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Title: Identification and Functional Characterization of a Long Non-coding RNA associated with Prostate Cancer.
Creator: Hasan, Md Faqrul, Chakrabarti, Ratna, Zhao, Jihe, Zhang, Shaojie, University of Central Florida
Abstract / Description: Prostate cancer is the most common cancer in men in the western world. Although early stage prostate cancer is treatable late stage, more specifically, metastatic and drug resistant prostate cancers are mostly incurable. The failure of current treatments obligates the research community to explore novel areas in prostate cancer biology and find better therapeutic targets. Emerging evidences show that non-coding RNAs specifically long non-coding RNAs (lncRNAs) play regulatory roles in various...
Show moreProstate cancer is the most common cancer in men in the western world. Although early stage prostate cancer is treatable late stage, more specifically, metastatic and drug resistant prostate cancers are mostly incurable. The failure of current treatments obligates the research community to explore novel areas in prostate cancer biology and find better therapeutic targets. Emerging evidences show that non-coding RNAs specifically long non-coding RNAs (lncRNAs) play regulatory roles in various cellular processes and are frequently dysregulated in cancer including prostate cancer. These aberrantly expressed lncRNAs mostly with unexplored genetic information may drive cancer progression. Previous studies done in our laboratory showed a tumor suppressor role of a cluster of small non-coding RNAs or microRNA (miRNA) miR-17-92a in PC-3 prostate cancer cells. To learn the underlying mechanism, transcriptome analysis with or without expression of miR-17-92a was conducted in our laboratory. RNA-sequencing data analysis identified reduced expression of a set of lncRNAs and oncogenes, and up regulation of several tumor suppressor genes upon expression of miR-17-92a cluster miRNAs. One of the down regulated intergenic lncRNAs, PAINT (Prostate Cancer Associated Intergenic Non-coding Transcript) (LINC00888), was selected for determining its functional role in prostate cancer. TCGA and GEO profiles analyses revealed up regulation of PAINT in prostate tumors with higher Gleason Scores, in highly aggressive metastatic prostate cancer cell lines, and upon androgen deprivation therapy of prostate cancer cells. This observation was supported by our studies on expression analysis of PAINT in prostate tumor tissues using RNA in-situ hybridization in tissue microarrays (TMA) containing tissues from different stages of prostate cancer and normal prostate tissues, which showed higher expression of PAINT in prostate cancer tissues compared to normal tissues. Furthermore, late stage (stage III and stage IV) prostate tumors showed significant overexpression of PAINT compared to early stage (stage II) prostate cancer tissues. We examined the functional relevance of PAINT in promoting tumor progression next using different prostate cancer cell lines. Silencing of PAINT using siRNAs showed decreased cell proliferation, reduced S-phase progression and activation of pro-apoptotic proteins PARP and Caspase-3. Silencing of PAINT also showed decreased cell migration and increased expression of the epithelial marker, E-cadherin while reduced expression of mesenchymal markers Slug and Vimentin. Ectopic expression of PAINT reversed the effects observed upon silencing of PAINT. Increased cell proliferation, cell cycle progression and cell migration were noted in prostate cancer cells overexpressing PAINT. Additionally, cancer promoting phenotype such as larger colony formation and higher expression of mesenchymal marker Slug, was detected upon overexpression of PAINT. Our study also determined the therapeutic benefit of inhibition of expression showing an increased sensitivity of metastatic prostate cancer cells to the chemotherapeutic agent docetaxel (DTX) and selective Aurora kinase inhibitor VX-680. Taken together, our study establishes an oncogenic function of PAINT, its clinical relevance as a marker for advanced stage prostate cancer and its potential as a therapeutic target for metastatic prostate cancer.
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Date Issued: 2019
Identifier: CFE0007466, ucf:52681
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007466

Title: Role of Kruppel-like Factor 8 (KLF8) in Cancer and Cardiomyopathy.
Creator: Lahiri, Satadru, Zhao, Jihe, Parthasarathy, Sampath, Masternak, Michal, Siddiqi, Shadab, University of Central Florida
Abstract / Description: Cancer and cardiovascular diseases are two most fatal diseases causing innumerable death each year. Understanding the mechanisms underlying these diseases is critical for developing proper therapeutic approach. Kr(&)#252;ppel-like factor 8 (KLF8) is a member of Kr(&)#252;ppel-like family transcription factors that is overexpressed in many types of cancers. There is no report on role of KLF8 in cardiovascular diseases to date. KLF8 transcriptionally activates or represses a host of target...
Show moreCancer and cardiovascular diseases are two most fatal diseases causing innumerable death each year. Understanding the mechanisms underlying these diseases is critical for developing proper therapeutic approach. Kr(&)#252;ppel-like factor 8 (KLF8) is a member of Kr(&)#252;ppel-like family transcription factors that is overexpressed in many types of cancers. There is no report on role of KLF8 in cardiovascular diseases to date. KLF8 transcriptionally activates or represses a host of target genes to promote cancer cell proliferation, migration, invasion and epithelial to mesenchymal transition during tumor progression. Studies proposed in this thesis identified a novel posttranslational modification of KLF8 essential for its role in promoting cancer cell migration and discovered a novel function of KLF8 in cardiomyopathy. In our first study, we identified serine 48 (S48) as a novel phosphorylation site on KLF8. Pharmacological and genetic manipulations of various potential kinases further revealed ERK2 as the kinase responsible for this novel phosphorylation. Functional studies indicated that this phosphorylation is crucial for protecting KLF8 protein from degradation in the nucleus and promoting cancer cell migration. Preclinical xenograft models have indicated an important role of KLF8 for tumor progression. To investigate role of KLF8 in spontaneous tumorigenesis better recapitulating pathology in patients, we established the first Cre-regulated conditional KLF8 transgenic mouse model. Upon induction of global expression of the KLF8 transgene, spontaneous mammary and testicular tumors were formed in a small population of the mice by their mid-age, as expected considering the long latency required for tumor progression. Surprisingly, however, nearly 100% of KLF8 the mice died with a significantly enlarged heart, which did not occur to any littermate control mouse. Further characterization of the mice revealed that the global expression of the transgene caused striking systolic dysfunction leading to fatal dilated cardiomyopathy. Importantly, these similar phenotypes were reproduced in heart-specific KLF8 transgenic mice. Cardiovascular disease PCR array identified a number of genes potentially mediating KLF8-induced cardiac pathology. These results identified a previously unimagined function of KLF8 in the heart, shed new light on the mechanisms of cardiac diseases and provide novel preclinical mouse models for future translational research.
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Date Issued: 2016
Identifier: CFE0006692, ucf:51914
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006692

Title: Bone Morphogenetic Protein 7 Inhibits Pyroptotic Cell Death in Vascular Smooth Muscle Cells of Atherosclerotic Apolipoprotein E -/- Mice.
Creator: Garner, Kaley, Singla, Dinender, Zhao, Jihe, Pourmoghadam, Kamal, University of Central Florida
Abstract / Description: Atherosclerosis (ATH) is an inflammation-mediated disease in which cell death underlies the formation of lesions along the intima layer of vascular walls resulting in vessel narrowing, decreased blood flow, and increased risk of lesion rupture leading to myocardial infarction and stroke. The current study was undertaken to investigate whether inflammation in ATH can induce pyroptosis in vascular smooth muscle cells (SMC's). We therefore hypothesized that pyroptosis occurs and is inhibited by...
Show moreAtherosclerosis (ATH) is an inflammation-mediated disease in which cell death underlies the formation of lesions along the intima layer of vascular walls resulting in vessel narrowing, decreased blood flow, and increased risk of lesion rupture leading to myocardial infarction and stroke. The current study was undertaken to investigate whether inflammation in ATH can induce pyroptosis in vascular smooth muscle cells (SMC's). We therefore hypothesized that pyroptosis occurs and is inhibited by bone morphogenetic protein 7 (BMP7). We examined SMC pyroptosis at acute (D5) and midstage (D28) following disturbed flow-induced hemodynamic injury to the vascular wall using our partial left carotid artery ligation (PLCA) model. ApoE -/- mice (11(&)#177;1 week old) were divided into three groups: Sham, PLCA, PLCA+BMP7 (200?g/kg; i.v) and arterial tissue was collected for immunohistochemical staining (IHC) and western blot (WB) analysis. At D5 and D28, IHC data demonstrated that PLCA significantly upregulated Toll-like receptor 4 (TLR4) and NLRP3 inflammasome components (NLRP3 and Caspase-1), indicating the initiation and activation of pyroptosis in SMC's (p(<)0.05). Further, maturation of pro-IL-1? and pro-IL-18 released through cell membrane pores mediated by Caspase-11 were investigated. Our data shows a significant increase at D5 and D28 in IL-1?, IL-18, and Caspase-11 expression following PLCA, which was significantly improved upon treatment with BMP7 (p(<)0.05). Western blot analysis supported these findings demonstrating initiation of pyroptosis via TLR4, upregulation of inflammasome components (Caspase-1 and NLRP3), and release of proinflammatory cytokines, IL-1? and IL-18 at D28, but not at D5. Overall, this study demonstrates that pyroptosis occurs in vascular smooth muscle cells in our PLCA model and that BMP7 administration attenuates pyroptosis significantly.
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Date Issued: 2019
Identifier: CFE0007635, ucf:52472
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007635

Title: A Solid Phase Assay for Topoisomerase I interfacial Poisons and Catalytic Inhibitors.
Creator: Cyril Sagayaraj, Vidusha, Muller, Mark, Zhao, Jihe, Chakrabarti, Debopam, University of Central Florida
Abstract / Description: We report a mechanism based screening technique to rapidly identify eukaryotic topoisomerase I targeting agents. The method is based on genetic tagging of topoisomerase I to immobilize the enzyme on a solid surface in a microtiter well format. DNA is added to the wells and retained DNA is detected by Picogreen fluorescence. Compounds that result in an increase in Picogreen staining represent potential topoisomerase interfacial poisons while those that reduce fluorescence report catalytic...
Show moreWe report a mechanism based screening technique to rapidly identify eukaryotic topoisomerase I targeting agents. The method is based on genetic tagging of topoisomerase I to immobilize the enzyme on a solid surface in a microtiter well format. DNA is added to the wells and retained DNA is detected by Picogreen fluorescence. Compounds that result in an increase in Picogreen staining represent potential topoisomerase interfacial poisons while those that reduce fluorescence report catalytic inhibitors; therefore, the solid phase assay represents a 'bimodal' readout that reveals mechanisms of action. The method has been demonstrated to work with known interfacial poisons and catalytic inhibitors. In addition to specific topoisomerase targeting drugs, the method also weakly detects other relevant anticancer agents, such as potent DNA alkylating and intercalating compounds; therefore, topoisomerase I HTS represents an excellent tool for searching and identifying novel genotoxic agents. This method is rapid, robust, economical and scalable for large library screens.
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Date Issued: 2011
Identifier: CFE0004473, ucf:49304
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004473

Title: Diabetes Phenotypes in Transgenic Pancreatic Cancer Mouse Models.
Creator: Albury, Toya, Altomare, Deborah, Zhao, Jihe, Masternak, Michal, Khaled, Annette, University of Central Florida
Abstract / Description: Protein Kinase B/AKT, a serine/threonine kinase with three isoforms (AKT1-3), is downstream of phosphatidylinositol 3-kinase (PI3K), and signals through the phosphorylation and subsequent activation or inhibition of downstream substrates, such as mammalian target of rapamycin complex 1 (mTORC1) or glycogen synthase kinase 3 beta (GSK-3?), respectively. The AKT1 isoform is predominantly recognized for regulation of cell survival, growth, and proliferation, due to its constitutive activation in...
Show moreProtein Kinase B/AKT, a serine/threonine kinase with three isoforms (AKT1-3), is downstream of phosphatidylinositol 3-kinase (PI3K), and signals through the phosphorylation and subsequent activation or inhibition of downstream substrates, such as mammalian target of rapamycin complex 1 (mTORC1) or glycogen synthase kinase 3 beta (GSK-3?), respectively. The AKT1 isoform is predominantly recognized for regulation of cell survival, growth, and proliferation, due to its constitutive activation in pancreatic cancers (e.g., islet cell carcinoma and pancreatic adenocarcinoma). The progression of pancreatic ductal adenocarcinoma (PDAC), the most lethal common cancer, is initiated by activation mutations of the KRas oncogene. This leads to additional molecular changes, such as activation of the AKT1 oncogene, which drives PDAC progression and tumor formation. By mating transgenic mice with activation of KRas (Pdx- Cre;LSL-KRasG12D) and mice with activation of AKT1 (Pdx- Tta;TetO-MyrAKT1) we were able to produce mice with two activated oncogenes (AKT1Myr/KRasG12D) for comparative studies. Kaplan-Meier survival curves, histology, and genomic/proteomic analysis were used to characterize the incidence and frequency of histological (e.g. presence of mucin-4 in pancreatic intraepithelial neoplasms) and genetic (e.g. loss of tumor suppressors p16Ink4a and p19Arf) alterations known to commonly occur in human pancreatic cancer, as well as delineate the role of AKT1 in accelerating pancreatic tumor progression and metastasis. We determined that AKT1Myr/KRasG12D mice, unlike other PDAC mouse models, accurately mimic the human PDAC progression molecularly, structurally, and temporally. Interestingly, the AKT1Myr and AKT1Myr/KRasG12D models both exhibit a pre-tumor, diabetic phenotype. While, AKT1 hyperactivation in various cancers has been thoroughly studied, its role in glucose metabolism has been noted, but comparatively overlooked. As early as the 1900s a relationship between diabetes and pancreatic cancer has been proposed. With 80% of PDAC patients suffering from hyperglycemia or diabetes prior to diagnosis, one prevailing theory is that new onset diabetes is an early marker for pancreatic cancer. This is also supported by experimental and clinical studies, such as the resolution of diabetes with tumor removal and the induction of hyperglycemia with the implantation of cancer cell lines. To better understand the role of AKT1 and its hyperactivation in glucose metabolism, AKT1Myr mice were characterized via metabolic (e.g. glucose/insulin tolerance test) and histological (e.g. immunohistochemistry) studies. Beginning at weaning, 3 weeks of age, the glucose intolerant AKT1Myr mice exhibited non-fasted hyperglycemia, which progressed to fasted hyperglycemia by 5 months of age. The glucose intolerance was attributed to a fasted hyperglucagonemia, and hepatic insulin resistance detectable by reduced phosphorylation of the insulin receptor following insulin injection into the inferior vena cava. Additionally, AKT1Myr/KRasG12D mice currently being studied, appear to display a more severe diabetic phenotype, with fasted hyperglycemia noticeable at an earlier age, fasted hyperglucagonemia, polyuria, muscle wasting, and bloating. Treatment of both models with doxycycline diet, to turn-off the transgene, caused attenuation of the non-fasted and fasted hyperglycemia, thus affirming AKT1 hyperactivation as the trigger. These newly revealed roles of AKT1, along with future studies of these mouse models, will better delineate the molecular mechanisms responsible for the individual and joint roles of AKT1 and KRas in pancreatic cancer oncogenesis, the initiation of cancer associated diabetes, and the association of these two diseases.
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Date Issued: 2015
Identifier: CFE0006245, ucf:51081
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006245

Title: Cerium Oxide Nanoparticles Sensitize Pancreatic Cancer Cells to Radiation by Promoting Acidic pH, ROS, and JNK Dependent Apoptosis.
Creator: Wason, Melissa, Zhao, Jihe, Self, William, Altomare, Deborah, Baker, Cheryl, University of Central Florida
Abstract / Description: Side effects of radiation therapy (RT) remain the most challenging issue for pancreatic cancer treatment. In this report we determined whether and how cerium oxide nanoparticles (CONPs) sensitize pancreatic cancer cells to RT. CONP pretreatment enhanced radiation-induced reactive oxygen species (ROS) production preferentially in acidic cell-free solutions as well as acidic human pancreatic cancer cells. In acidic environments, CONPs favor the scavenging of superoxide radical over the hydroxyl...
Show moreSide effects of radiation therapy (RT) remain the most challenging issue for pancreatic cancer treatment. In this report we determined whether and how cerium oxide nanoparticles (CONPs) sensitize pancreatic cancer cells to RT. CONP pretreatment enhanced radiation-induced reactive oxygen species (ROS) production preferentially in acidic cell-free solutions as well as acidic human pancreatic cancer cells. In acidic environments, CONPs favor the scavenging of superoxide radical over the hydroxyl peroxide resulting in accumulation of the latter whereas in neutral pH CONPs scavenge both. CONP treatment prior to RT markedly potentiated the cancer cell apoptosis both in culture and in tumors and the inhibition of the pancreatic tumor growth without harming the normal tissues or host mice. Mechanistically, CONPs were not able to significantly impact RT-induced DNA damage in cancer cells, thereby ruling out sensitization through increased mitotic catastrophe. However, JNK activation, which is known to be a key driver of RT-induced apoptosis, was significantly upregulated by co-treatment with CONPs and RT in pancreatic cancer cells in vitro and human pancreatic tumors in nude mice in vivo compared to CONPs or RT treatment alone. Further, CONP-driven increase in RT-induced JNK activation was associated with marked increases in Caspase 3/7 activation, indicative of apoptosis. We have shown CONPs increase ROS production in cancer cells; ROS has been shown to drive the oxidation of thioredoxin (TRX) 1 which results in the activation of Apoptosis Signaling Kinase (ASK) 1. The dramatic increase in ASK1 activation following the co-treatment of pancreatic cancer cells with CONPs followed by RT in vitro suggests that increased the c-Jun terminal kinase (JNK) activation is the result of increased TRX1 oxidation. The ability of CONPs to sensitize pancreatic cancer cells to RT was mitigated when the TRX1 oxidation was prevented by mutagenesis of a cysteine residue, or the JNK activation was blocked by an inhibitor,. Additionally, angiogenesis in pancreatic tumors treated with CONPs and RT was significantly reduced compared to other treatment options. Taken together, these data demonstrate an important role and mechanisms for CONPs in specifically killing cancer cells and provide novel insight into the utilization of CONPs as a radiosensitizer and therapeutic agent for pancreatic cancer.
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Date Issued: 2013
Identifier: CFE0005116, ucf:50725
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005116

Title: Development of Cytotoxic Natural Killer Cells for Ovarian Cancer Treatment.
Creator: Pandey, Veethika, Altomare, Deborah, Zhao, Jihe, Khaled, Annette, Estevez, Alvaro, University of Central Florida
Abstract / Description: Ovarian cancer is a leading cause of gynecological malignancy. Cytoreductive surgery and frontline platinum/taxane-based chemotherapy provides good initial efficacy in the treatment, but poor long-term patient survival. This is mainly caused by tumor relapse due to intraperitoneal spreading and ineffective alternate therapies to treat these resistant tumors. The challenge in the field is to develop strategies that would prove effective in these patients and extend overall survival.Over the...
Show moreOvarian cancer is a leading cause of gynecological malignancy. Cytoreductive surgery and frontline platinum/taxane-based chemotherapy provides good initial efficacy in the treatment, but poor long-term patient survival. This is mainly caused by tumor relapse due to intraperitoneal spreading and ineffective alternate therapies to treat these resistant tumors. The challenge in the field is to develop strategies that would prove effective in these patients and extend overall survival.Over the years, various treatments have been developed for the treatment of cancer amongst which, adoptive cell immunotherapy has shown promising results. But despite the efficacy seen in the clinic, there are concerns with the complexity of treatment and associated side effects. Therefore, there is still a need for better understanding of how different components of the immune system react to the presence of tumor. In this study, healthy human peripheral blood mononuclear cells (PBMCs) were used to examine the immune response in a mouse model with residual human ovarian tumor, where natural killer (NK) cells were found to be the effector cells that elicited an anti-tumor response. Presence of tumor was found to stimulate NK cell expansion and cytotoxicity in mice treated intraperitoneally (IP) with PBMCs+Interleukin-2 (IL- 2). Intravenous (IV) adoptive transfer of isolated NK cells has been attempted in ovarian cancer patients before, but showed lack of persistence in patients resulting in lack of anti-tumor efficacy. Experiments in this study highlight the significance of NK cell-cytotoxic response to tumor, which may be attributed to interacting immune cell types in the PBMC population (when treated IP), as opposed to clinically used isolated NK cells showing lack of anti-tumor efficacy in ovarian cancer patients (when treated IV).iiiNK cell immunotherapy is mainly limited by insufficient numbers generated for adoptive transfer, limited in vivo life span after adoptive transfer, lack of cytotoxicity and some logistical concerns that impede its widespread implementation. Therefore there is a need to develop methods of NK cell expansion that provide stimulation similar to other immune cell types in the PBMC population. The second part of this study utilizes a method of in vivo NK cell expansion using a particle-based approach in which plasma membranes of K562-MB21-41BBL cells (K562 cells expressing membrane-bound IL-21 and 41BB ligand) are used for specific NK cell expansion from PBMCs. NK cells expanded with this method were cytotoxic, showed in vivo persistence and biodistribution in different organs.Collectively, these studies show that NK cells are a major innate immune component that can recognize and kill the tumor. Their cytotoxic ability, using particle-based stimulation, can be enhanced for a second-line treatment of relapsed tumors such as in ovarian cancer as well as other cancer types.
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Date Issued: 2015
Identifier: CFE0006369, ucf:51531
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006369

Title: Neurological profile of older ApoE-PON1 double knockout mice.
Creator: Mitra, Connie, Parthasarathy, Sampath, Kim, Yoon-Seong, Zhao, Jihe, University of Central Florida
Abstract / Description: Atherosclerosis is a cardiovascular disease where plaques made up of lipids in the form of cholesterol ester build up in the carotid and innominate arteries that supply blood to the brain. Accumulation of the plaques limit the flow of blood and nutrients to the brain, leading to diminished oxygen supply, increased oxidative stress and cell death. All these have been implicated in Alzheimer's disease (AD). Alzheimer's disease, a chronic, progressive, age related neurodegenerative disorder is...
Show moreAtherosclerosis is a cardiovascular disease where plaques made up of lipids in the form of cholesterol ester build up in the carotid and innominate arteries that supply blood to the brain. Accumulation of the plaques limit the flow of blood and nutrients to the brain, leading to diminished oxygen supply, increased oxidative stress and cell death. All these have been implicated in Alzheimer's disease (AD). Alzheimer's disease, a chronic, progressive, age related neurodegenerative disorder is the most common form of dementia in the elderly accounting for 60-80% of the cases. Clinically, Alzheimer's disease is characterized by loss of memory, damage of brain tissues, and neuronal and synaptic loss. Pathologically, it is delineated by accumulation of amyloid beta and tau proteins forming senile plaques and neurofibrillary tangles respectively. Apolipoprotein E (ApoE) polymorphism, increased oxidative stress and products of lipid peroxidation are associated with atherosclerosis and Alzheimer's disease. ApoE is a glycosylated protein that mediates plasma lipoprotein metabolism. ApoE isoforms have differential effect on amyloid beta aggregation and clearance, thus playing an important role in Alzheimer's pathology. Serum paraoxonase 1 (PON1) is a lipoprotein associated antioxidant enzyme that prevents lipid peroxidation. S100B protein is a plasma biomarker, altered expression of which has been implied in AD. We propose the hypothesis that combined deficiencies in apolipoprotein E and antioxidant defense (established by the lack of PON1), together with dyslipidemia and development of carotid atherosclerosis in aging mice would reflect Alzheimer's pathology. The brains of young and old ApoE-PON1 double knockout (DKO) mice and control C57BL/6J mice were harvested. Atherosclerotic lesions were quantified by Image J. RNA was isolated, cDNA was synthesized and quantitative RT-PCR was performed to detect mRNA levels of S100B. Blood levels of S100B protein was measured by ELISA. Brain tissues were stained with Hematoxylin and Eosin stain and 4G8 immunostain to detect histopathological changes. The blood brain barrier (BBB) is altered in AD resulting in increased permeability and vascular dysfunction. The vascular permeability of BBB was analyzed by Evans Blue Dye (EBD) assay. The results showed that the older DKO mice had severe carotid atherosclerosis, increased levels of serum S100B protein and elevated mRNA levels of S100B. Histological examination showed the presence of characteristic hallmarks of AD. The leakage of EBD into brain parenchyma indicated disruption of BBB. The results suggest that diminished blood flow and nutrient supply to the brain due to atherosclerosis and increased oxidative stress might contribute to Alzheimer's pathology. We suggest that older ApoE-PON1 DKO mice may serve as a model of Alzheimer's disease and prevention of atherosclerosis might promote regression of Alzheimer's disease.
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Date Issued: 2016
Identifier: CFE0006483, ucf:51407
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006483

Title: Role of KLF8-CXCR4 signaling in Breast Cancer Metastasis.
Creator: Mukherjee, Debarati, Zhao, Jihe, Khaled, Annette, Altomare, Deborah, Siddiqi, Shadab, University of Central Florida
Abstract / Description: Kr(&)#252;ppel-like factor 8 (KLF8) has been strongly implicated in breast cancer metastasis. However, the underlying mechanisms remain largely unknown. In this study we report a novel signaling from KLF8 to C-X-C cytokine receptor type 4 (CXCR4) in breast cancer. Overexpression of KLF8 in MCF-10A cells induced CXCR4 expression at both mRNA and protein levels. This induction was well correlated with increased Boyden chamber migration, matrigel invasion and transendothelial migration (TEM) of...
Show moreKr(&)#252;ppel-like factor 8 (KLF8) has been strongly implicated in breast cancer metastasis. However, the underlying mechanisms remain largely unknown. In this study we report a novel signaling from KLF8 to C-X-C cytokine receptor type 4 (CXCR4) in breast cancer. Overexpression of KLF8 in MCF-10A cells induced CXCR4 expression at both mRNA and protein levels. This induction was well correlated with increased Boyden chamber migration, matrigel invasion and transendothelial migration (TEM) of the cells towards the ligand CXCL12. On the other hand, knockdown of KLF8 in MDA-MB-231 cells reduced CXCR4 expression associated with decreased cell migration, invasion and TEM towards CXCL12. Histological and database mining analyses of independent cohorts of patient tissue microarrays revealed a correlation of aberrant co-elevation of KLF8 and CXCR4 with metastatic potential. Promoter analysis indicated that KLF8 directly binds and activates the human CXCR4 gene promoter. Furthermore, CXCR4-CXCL12 engagement downstream of KLF8 leads to the feed-forward activation of FAK. Interestingly, KLF8 expression, through CXCR4 engagement, triggered the formation of filopodium-like protrusions (FLP) and thereby enhanced the proliferation rate of breast cancer cells in 3D Matrigel-on-Top culture, under prolonged treatment with CXCL12. This indicates that KLF8 plays a major role in promoting aggressive colonization of tumor cells in a CXCL12-enriched foreign tissue microenvironment, thereby aiding in secondary macrometastasis formation. Xenograft studies showed that overexpression of CXCR4, but not a dominant-negative mutant of it, in the MDA-MB-231 cells prevented the invasive growth of primary tumor and lung metastasis from inhibition by knockdown of KLF8. Apart from lung, KLF8 overexpression also induced spontaneous secondary metastasis to other CXCL12-rich organs through CXCR4 signaling. These results collectively suggest a critical role for KLF8 and the CXCR4-CXCL12 pathway in promoting breast cancer metastasis and shed new light on potentially more effective anti-cancer strategies.
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Date Issued: 2016
Identifier: CFE0006149, ucf:51127
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006149

Title: The CT20 peptide as an agent for cancer treatment.
Creator: Bassiouni, Rania, Khaled, Annette, Altomare, Deborah, Zhao, Jihe, Estevez, Alvaro, University of Central Florida
Abstract / Description: Due to cancer recurrence and the development of drug resistance, metastatic breast cancer is a leading cause of death in women. In the search for a new therapeutic to treat metastatic disease, we discovered CT20p, an amphipathic peptide based on the C-terminus of Bax. Due to inherent properties of its sequence and similarity to antimicrobial peptides, CT20p is a promising cytotoxic agent whose activity is distinct from the parent protein (e.g. does not cause apoptosis). CT20p is not membrane...
Show moreDue to cancer recurrence and the development of drug resistance, metastatic breast cancer is a leading cause of death in women. In the search for a new therapeutic to treat metastatic disease, we discovered CT20p, an amphipathic peptide based on the C-terminus of Bax. Due to inherent properties of its sequence and similarity to antimicrobial peptides, CT20p is a promising cytotoxic agent whose activity is distinct from the parent protein (e.g. does not cause apoptosis). CT20p is not membrane permeable but can be introduced to cells using polymeric nanoparticles, a method that promotes efficient delivery of the peptide into the intracellular environment.We demonstrated that CT20p was cytotoxic using triple negative breast cancer (TNBC) cell lines, primary breast tumor tissue, and breast tumor murine xenografts. Importantly, normal breast epithelial cells and normal primary breast cells were resistant to the lethal effects of the peptide. Examination of multiple cellular processes showed that CT20p causes cell death by promoting cytoskeletal disruption, cell detachment, and loss of substrate-mediated survival signals.In order to identify the intracellular target of CT20p, we performed pull-down experiments using a biotinylated peptide and found that CT20p binds directly to a type II chaperonin called chaperonin containing T-complex (CCT), which is essential for the folding of actin and tubulin into their native forms. The resulting effect of CT20p upon the cytoskeleton of cancer cells is disruption of vital cellular processes such as migration and adhesion. CCT gene expression and protein levels were examined across several breast cancer cell lines, and we found that susceptibility to CT20p correlated with higher CCT levels. Using human cancer tissue microarrays, we determined that CCT was present in significantly higher amounts in tumor tissues compared to normal tissues and that expression often increased with advanced cancer stage. These results indicate that CCT is a promising therapeutic target for the treatment of metastatic breast cancer and suggest that the use of cancer-targeted nanoparticles loaded with CT20p is a novel and effective therapeutic strategy for cancers, such as TNBC, that recur and are refractory to current treatments.
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Date Issued: 2015
Identifier: CFE0006207, ucf:51095
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006207

Title: Bone Morphogenetic Protein-7 Attenuates Inflammation and Apoptosis and Improves Cardiac Function in Diabetes.
Creator: Urbina, Princess, Singla, Dinender, Naser, Saleh, Zhao, Jihe, University of Central Florida
Abstract / Description: Bone Morphogenetic Protein-7 (BMP-7) belongs to the transforming growth factor-? (TGF?) family of cytokines has is known to have potent anti-inflammatory properties. It has been used in patients to treat osteoporosis clinically and has been reported to treat diabetic nephropathy in murine models. Moreover, studies show that inflammation is up-regulated in patients with pre-diabetes (PD). We, therefore, hypothesize that the administration of BMP-7 will attenuate inflammation in the heart of...
Show moreBone Morphogenetic Protein-7 (BMP-7) belongs to the transforming growth factor-? (TGF?) family of cytokines has is known to have potent anti-inflammatory properties. It has been used in patients to treat osteoporosis clinically and has been reported to treat diabetic nephropathy in murine models. Moreover, studies show that inflammation is up-regulated in patients with pre-diabetes (PD). We, therefore, hypothesize that the administration of BMP-7 will attenuate inflammation in the heart of Streptozotocin (STZ)-induced PD mice. In this study, we divided C57Bl/6 mice into three groups: CONTROL, PD, and PD+BMP-7. CONTROL mice received intraperitoneal (i.p.) injections of Sodium Citrate Buffer while PD and PD+BMP-7 groups received i.p. injections of Streptozotocin (STZ) for two days. In addition, PD+BMP-7 mice received intravenous injections (i.v.) of BMP-7 (200(&)#181;g/kg) on the last day of STZ injection and for the following two days. Animals were sacrificed 21 days post last injection and examined for levels of oxidative stress, inflammatory immune response, apoptosis, fibrosis and cardiac function. Our results indicate significant glucose intolerance in PD mice (p(<)0.05), which was attenuated in the PD+BMP-7 group (p(<)0.05). We also observed increased oxidative stress (p(<)0.001) and secretion of pro-inflammatory cytokines (p(<)0.05), interleukin-6 (IL-6) and tumor necrosis factor-? (TNF-?), in PD mice as compared with the controls. PD+BMP-7 mice revealed significant up-regulation of M2 macrophages (p(<)0.05) and secretion of anti-inflammatory cytokines (p(<)0.05), interleukin-10 (IL-10) and interleukin-1RA (IL-1RA), as compared to PD mice. This was observed with a concomitant down-regulation of pro-inflammatory cytokines, IL-6 and TNF-?, as compared to the PD group. Moreover, we observed significantly increased cardiac apoptosis and fibrosis in PD mice (p(<)0.001) as compared to the control group. These observations, however, were down-regulated upon treatment with BMP-7. Lastly, analysis of echocardiograms revealed significantly depressed cardiac function in PD mice as compared with controls, while the PD+BMP-7 group presented improved cardiac function compared to PD mice. In conclusion, our data suggest that treatment with BMP-7 is effective in alleviating cardiac inflammation, inhibiting apoptosis, blunting cardiac remodeling and improving cardiac function in the hearts of STZ-induced PD mice. This reveals the potential of BMP-7 as a therapy in PD patients who present an increased inflammatory immune response.
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Date Issued: 2013
Identifier: CFE0004765, ucf:49799
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004765

Title: The Role of LIM Kinase 1 and its Substrates in Cell Cycle Progression.
Creator: Ritchey, Lisa, Chakrabarti, Ratna, Zervos, Antonis, Zhao, Jihe, Vonkalm, Laurence, University of Central Florida
Abstract / Description: LIM Kinase 1 (LIMK1), a modulator of actin and microtubule dynamics, has been shown to be involved in cell cycle progression. In this study we examine the role of LIMK1 in G1 phase and mitosis. We found ectopic expression of LIMK1 resulted in altered expression of p27Kip1, the G1 phase Cyclin D1/Cdk4 inhibitor. Overexpression of LIMK1 resulted in lower levels of p27Kip1 and p27Kip1-pY88 (inactive p27Kip1). Knockdown of LIMK1 resulted in elevated levels of p27Kip1 and p27Kip1-pY88. Together,...
Show moreLIM Kinase 1 (LIMK1), a modulator of actin and microtubule dynamics, has been shown to be involved in cell cycle progression. In this study we examine the role of LIMK1 in G1 phase and mitosis. We found ectopic expression of LIMK1 resulted in altered expression of p27Kip1, the G1 phase Cyclin D1/Cdk4 inhibitor. Overexpression of LIMK1 resulted in lower levels of p27Kip1 and p27Kip1-pY88 (inactive p27Kip1). Knockdown of LIMK1 resulted in elevated levels of p27Kip1 and p27Kip1-pY88. Together, these results suggest LIMK1 regulates progression of G1 phase through modulation of p27Kip1 expression.LIMK1 is involved in the mitotic process through inactivating phosphorylation of Cofilin. Aurora kinase A (Aur-A), a mitotic kinase, regulates initiation of mitosis through centrosome separation and proper assembly of bipolar spindles. Phosphorylated LIMK1 is recruited to the centrosomes during early prophase, where it colocalizes with ?-tubulin. Here, we report a novel functional cooperativity between Aur-A and LIMK1 through mutual phosphorylation. LIMK1 is recruited to the centrosomes during early prophase and then to the spindle poles, where it colocalizes with Aur-A. Aur-A physically associates with LIMK1 and activates it through phosphorylation, which is important for its centrosomal and spindle pole localization. Aur-A also acts as a substrate of LIMK1, and the function of LIMK1 is important for its specific localization and regulation of spindle morphology. Taken together, the novel molecular interaction between these two kinases and their regulatory roles on one other's function may provide new insight on the role of Aur-A in manipulation of actin and microtubular structures during spindle formation.The substrates of LIMK1, Aur-A and Cofilin, are also involved in the mitotic process. Aur-A kinase regulates early mitotic events through phosphorylation and activation of a variety of proteins. Specifically, Aur-A is involved in centrosomal separation and formation of mitotic spindles in early prophase. The effect of Aur-A on mitotic spindles is mediated by modulation of microtubule dynamics and association with microtubule binding proteins. In this study we show that Aur-A exerts its effects on spindle organization through regulation of the actin cytoskeleton. Aur-A phosphorylates Cofilin at multiple sites including S3 resulting in inactivation of its actin depolymerizing function. Aur-A interacts with Cofilin in early mitotic phases and regulates its phosphorylation status. Cofilin phosphorylation follows a dynamic pattern during progression of prophase to metaphase. Inhibition of Aur-A activity altered subcellular localization of Cofilin and induced a delay in the progression of prophase to metaphase. Aur-A inhibitor also disturbed the pattern of Cofilin phosphorylation, which correlated with the mitotic delay. Our results establish a novel function of Aur-A in the early mitotic stage through regulation of actin cytoskeleton reorganization.?
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Date Issued: 2014
Identifier: CFE0005701, ucf:50156
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005701

Title: IDENTIFICATION OF EPITHELIAL STROMAL INTERACTION 1 AND EPIDERMAL GROWTH FACTOR RECEPTOR AS NOVEL KR(&)#220;PPEL-LIKE FACTOR 8 TARGETS IN PROMOTING BREAST CANCER PROGRESSION.
Creator: Li, Tianshu, Zhao, Jihe, Khaled, Annette, Altomare, Deborah, Lambert, Stephen, University of Central Florida
Abstract / Description: Breast cancer is the major cause of cancer death among women worldwide. Understanding the mechanisms underlying breast cancer progression remains urgent for developing effective treatment strategies to eliminate breast cancer mortality. Our recent studies have demonstrated that Kr(&)#252;ppel-like transcriptional factor 8 (KLF8) plays a critical role for breast cancer progression. Other studies have shown that Epithelial stromal interaction 1 (EPSTI1), a recently identified stromal fibroblast...
Show moreBreast cancer is the major cause of cancer death among women worldwide. Understanding the mechanisms underlying breast cancer progression remains urgent for developing effective treatment strategies to eliminate breast cancer mortality. Our recent studies have demonstrated that Kr(&)#252;ppel-like transcriptional factor 8 (KLF8) plays a critical role for breast cancer progression. Other studies have shown that Epithelial stromal interaction 1 (EPSTI1), a recently identified stromal fibroblast-induced gene in non-invasive breast cancer cells and epidermal growth factor receptor (EGFR) are highly overexpressed in aggressively invasive breast carcinomas including triple negative breast cancers. In this thesis project, we demonstrate high co-overexpression of KLF8 with EPSTI1 as well as EGFR in invasive breast cancer cells and patient tumors. We also show that KLF8 upregulates the expression of EPSTI1 by directly binding and activating the EPSTI1 gene promoter, and KLF8 upregulates the expression of EGFR not only by directly activating the EGFR gene promoter but also by preventing EGFR translation from microRNA141-dependent inhibition. Genetic, signaling and animal cancer model analyses indicate that downstream of KLF8, EPSTI1 promotes the tumor invasion and metastasis by activating NF-?B through binding valosin containing protein (VCP) and subsequent degradation of I?B?, whereas EGFR promotes tumor growth and metastasis via activation of ERK. Taken together, these data identify EPSTI1 and EGFR as novel KLF8 targets in breast cancer and suggest that KLF8 may be targeted for new effective treatment of breast cancer.
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Date Issued: 2013
Identifier: CFE0005366, ucf:50474
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005366

Title: A novel link between Akt1 and Twist1 in ovarian tumor cell motility and invasiveness.
Creator: Shah, Nirav, Altomare, Deborah, Zhao, Jihe, Khaled, Annette, University of Central Florida
Abstract / Description: Ovarian cancer results in more deaths per year than any other cancer of the female reproductive system. The low survival rate is partly due to the lack of early detection and the susceptibility to relapse. The AKT serine threonine kinase plays a pivotal role in hallmark cellular processes for the progression of ovarian cancer, including tumor cell growth and migration. Therapeutic targeting of pan-AKT has been problematic, in part due to feedback mechanisms and crosstalk with other pathways....
Show moreOvarian cancer results in more deaths per year than any other cancer of the female reproductive system. The low survival rate is partly due to the lack of early detection and the susceptibility to relapse. The AKT serine threonine kinase plays a pivotal role in hallmark cellular processes for the progression of ovarian cancer, including tumor cell growth and migration. Therapeutic targeting of pan-AKT has been problematic, in part due to feedback mechanisms and crosstalk with other pathways. The hypothesis for this study is that AKT 1, -2 and -3 isoforms may have different roles and regulate cell processes in uniquely varied ways. A transgenic mouse model that expresses the SV40 T-antigen viral oncogene and is known to have dramatically increased susceptibility to ovarian cancer was utilized, and it had genetic inactivation of either AKT1 or AKT2 through targeted deletion of the individual genes because these isoforms have been implicated in this cancer. Primary ovarian tumor cell cultures were established and found to exhibit different morphology, proliferation and migration that may indicate a different role for the AKT1 and AKT2 isoforms in these contexts. Ovarian tumor cells with absence of AKT1 predominantly exhibited reduced cell migration when compared to cells with retention of AKT1 and absence of AKT2. Since AKT is known to be important for epithelial-mesenchymal transition (EMT), a process potentially associated with tumor cell metastasis, the expression of transcription factors implicated in EMT was assessed by real-time array analysis in ovarian tumor cells knocked-out for either AKT1 or AKT2. Twist1, one of the major players in EMT, was not detectable in the cells missing the AKT1 isoform. Results indicate an association of Twist1 with AKT1 in EMT and migration of ovarian tumors cells. This finding is significant because AKT2 has been implicated as the major player of cell migration in human breast cancer cells. Collectively, these findings support a tissue specific role of the AKT isoforms, and may provide insights regarding the most useful cell context in order to target components of the AKT signaling pathway indirectly affecting EMT in order to prevent tumor progression in patients with ovarian and perhaps other types of cancers.
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Date Issued: 2012
Identifier: CFE0004630, ucf:49916
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004630

Title: Regulation of Extra-Pituitary Prolactin in Monocytes and Macrophages.
Creator: Barrett, Richard, Parthasarathy, Sampath, McKinstry, Karl, Masternak, Michal, Zhao, Jihe, University of Central Florida
Abstract / Description: Recently it has been shown that leukocytes are capable of producing prolactin (PRL). Evidence of extra-pituitary PRL (ePRL) production is so far been limited to primates and is not shared across other mammal species such as mice and rats. While ePRL is characterized as an identical protein to traditional pituitary PRL, it is controlled under an alternative promoter and is thus regulated differently from pituitary PRL. Little is known about what regulates ePRL or its direct role in human...
Show moreRecently it has been shown that leukocytes are capable of producing prolactin (PRL). Evidence of extra-pituitary PRL (ePRL) production is so far been limited to primates and is not shared across other mammal species such as mice and rats. While ePRL is characterized as an identical protein to traditional pituitary PRL, it is controlled under an alternative promoter and is thus regulated differently from pituitary PRL. Little is known about what regulates ePRL or its direct role in human physiology, but given that PRL has well over 300 described functions, it is likely that the autocrine and paracrine effects of this hormone could have far reaching implications in overall physiology. This work takes some of the first steps in understanding how leukocyte ePRL is regulated. Our results show that, adrenergic hormones are one key stimulus in ePRL expression in monocytes/macrophages. This is particularly intriguing considering the opposing role of these two signals in settings such as adipose tissue where adipose tissue macrophages are constantly exposed to pro-lipolytic adrenergic hormones that would in turn stimulate production of an anti-lipolytic hormone, PRL. Further, our work shows that the inflammatory phenotype of the leukocytes influences basal expression of PRL and overall ePRL expression increases significantly as monocytes differentiate into macrophages, as is a common occurrence in adipose tissue. The final portion of our work shows how monocytes/macrophages also respond to preadipocytes directly. These stem cell precursors to mature adipose cells release an unknown factor that stimulates ePRL production in monocytes/macrophages. Analysis of our gene array shows many of the genes stimulated by adipose stem cells alongside PRL are important genes in tissue regeneration and remodeling, a possible role that fits well with known effects of PRL. Understanding such primate specific interactions between the immune system and major metabolic tissues such as adipose fills vital gaps in knowledge that may explain why so many treatments fail when transitioning from mouse models to humans.
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Date Issued: 2018
Identifier: CFE0007309, ucf:52164
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007309

Title: Novel Cytokine Signaling and Molecular Therapeutic Strategy in Pancreatic Cancer.
Creator: Gitto, Sarah, Altomare, Deborah, Khaled, Annette, Zhao, Jihe, Copik, Alicja, Masternak, Michal, University of Central Florida
Abstract / Description: Pancreatic ductal adenocarcinoma (PDAC) is highly chemo-resistant and has a five year survival rate of (
Show morePancreatic ductal adenocarcinoma (PDAC) is highly chemo-resistant and has a five year survival rate of (<)8%. Risk factors of pancreatic cancer, such as chronic pancreatitis, help to elicit a pro-tumor immune response, and highly fibrotic environment that promotes tumorigenesis. To study how chronic pancreatitis promotes cancer initiation, traditional KRasG12D mice and double mutant Akt1Myr/KrasG12D mice were used to model microenvironment changes. Akt1Myr/KrasG12D mice were more susceptible to chronic tissue damage, accelerated tumor development and metastatic disease. These mice exhibited histological changes consistent with immune cell privilege, where M2 macrophages and non-cytotoxic eosinophils were co-localized with fibrotic regions. IL-5 expression was up regulated in pancreatic cells undergoing acinar to ductal metaplasia and then diminished in advanced lesions. Tumor cells treated with IL-5 exhibit increased migration and activation through STAT5 signaling. Collectively, the results suggest that eosinophils, which are responsive to IL-5, are key mediators in the pancreatic environment subjected to chronic inflammation and injury.Current therapeutics fall short in increasing patient survival. There remains an urgent need for innovative treatments and thus we tested difluoromethylornithine (DFMO) in combination with a novel polyamine transport inhibitor, Trimer44NMe, against Gemcitabine-resistant PDAC cells. Prior clinical failures when targeting polyamine biosynthesis with DFMO monotherapy may be due to tumor escape via an undefined polyamine transport system. In pancreatic tumor cells DFMO alone and with Trimer44NMe significantly reduced PDAC cell viability by inducing apoptosis or cell cycle arrest. In vivo orthotopic PDAC growth with DFMO treatment resulted in decreased c-Myc expression, a readout of polyamine pathway dysfunction. Moreover, dual inhibition significantly prolonged survival of tumor-bearing mice, and increased M1 macrophage infiltration and reduced FoxP3 expression. Collectively, these studies demonstrate that targeting polyamine pathways in PDAC is a promising immunomodulating therapy that increases survival.
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Date Issued: 2017
Identifier: CFE0007283, ucf:52168
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007283

Title: A major double strand repair pathway and cancer-associated circulating proteins are effecters of epigenetic revision.
Creator: Allen, Brittany, Masternak, Michal, Khaled, Annette, Zhao, Jihe, Muller, Mark, Siddiqi, Shadab, University of Central Florida
Abstract / Description: DNA methylation is a vital epigenetic process that acts as a major control mechanism for gene expression. In addition to its essential role in many normal cellular processes, it is also implicated in a wide variety of disease states and processes including cancer. Along with genetic mutations, aberrant DNA methylation patterns, specifically the inappropriate DNA methylation or demethylation of CpG residues, may activate oncogenes or suppress tumor suppressor genes, respectively. These changes...
Show moreDNA methylation is a vital epigenetic process that acts as a major control mechanism for gene expression. In addition to its essential role in many normal cellular processes, it is also implicated in a wide variety of disease states and processes including cancer. Along with genetic mutations, aberrant DNA methylation patterns, specifically the inappropriate DNA methylation or demethylation of CpG residues, may activate oncogenes or suppress tumor suppressor genes, respectively. These changes can generate or facilitate the progression of tumorigenesis and tend to accumulate throughout the development of cancer. Although they play such a major role in cancer and in other diseases, it remains unclear what causes these epigenetic revisions to occur. This dissertation will focus on uncovering mechanisms that are sources of epigenetic revision, specifically as they relate to cancer. Due to rapid cell division and increased DNA damage, cells are increasingly dependent on DNA repair as they continue on a path of tumorigenic progression. We hypothesize that DNA repair, specifically the repair of DNA double strand breaks (DSB) by Non-Homologous End Joining (NHEJ) may play a role in inappropriate epigenetic revision. Using a GFP reporter system inserted into the genome of HeLa cells, we are able to induce targeted DNA damage that enables the cells, after successfully undergoing NHEJ repair, to express WT GFP. These GFP+ cells were segregated into two expression classes, one with robust expression (Bright) and the other with reduced expression (Dim). Using a DNA hypomethylating drug (AzadC) we were able to demonstrate that the different GFP expression levels was due to differential methylation statuses of CpGs in regions on either side of the break site. Deep sequencing analysis of this area in sorted Bright and Dim populations revealed a collection of different epi-alleles that display patterns of DNA methylation following repair by NHEJ. These patterns differ between Bright and Dim cells which are hypo- and hypermethylated, respectively, and between the post-repair populations and the original, uncut cells. These data suggest that NHEJ repair facilitates a rewrite of the methylation landscape in repaired genes, elucidating one potential source for the altered methylation patterns seen in cancer cells.The Dim cells generated during this study are known to have a hypermethylated GFP gene that is correlated with reduced expression, allowing it to be used as a screening tool for hypomethylating agents. We used this tool to screen the blood serum of patients with head and neck squamous cell carcinoma (HNSCC). We found that the serum from HNSCC patients, but not from healthy individuals, contains some factor that causes hypomethylation in exposed cells. Further, we were able to identify this factor as a protein capable of effecting changes in DNA methylation, gene expression, and miRNA levels in the treated Dim cells. The novel concept presented in this study has immense implications on the study of cancer progression as it evidences circulating proteins, presumably released by cancer cells, which are able to effect gene expression in cells that are distal to the location of the cancer. Further, the fact that these proteins are in circulation makes them a potential target for use in diagnostics. Changes in DNA methylation play a major role in the development of cancer and understanding the mechanisms by which this occurs could provide new therapeutic targets for preventing this process from contributing to tumorigenesis. This dissertation presents potential sources of epigenetic revision in cancer and thus provides answers to a major question that has yet to be answered in the area of cancer research.
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Date Issued: 2017
Identifier: CFE0006555, ucf:51333
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006555

KLF8 (3)	+ -
breast cancer (3)	+ -
Atherosclerosis (2)	+ -
Pancreatic Cancer (2)	+ -
ovarian cancer (2)	+ -

AKT (1)	+ -
Akt1 (1)	+ -
Alzheimer's disease (1)	+ -
Amyloid beta plaques (1)	+ -
Angiogenesis (1)	+ -
Anti cancer compounds (1)	+ -
Apoptosis (1)	+ -
BMP-7 (1)	+ -
BMP7 (1)	+ -
Blood Brain barrier (1)	+ -
CXCL12 (1)	+ -
CXCR4 (1)	+ -
Cancer (1)	+ -
Cardiomyopathy (1)	+ -
Cerium Oxide Nanoparticles (1)	+ -
DNA binding proteins (1)	+ -
DNA methylation (1)	+ -
DNA repair (1)	+ -
Diabetes (1)	+ -
Diabetes Mellitus (1)	+ -
Diabetic Cardiomyopathy (1)	+ -
EGFR (1)	+ -
EMT (1)	+ -
EPSTI1 (1)	+ -
Eosinophils (1)	+ -

University of Central Florida (17)	+ -
Zhao, Jihe (17)	+ -
Altomare, Deborah (8)	+ -
Khaled, Annette (8)	+ -
Masternak, Michal (5)	+ -

Parthasarathy, Sampath (3)	+ -
Siddiqi, Shadab (3)	+ -
Chakrabarti, Ratna (2)	+ -
Estevez, Alvaro (2)	+ -
Muller, Mark (2)	+ -
Singla, Dinender (2)	+ -
Albury, Toya (1)	+ -
Allen, Brittany (1)	+ -
Baker, Cheryl (1)	+ -
Barrett, Richard (1)	+ -
Bassiouni, Rania (1)	+ -
Chakrabarti, Debopam (1)	+ -
Copik, Alicja (1)	+ -
Cyril Sagayaraj, Vidusha (1)	+ -
Garner, Kaley (1)	+ -
Gitto, Sarah (1)	+ -
Hasan, Md Faqrul (1)	+ -
Kim, Yoon-Seong (1)	+ -
Lahiri, Satadru (1)	+ -
Lambert, Stephen (1)	+ -
Li, Tianshu (1)	+ -
McKinstry, Karl (1)	+ -
Mitra, Connie (1)	+ -
Mukherjee, Debarati (1)	+ -
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