to attempt inhibition of FGF mediated phenotypic changes and relevant signaling in vitro. Orthotopic intraperitoneal tumors were established in nude mice using serous cell lines that have been previously transfected with luciferase expressing constructs. The mice were then treated with FGFR trap protein. Tumor progression was then followed via bioluminescent imaging. The FGFR4 gene from 52 clinical samples was sequenced to screen for mutations. Results: FGFR4 DNA and mRNA copy numbers were significantly correlated and FGFR4 DNA copy number was significantly correlated with that of FGF1. Survival of patients with high FGFR4 expressing tumors was significantly shorter that those with low expression(median survival 28 vs 55 month p< 0.001) In a multivariate cox regression model FGFR expression significantly increased risk of death (HR 2.1, p<0.001). FGFR4 expression was significantly higher in all cell lines tested compared to HOSE, OVCA432 cell line in particular had very high expression suggesting amplification. FGF1 was also particularly overexpressed in OVCA432. FGF1 significantly increased cell survival after serum deprivation in all cell lines. Transient knock down of FGFR4 caused significant reduction in cell migration and proliferation in vitro and significantly decreased the proliferative effects of FGF1 in vitro. FGFR1, FGFR4 traps and anti-FGF1 antibodies did not show activity in vitro. OVCA432 transfected with the cignal lenti reporter system revealed significant activation of MAPK, NFkB and WNT pathways, western blotting confirmed the results. Reverse phase protein array (RPPA) analysis also showed activation of MAPK, AKT, WNT pathways and down regulation of E Cadherin. FGFR trap protein significantly reduced tumor growth in vivo in an orthotopic mouse model. Conclusions: Overexpression and amplification of several members of the FGF signaling axis present on the amplicon 5q31-35.3 is a negative prognostic indicator in high grade serous ovarian carcinoma and may drive poor survival associated with that amplicon. Activation of The FGF signaling pathway leads to downstream activation of MAPK, AKT, WNT and NFkB pathways leading to a more aggressive cancer phenotype with increased tumor growth, evasion of apoptosis and increased migration and invasion. Inhibition of FGF pathway in vivo via FGFR trap protein leads to significantly decreased tumor growth in an orthotopic mouse model.

Household Hardships, Public Programs, and Their Associations with the Health and Development of Very Young Children: Insights from Children’s HealthWatch

America’s low-income families struggle to protect their children from multiple threats to their health and growth. Many research and advocacy groups explore the health and educational effects of food insecurity, but less is known about these effects on very young children. Children’s HealthWatch, a group of pediatric clinicians and public health researchers, has continuously collected data on the effects of food insecurity alone and in conjunction with other household hardships since 1998. The group’s peer reviewed research has shown that a number of economic risks at the household level, including food, housing and energy insecurity, tend to be correlated. These insecurities alone or in conjunction increase the risk that a young child will suffer various negative health consequences, including increases in lifetime hospitalizations, parental report of fair or poor health,1 or risk for developmental delays.2 Child food insecurity is an incremental risk indicator above and beyond the risk imposed by household-level food insecurity. The Children’sHealthwatch research also suggests public benefits programs modify some of these effects for families experiencing hardships. This empirical evidence is presented in a variety of public venues outside the usual scientific settings, such as congressional hearings, to support the needs of America’s most vulnerable population through policy change. Children’s HealthWatch research supports legislative solutions to food insecurity, including sustained funding for public programs and re-evaluation of the use of the Thrifty Food Plan as the basis of SNAP benefits calculations. Children’s HealthWatch is one of many models to support the American Academy of Pediatrics’ call to “stand up, speak up, and step up for children.”3 No isolated group or single intervention will solve child poverty or multiple hardships. However, working collaboratively each group has a role to play in supporting the health and well-being of young children and their families. 1. Cook JT, Frank DA, Berkowitz C, et al. Food insecurity is associated with adverse health outcomes among human infants and toddlers. J Nutr. 2004;134:1432-1438. 2. Rose-Jacobs R, Black MM, Casey PH, et al. Household food insecurity: associations with at-risk infant and toddler development. Pediatrics. 2008;121:65-72. 3. AAP leader says to stand up, speak up, and step up for child health [news release]. Boston, MA: American Academy of Pediatrics; October 11, 2008. http://www2.aap.org/pressroom/nce/nce08childhealth.htm. Accessed January 1, 2012.

Implementing the Global Plan of Action on workers' health: Components to protect health care workers

Health care workers are at risk for percutaneous injuries and infection with blood born pathogens due to needle stick injuries with contaminated needles. The most common pathogens transmitted are hepatitis B, and C and HIV/AIDS. According to the WHO Global Plan of Action (GPA) a large gap exist between and within countries with regards to the health status of workers and their exposure to occupational risk. Less than 15% of the world's work forces have access to occupational health services despite the availability of effective interventions that can prevent occupational hazards, or protect and promote health in the workplace. The 2006 World Health Report declared that there is a global crisis in the health care work force. 1 in 400 of the world's health care workers work in Sub-Saharan Africa. 1 in 3 work in the U.S or Canada. The shortage of health care workers is worst in Southeast Asia and Sub-Saharan Africa. These countries have the highest burden of exposure to contaminated sharps. They rarely, if ever monitor the exposure or health impact of occupational ailments and injuries on workers. Many injuries are unreported. Occupational health services in the developing world are virtually non existent. Many health care workers leave their home countries and go to work in other countries where the working conditions, occupational services included, are better. The inability of countries to provide the necessary numbers of health care workers to provide a high level of health coverage is a threat to national and international public health security. Immunizing health care workers against hepatitis B and providing them PEP, PPE, education and safety training is an essential part of increasing and maintaining the numbers of health care workers in the critical shortage areas. ^

THE BACON CHOW STUDY: THE RELATIONSHIP BETWEEN INFECTIOUS ILLNESS AND GROWTH OF INFANTS

Multiple dietary deficiencies and high rates of infectious illness are major health problems leading to malnutrition and limitation of growth of children in developing countries. Longitudinal studies which provide information on illness incidence and growth velocity are needed in order to untangle the complex interrelationship between nutrition, illness and growth. From 1967 to 1973, researchers led by Dr. Bacon Chow of the Johns Hopkins University School of Hygiene undertook a quasi-experimental prospective study in Suilin Township, Taiwan to determine the effects of a nutritional supplement to the diets of pregnant and lactating women on the growth, development and resistance to disease of their offspring. This dissertation presents results from the analysis of infant morbidity and postnatal growth.^ Maternal nutritional supplementation has no apparent effect on the postnatal growth or morbidity of infants. Significant sex differences exist in growth response to illness and in illness susceptibility. Male infants have more diarrhea and upper respiratory illness. Respiratory illness is positively associated with growth rate in weight in the first semester of life. Diarrhea is significantly negatively associated with growth in length in the second semester. Small-for-date infants are more susceptible to illness in general and have a different pattern of growth response than large-for-date infants.^ Principal components analysis of illness data is shown to be an effective technique for making more precise use of ambiguous morbidity data. Multiple regression with component scores is an accurate method for estimating variance in growth rate predicted by indepenent illness variables. A model is advanced in which initial postnatal growth rate determines subsequent susceptibility to nutritional stress and infection. Initial growth rate is a function of prenatal nutrition, but is not significantly affected by maternal supplementation during gestation or lactation. Critical evaluation is made of nutritional supplementation programs which do not afford disease control.^

Evaluating the Harris County TexHealth 3-Share Plan: An exploratory study

An important health issue in the United States today is the large number of people who have problems accessing needed health care because they lack health insurance coverage. Providing health insurance coverage for the working uninsured is a particularly significant challenge in Texas, which has the highest percentage of uninsured in the nation. In response to the low rate of employer-sponsored coverage in the Houston area and the growing numbers of uninsured, the Harris County Health Care Alliance (HCHA) developed and implemented the Harris County 3-Share Plan. A 3-Share Plan is not insurance, but provides health coverage in the form of a benefits package to employers who subscribe to the program and offer it to their employees. ^ A cross sectional study design was conducted to describe 3-Share employer and employee participants and evaluate their outcomes after its first year of operation. Between September and December 2011, 85% of employers enrolled in the 3-Share Plan completed a survey about the affordability of the 3-Share Plan, their satisfaction with the Plan, and the Plan's impact on employee recruitment, retention, productivity, and absenteeism. Forty-five percent of employees enrolled in the 3-Share Plan responded to a survey asking about the affordability of the 3-Share plan, accessibility of health care, availability of providers on the plan, health plan availability, utilization of primary care providers and the ER, and satisfaction with the plan. ^ A summary of the findings shows employers and employees say that they joined the plan because of the low-cost, and once they had participated in the Plan, the majority of employers and employees found that it is affordable for them. The majority of employees say they are getting access easily and without delay, but for those who aren't able to get access, or are delayed, the main cause is related to non-financial barriers to care. Ultimately, employees are satisfied with the 3-Share, and they plan to continue with health coverage under the 3-Share Plan. The 3-Share Plan will keep people in a system of care, and promote health, which will benefit the individuals, the businesses and the community of Harris County.^

Evaluating the Harris County TexHealth 3-Share plan: An exploratory study

An important health issue in the United States today is the large number of people who have problems accessing needed health care because they lack health insurance coverage. Providing health insurance coverage for the working uninsured is a particularly significant challenge in Texas, which has the highest percentage of uninsured in the nation. In response to the low rate of employer-sponsored coverage in the Houston area and the growing numbers of uninsured, the Harris County Health Care Alliance (HCHA) developed and implemented the Harris County 3-Share Plan. A 3-Share Plan is not insurance, but provides health coverage in the form of a benefits package to employers who subscribe to the program and offer it to their employees. ^ A cross sectional study design was conducted to describe 3-Share employer and employee participants and evaluate their outcomes after its first year of operation. Between September and December 2011, 85% of employers enrolled in the 3-Share Plan completed a survey about the affordability of the 3-Share Plan, their satisfaction with the Plan, and the Plan's impact on employee recruitment, retention, and productivity. Forty-five percent of employees enrolled in the 3-Share Plan responded to a survey asking about the affordability of the 3-Share plan, accessibility of providers on the plan, satisfaction, and utilization of primary care providers and the ER. ^ A summary of the findings shows employers and employees say that they joined the plan because of the low-cost, and once they had participated in the Plan, the majority of employers and employees found that it is affordable for them. The majority of employees say they are getting access easily and without delay, but for those who aren't able to get access, or are delayed, the main cause is related to non-financial barriers to care. Ultimately, employees are satisfied with the 3-Share, and they plan to continue with health coverage under the 3-Share Plan. The 3-Share Plan will keep people in a system of care, and promote health, which will benefit the individuals, the businesses and the community of Harris County.^