Master of Science, The Ohio State University, 2018, Biomedical Engineering

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are lung disorders characterized by increased permeability of the alveolar barrier, resulting in fluid buildup and hypoxia. Patients with ALI or ARDS often require mechanical ventilation to displace occluded fluid and restore blood oxygenation. However, mechanical ventilation exposes alveolar and small airway epithelial cells to abnormal mechanical forces, which can exacerbate lung inflammation and injury, known as ventilator-induced lung injury (VILI). MicroRNAs, short RNAs with post-translational regulatory roles in gene expression, have emerged as promising therapeutic targets to protect against VILI. MicroRNAs 146a and 155 have been implicated in innate immunity, and shown to modulate inflammatory response during simulated lung injury . Delivery of microRNA cargos is critical for clinical translation into future VILI therapy. Endogenous extracellular vesicles (EVs) have emerged as potential drug carriers capable of delivering microRNAs of interest. To study EV-mediated delivery of microRNA-146a, A549 epithelial cell or differentiated THP-1 macrophage monocultures were incubated with either EVs containing pre-miR-146a or scramble gene, or reduced-serum media for 24 hours. MicroRNA expression levels were evaluated via qRT-PCR. EVs delivered pre-miR-146a into A549 and THP-1 cell cocultures, then oscillatory pressure (20 cmH2O, 0.2Hz) was applied for 16 hours. Secretion of interleukin (IL)-1ß, IL-6, and IL-8 was quantified via ELISA. MicroRNA-146a was overexpressed in monocultures of A549 and PMA-differentiated THP-1 cells. In cocultures with applied oscillatory pressure, dampening of IL-1ß and IL-6 secretion was inconclusive. Secretion of IL-8 significantly increased between pressure and no-pressure groups, with EVs potentially increasing pro-inflammatory response. Relative fold-change in cytokine secretion between treatment groups did not change. Overexpression of microRNA-146a (open full item for complete abstract)

Doctor of Philosophy (PhD), Wright State University, 2025, Environmental Sciences PhD

Lung surfactant is a complex mixture of phospholipids and proteins lining the alveoli. It is critical in maintaining lung function by reducing surface tension during respiration. However, exposure to environmental contaminants such as diesel exhaust particulate (DEP), a major component of air pollution, has been linked to respiratory illnesses. This dissertation research investigated the impact of DEP exposure on lung surfactant composition and efficacy. The central research question guiding this study was: How does exposure to DEP and secretory IgA alter the composition and efficacy of lung surfactant? The hypothesis tested was that DEP exposure disrupts the delicate balance of phospholipids and proteins within lung surfactant, leading to impaired surface tension regulation, protein interaction, and altered lung surfactant function. This study employed advanced analytical techniques to characterize changes in surfactant composition after DEP exposure. The data showed that adding DEP and secretory IgA changed the species distribution within each phosphatidylcholine group. Protein interactions were observed between SP-A and SP-D, and lung surfactant function was altered with exposure to DEP.

Master of Science (MS), Wright State University, 2023, Biochemistry and Molecular Biology

Extracellular signal related kinase 3 (ERK3) is one of the atypical mitogen activated protein kinases (MAPK). It is expressed ubiquitously and plays a role in a variety of cellular processes, including cell growth and differentiation. ERK3's role in promoting migration and invasion in various cancers has been well established. ERK3 is upregulated in non-small cell lung cancers (NSCLCs) and has been shown to promote NSCLC tumor growth and progression. However, the regulation of ERK3 in lung cancers remains largely unclear. A recent study indicates that ERK3 phosphorylation at S189, an indicator of ERK3 activity, is upregulated by KRAS in NSCLCs. KRAS is one of the most commonly mutated oncogenes in lung cancers. To study the KRAS dependent regulation of ERK3, knockdown of KRAS was performed and it resulted in a remarkable reduction in ERK3 phosphorylation as well as total ERK3 protein level confirming the regulation of ERK3 by KRAS. Upon knockdown of KRAS a significant reduction of ERK3 mRNA level was observed indicating that KRAS regulates ERK3 at transcriptional level. Further, we found that the regulation of ERK3 by KRAS may be through the transcription factor c-Jun, that is well-known to be activated by KRAS signalling. Our data indicates that c-Jun positively regulates ERK3 transcription in LUAD cell lines. Further, we have found that KRAS upregulates c-Jun activating phosphorylations in LUAD cells, suggesting that KRAS regulates ERK3 through c-Jun. Given the discrepancy regarding the role of ERK3 in NSCLC cell growth reported in previous studies, we have thoroughly investigated the role of ERK3 in cell growth by stable knockdown of ERK3 using shRNA targeting different regions of ERK3 mRNA, as well as by using ERK3 inhibitors in a variety of NSCLS cell lines. While knockdown of ERK3 via targeting the coding region did not affect cell proliferation, targeting the 3'UTR of ERK3 or treatment with ERK3 inhibitors reduced the proliferation of LUAD cells.

Doctor of Philosophy, The Ohio State University, 2021, Biomedical Engineering

Lung cancer is leading cause of cancer-related deaths in the United States with 5-year survival rate of 18.6%. This is due to late detection of lung cancer and problems in screening for lung cancer. Indeterminate pulmonary nodules (IPNs) are pulmonary nodules size between 7-20mm diameter solid nodules. 90% of IPNs are incidentally found and they are hard to diagnosis due to their small size and current diagnosis methods such as CT, PET scans and biopsy involve high exposure to radiation or invasive and could lead to complications. The majority of lung cancer patients have non-small cell lung cancer (NSCLC) and 64% of these patients exhibit driver mutations such as epithelial growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK) and Ras mutations. These patients have shown to have improved survival rate if they are treated with targeted therapies directed against the driver mutations. Although these patients initially show strong response to targeted therapies, most patients develop resistance to these targeted treatments through secondary point mutation and epithelial to mesenchymal transition (EMT). The lung is a dynamic organ where alveolar epithelial cells are normally exposed to significant mechanical forces (i.e. ~8% cyclic strain, transmural pressure and shear stress) while primary lung tumor cells experience a 40-fold decrease in these mechanical forces/strain. Although biomechanical factors in the tumor microenvironment have been shown to be a significant driver of cancer progression, there is limited information about how biophysical forces alters drug sensitivity in lung adenocarcinoma cells. Based on the known importance of mechanical forces/strain on lung injury and repair and the significant difference in cyclic strain applied to normal and cancer cells in the lung, we hypothesized that cyclic mechanical strain would activate important oncogenic pathways and alter drug sensitivity. Although local mechanical properties of the lung tumor may (open full item for complete abstract)

PhD, University of Cincinnati, 2025, Medicine: Immunology

As the field of ILC biology develops, it is becoming increasingly appreciated that these cells play critical roles in mediating immune responses at mucosal surfaces. This is especially true in the neonatal lung, where ILC responses promote skewing towards Type 2 immunity, altering susceptibility to infections and increasing the risk of allergic lung disease. Despite this, the mechanisms that drive their ILC development, maintenance, and functions within this environment remain poorly understood. Our studies address this gap in knowledge by interrogating ILCs through single cell sequencing technologies. Using a murine model of early life dysbiosis, we have generated a dataset of ILC populations from the lungs of neonatal and young adult mice. Our dataset includes ILC2s, ILC3s, NK cells, and a range of both hematopoietic and non-hematopoietic cells from the lung environment that are known to interact with ILCs. Using the non-dysbiotic control animals from our single cell dataset we are able to compare gene expression and chromatin accessibility between neonatal and young adult ILCs to look for unique features that define lung-resident ILCs in neonates. The inclusion of dysbiotic animals allows us to further interrogate the effects of early life antibiotic exposure on these populations.

Master of Sciences, Case Western Reserve University, 2024, Clinical Research

Rationale: Surgical lung biopsy offers the highest histopathologic yield to diagnose ILD, which affects treatment decisions and informs prognosis. It is associated with morbidity and non-negligible mortality. Methods: Single center retrospective study of 231 patients who underwent SLB. Patient characteristics were analyzed to evaluate association with complications measured by hospital LOS. Results: 59 (25%) of our patients had a LOS >2 days in the first 90 post-procedure days. 13 (5.6%) patients had a LOS >6 days, which included 8 (3.4%) exacerbations and 5 (2.2%) deaths. FVC% was independently associated with LOS (OR of 0.98, 95% CI 0.97- 0.99). RVSP was independently associated with LOS > 2 days (OR 1.47, 95% CI (1.01, 2.24)) by standard logistic regression, and 1.51 (1.09, 2.14) with a Bayesian approach. A model to predict LOS > 2 days performed modestly (AUC 0.69) in our training (75%) sample, but poorly (AUC 6.0-6.1) in our testing (25%) sample.

Bachelor of Science (BS), Ohio University, 2022, Biological Sciences

Lung cancer is the second most prevalent cancer in both men and women in the United States, and it currently the leading cause of cancer-related deaths. While there are current standard treatments for lung cancer, these treatments are not effective enough, and can lead to drug resistance, severe side effects, and even recurrence of the cancer and death. It is easy to see that better anticancer therapies are urgently needed. It has been shown that many cancer types, including Non-Small Cell Lung Cancer (NSCLC), which makes up 84% of all lung cancer diagnosis, are addicted to glucose and are sensitive to glucose deprivation, ultimately resulting in cancer cell-death. DRB18 is a small molecule compound developed at Ohio University that has been shown to target and inhibit glucose transporters (GLUTs), which are responsible for the uptake of glucose into cells, particularly cancer cells. DRB18 has been shown to be effective in inhibiting cancer cell growth in vitro (cell culture) and in vivo (nude mice) without noticeable side effects. While this may be a promising anticancer therapy by itself, combining DRB18 with an FDA-approved anticancer drugs Paclitaxel, Trametinib, or Brigatinib maximized the efficacy of the treatment in vitro in NSCLC A549 cells, and combination treatment of DRB18 + Paclitaxel resulted in shrunken A549 xenograft tumors in vivo, without increasing unwanted side effects. This combination therapy has the potential to benefit cancer patients for decades to come.

Doctor of Philosophy, The Ohio State University, 2022, Biomedical Sciences

Small cell lung cancer (SCLC) is an extremely aggressive neuroendocrine tumor, accounting for approximated 13% of all lung cancer cases. SCLC is characterized by rapid growth and early metastasis. Despite marked improvements in the number and efficacy of targeted, therapeutic options and overall survival rates in SCLC have remained nearly unchanged for almost three decades. The lack of significant progress can be attributed to our poor understanding of the biology of SCLC. Although immune checkpoint inhibitors were recently approved as front-line therapies for SCLC, we still need to better understand the mechanisms responsible for the selective vulnerability of some SCLCs to these inhibitors. Recent work utilizing sequencing data and single cell analyses identified four distinct subsets of SCLC, based on the expression levels of the transcription factors ASCL1, NEUROD1, POU2F3 and YAP1. Each subset was found to have its own distinct biology and therapeutic vulnerabilities. However, these subsets appear to be phenotypically unstable, representing snapshots in the gradual evolution of a tumor that exhibits significant plasticity. Tumor evolution, a product of this plasticity, results in the emergence of significant intratumoral heterogeneity which plays an important role in multiple aspects of SCLC development and progression, including cell survival and proliferation, metastasis and angiogenesis. The recent paradigm shifting discoveries in the biology of SCLC are now beginning to inform the design of new therapeutic strategies for the management of this intractable disease. Receptor Tyrosine Kinase-like Orphan Receptor 1 (ROR1) is an oncofetal protein that is emerging as a therapeutic target and is co-expressed with BCL2 in multiple tumor types due to microRNA coregulation. We hypothesize that ROR1-targeted therapy is effective in small cell lung cancer and synergizes with therapeutic BCL2 inhibition. Tissue microarrays (TMAs) and formalin-fixed paraffin-embedded (F (open full item for complete abstract)

Doctor of Philosophy, The Ohio State University, 2019, Biomedical Sciences

LKB1 is the fourth-most frequently mutated gene in lung adenocarcinoma, with loss-of-function observed in up to 30% of all cases (Collisson et al. 2014; Kaufman et al. 2014). Our previous work identified a 16-gene signature for LKB1 loss of function through not just mutation, but deletion and epigenetic silencing, which occurs relatively frequently (Lee et al. 2013; Kaufman et al. 2014). We applied this genetic signature to lung adenocarcinoma samples in the Cancer Genome Atlas (TCGA) and discovered a novel association between LKB1 loss and widespread CpG demethylation. LKB1-loss tumors also expressed significantly less DNA methyl transferase (DNMT1) and show depletion of S-Adenosyl-Methionine (SAM-e), which is the primary substrate for DNMT1 activity. Repetitive element transcriptional start sites are demethylated and sensitivity to azacytidine is lower in LKB1 loss. Mechanistically, demethylated CpGs are enriched for FOXA1/2/3 consensus binding sites, and we further identified that FOXA localization and turnover is dependent upon LKB1 and the downstream kinase SIK. Overall, these findings demonstrate that a large number of lung adenocarcinoma patients have a unique epigenetic profile driven by LKB1 loss which could play a role in lung tumorigenicity and resistance to immunotherapy.

Doctor of Philosophy, Case Western Reserve University, 2018, Molecular Medicine

The sustainable activation of the RAS/MAPK and PI3K/AKT signaling pathways in cancer is promoted by a reduction in the activity of the tumor suppressor protein phosphatase 2A (PP2A). Therefore, a novel therapeutic strategy consists of directly activating PP2A, leading to the simultaneous inhibition of these oncogenic pathways. Our lab has successfully developed first-in-class Small Molecule Activators of PP2A (SMAPs), which induce tumor growth inhibition in vivo. Alterations to the putative drug binding site validate PP2A as the direct target of SMAPs. The putative residues of PP2A-Aa that were interacting with SMAPs K194 E197, and L198 were mutated. H358, a KRAS-driven lung adenocarcinoma cell line, was used to create isogenic cell lines stably overexpressing mutated and wild type PP2A-Aa. SMAP response was investigated in vivo using a xenograft model of H358 isogenic cell lines and it was determined that tumors harboring mutant K194R and L198V PP2A-Aa were resistant to SMAPs treatment. Together, our results suggest that residues K194 and L198 are required for drug binding and subsequent target engagement. On another hand, most lung adenocarcinoma (LUAD) patients acquire resistance to tyrosine kinase inhibitors (TKI) via mechanisms enabling the sustained activation of the MAPK and PI3K oncogenic pathways downstream of the tyrosine kinase EGFR. We hypothesize that activation of PP2A simultaneously inhibits the MAPK and AKT pathways and is a promising therapeutic strategy for TKI-resistant LUAD. TKI-resistant LUAD cell lines were treated with SMAPs. RNAseq kinase enrichment analysis followed by principal component analysis indicated that SMAP treatment induces a gene signature similar to a combination of the selective AKT and MEK inhibitors MK2206 and AZD6244, respectively. The therapeutic potential of PP2A activation in vivo was first evaluated in a transgenic mouse model. SMAP- treated mice showed less diffuse lung cancer and a significant decrease in (open full item for complete abstract)

Master of Science, University of Akron, 2017, Biomedical Engineering

Delivery of therapeutic fluids such as surfactant solutions into lungs is a major strategy to treat various respiratory disorders. Instilled solutions form liquid plugs in lung airways. The plugs propagate downstream in airways by inspired air or forced ventilation, continuously split at airway bifurcations to smaller daughter plugs and simultaneously lose mass from their trailing menisci, and eventually rupture. A uniform distribution of the instilled liquid in lung airways is expected to increase the treatments success. The uniformity of distribution of instilled liquid in the lungs greatly depends on the splitting of liquid plugs between daughter airways, especially in the first few generations of airways from which airways of different lobes of lungs emerge. To mechanistically understand the liquid plug splitting process, we develop a novel bioengineering approach to computationally design three-dimensional bifurcating airway models using morphometric data of human lungs, fabricate seamless physical models using additive manufacturing, and examine effects of geometry of airways, fluid properties, and flow characteristics on liquid plug splitting. We find that the orientation of bifurcating airways has a major effect on the splitting of liquid plugs between daughter airways and discuss the role of various forces including inertia, gravity, and surface tension using several dimensionless groups. This work provides a fundamental understanding toward developing delivery strategies for uniform distribution of therapeutic fluids in the lungs.

Doctor of Philosophy, University of Akron, 2017, Chemistry

Imidazolium salts have received significant attention for their anti-cancer properties. Human cancer cell lines have been treated with hundreds of imidazolium salts and many have shown promise for clinical potential. The leader of this class is YM155, a survivin suppressor that has gone through clinical trials but is not yet approved by the Food and Drug Administration (FDA) for the treatment of cancer. Numerous studies have been compiled to create structure activity relationships addressing what functional groups can help increase anti-proliferative effects and which functional groups produce imidazolium salts with weak anti-cancer properties. The general trend throughout the literature is that lipophilicity increases anti-cancer potential. Unfortunately, little is known about the mechanism of action, cellular target, and specificity of imidazolium salts which are all limiting factors towards progression into clinical applications. Chapter II describes the synthesis and characterization of a series of N,N'-bis(naphthylmethyl) imidazolium salts. These compounds were also tested for their in vitro anti-cancer properties against several non-small cell lung cancer cell lines and found to be highly active. Each compound had low aqueous solubility, but could be solubilized by a cyclodextrin that is FDA approved for drug formulations. In vitro mechanism of action studies were also performed on one compound and suggested the compound induced an apoptotic mode of cell death. Chapter III provides the synthesis and characterization of a related series of compounds with higher aqueous solubility. The major findings included the incorporation of quinolylmethyl moieties, similar to naphthylmethyl substituents, to increase aqueous solubility without drastically lowering anti-cancer activity. It was also determined that the anion plays a significant role in the aqueous solubility of these imidazolium salts. Chapter IV presents the synthesis, characterization, and in vitr (open full item for complete abstract)

Doctor of Philosophy, University of Akron, 2016, Chemistry

Imidazolium salts are unique for their biological activity and application in the field of cancer research. Pharmaceutical research of imidazole-based antitumor compounds has led to the identification of highly effective N,N'-substituted imidazolium salts with comparable activity to that of cisplatin, which has been used as a chemotherapeutic agent for decades. The high toxicity of present cancer treatments has prompted the investigation into other compounds with similar efficacy. Select N,N'-bis(arylmethyl)-imidazolium salts have been shown to exhibit high anti-proliferative activity, yet these compounds have inferior aqueous solubilities. This dissertation describes the rational design and biological activity of N,N'-bis(arylmethyl)imidazolium salts with hydrophilic and hydrophobic substituents on the imidazole ring for the treatment of lung carcinomas and chronic urinary tract infections. Chapter I discusses the background and development of N,N'-substituted imidazolium salts within the field of antitumor research. Chapter II addresses the synthesis and anti-proliferative activity of C4(C5) substituted N,N'-bis(arylmethyl)-imidazolium salts with hydrophilic or lipophilic groups on the imidazole ring. In vitro activity of these seventeen imidazolium salts against select non-small cell lung cancer cell (NSCLC) lines (NCI-H460, HCC827, and NCI-H1975) was analyzed by biological assays. It was determined that the phenyl substituents at the C4(C5) positions increased the in vitro antitumor activity of these salts to create highly active compounds. Chapter III is designated to the synthesis and anti-proliferative activity of thirty-one N,N'-bis(arylmethyl)benzimidazolium salts against NCI-H460, HCC827, NCI-H1975, and NCI-A549 lung cancer cell lines. Our data confirms that naphthylmethyl substituents at the nitrogen atoms (N1(N3)) and highly lipophilic substituents at the carbon atoms (C2 and C5(C6)) can generate benzimidazolium salts with anti-proliferative activity c (open full item for complete abstract)

PhD, University of Cincinnati, 2015, Medicine: Molecular and Developmental Biology

Many cancers are driven by oncogenic K-Ras, yet K-Ras has remained largely undruggable. In this dissertation we explore inhibiting K-Ras signaling by targeting downstream signaling pathways, namely the RhoA and RhoC GTPase pathways. Numerous cellular studies have indicated that RhoA signaling is required for oncogenic Ras-induced transformation. To date very limited data exist to genetically attribute RhoA function to Ras-mediated tumorigenesis in mammalian models. In order to assess whether RhoA is required for K-Ras-induced lung cancer initiation, we utilized the K-RasG12D Lox-Stop-Lox murine lung cancer model in combination with the conditional RhoAflox/flox and RhoC-/- knockout mouse models. We found that deletion of RhoA, RhoC or both did not adversely affect normal lung development. Moreover, we found that deletion of either RhoA or RhoC alone did not suppress K-RasG12D induced lung adenoma initiation. Rather, deletion of RhoA alone increased lung adenoma formation, whereas dual deletion of RhoA and RhoC together significantly reduced K-RasG12D induced adenoma formation. Deletion of RhoA appears to induce a compensatory mechanism that exacerbates adenoma formation. The compensatory mechanism is at least partly mediated by RhoC. These results are in contrast to RhoA knockdown experiments we performed in human lung cancer cell lines, which show dramatic inhibition of malignant phenotypes with RhoA loss. Taken together, this dissertation work suggests that targeting of RhoA alone may allow for compensation and a paradoxical exacerbation of neoplasia, while simultaneous targeting of both RhoA and RhoC is more likely to inhibit oncogenic K-Ras driven lung cancers.

Doctor of Philosophy, The Ohio State University, 2015, Biophysics

This report hence examines the expression and function of IkappaBzetain lung inflammation. We start by exploring the regulation of IkappaBzeta in lung epithelial cells, followed by evaluating its role in three different models of lung inflammation: allergy, infection and mechanical injury. In conclusion, this report highlights the expression, function and regulation of IkappaBzetain in various models of lung inflammation including allergy, infection and mechanical injury.

PhD, University of Cincinnati, 2008, Medicine : Pathobiology and Molecular Medicine

Airway remodeling is associated with the vast majority of lung diseases including chronic obstructive pulmonary disease, asthma, and lung cancer. Epithelial regeneration is a key component in airway remodeling after injury. Accordingly, deregulated epithelial cell proliferation, survival, and differentiation play a prominent role in the pathogenesis of chronic lung disease. The lung epithelium is composed of specialized cell types that result from coordinate regulation of progenitor/stem cell proliferation and differentiation. The retinoblastoma gene product (Rb) regulates both proliferation and differentiation, and is inactivated in nearly all cases of lung cancer strongly implicating Rb as a critical regulator in the lung epithelium. The objective of this dissertation project was to test the hypothesis that Rb is essential for proper lung epithelial repair after injury. Rb ablation was targeted to the lung epithelium using a tetracycline regulated Cre/LoxP system, and epithelial injury was induced with naphthalene to mimic human lung disease. These studies demonstrate that although Rb is not required for establishing and maintaining epithelial quiescence during homeostasis, Rb is essential for establishing quiescence during epithelial repair after injury. Rb ablation during development and in the postnatal lung had similar effects providing evidence that timing of Rb loss was not critical to the phenotypic outcomes, and that the injury induced phenotype was not secondary to compensatory alterations occurring during development. After establishing this critical role for Rb in epithelial remodeling after a single episode of injury, Rb function was assessed in a chronic injury model to more closely mimic human lung disease. These studies led to the discovery of previously unknown effects of the highly utilized naphthalene injury model; namely naphthalene injury results in altered epithelial composition and subsequent inflammation. Importantly, Rb dependent sustained (open full item for complete abstract)

Master of Science, The Ohio State University, 2010, Chemistry

The ability of the lungs to function normally can be rooted back to its physiological and molecular components. The natural lung surfactants that lines the alveolar walls reduce the surface tension in the alveoli, prevent the collapse of alveolar walls and maintain a large surface area for an easy access of oxygen into the bloodstream. The absence of lung surfactants results in the collapse of the alveoli and eventually causes the lungs to become stiff. This situation impairs the easy exchange of gases to and from the bloodstream and causes life threatening diseases. Different replacement lung surfactants (RLS) are currently used worldwide to supplement the lack of natural lung surfactants, especially in premature babies. RLS vary in their formulations and can be derived from animal or synthetic sources. The results presented in this work demonstrate the behavior of the different lung surfactant model systems on water and physiological buffer subphase acquired through surface pressure-area isotherm and Brewster angle microscopy. Shifting of the surface-pressure area isotherms of all lung surfactant model systems towards higher mean molecular areas when spread on the buffer subphase was observed. Various theories explain such shifting and are explored in this thesis. Furthermore, the fluidizing effect of POPG and condensing effect of PA in their binary and ternary mixtures were observed and reported. Also, the effect of KL4 (a 21 amino acid peptide that is believed to mimic the structure of the surface protein SP-B in natural lung surfactants) in the ternary mixture of DPPC-POPG-PA spread on the buffer subphase was explored and observed to play a part in the formation of more condensed phase in the system.

Doctor of Philosophy, The Ohio State University, 2008, Pharmacy

The long-term goal of this study is to identify a potential innovative therapeutic target to prevent or treat Acute Respiratory Distress Syndrome (ARDS), a condition associated with systemic inflammation and characterized by extensive lung epithelial damage leading to protein enriched fluid influx into the lung alveolar space and compromised ventilation [1, 2]. The rapid progression of acute lung injury at the onset of ARDS is one of the reasons responsible for the high mortality of ARDS [3]. A variety of strategies to treat and manage ARDS has been extensively investigated. However, patient survival has not been improved. Based on the previous work of our laboratory and numerous studies that identify the cell survival phosphatidylinositol 3'-kinase (PI3K)/Akt pathway as a vital survival axis in the lung epithelium, we focused on this pathway as a molecular target to prevent lung epithelium dysfunction [4-6]. Phosphatase and Tensin homolog deleted on chromosome Ten (PTEN) is a phosphase that is known to be a negative regulator of the PI3K/Akt survival pathway by dephosphorylation of PI(3,4,5)P3 at the 3 position in the inositol ring thereby inactivating this second messenger [7, 8]. PTEN is enriched in the lung epithelium as observed in our preliminary data. The Knoell laboratory previously reported that activation of the PI3K/Akt pathway promotes lung epithelial cell survival during inflammatory stress [4]. Based on this, we hypothesized that inhibition of PTEN by specific PTEN inhibitors would be a rational therapeutic strategy to facilitate normal lung epithelium cell function under stress conditions. The PTEN inhibitor, bisperoxovanadium, was first reported in 2004 documenting PTEN target specificity in cell culture models [9]. In our study, the same PTEN inhibitor and a related analogue were utilized and studied for their in vitro and in vivo potential to inhibit PTEN, activate the PI3K/Akt signaling axis and/or other downstream signaling pathways of PTEN, and (open full item for complete abstract)

Doctor of Philosophy, The Ohio State University, 2004, Medical Microbiology and Immunology

The work presented in this dissertation aims to characterize molecular pathways involved in murine lung development, murine lung cancer development, and embryonic cancer development, in order to better understand the complex processes involved in the development and progression of lung cancer. Oligonucleotide microarray-based gene expression analysis was conducted across various stages of murine lung development to identify regulatory pathways at key developmental time points. Using Affymetrix U74Av2 Murine GeneChip® microarrays, 1,346 genes and ESTs were identified as having a significant change in expression. We also performed microarray analysis on a murine model of lung carcinogenesis, again using Affymetrix U74A GeneChips®. Epithelial lung cancers were induced in mice using NNK, a common carcinogen found in tobacco smoke, and gene expression analysis was performed on various stages of lung tumors. This analysis yielded 20 effectors involved in lung tumorigenesis and 50 effectors specific for tumor progression. We then compared the murine lung tumor results to the lung development study. This identified 24 developmentally regulated genes whose aberrant expression could contribute to tumor phenotype. To assess the relevance of murine lung cancer models in the study of human adenocarcinoma formation, we compared our murine lung tumor data to a study examining gene expression in human lung tumor samples and identified 39 genes with similar expression changes in human and murine lung tumors. This work links murine lung tumorogenesis to murine lung development and human lung tumor formation. Finally, we examined the formation of teratocarcinomas, embryonic cancers, to understand how dysregulation of the embryonic environment leads to tumor formation. We identified 3 gene methylation events by Restriction Landmark Genome Scanning that may play a role in teratocarcinoma development from embryonic stem cells. We performed microarray gene expression analysis on the tissu (open full item for complete abstract)

Doctor of Philosophy in Medical Sciences (Ph.D.), University of Toledo, 2005, College of Graduate Studies

Targretin was tested for its ability to prevent lung tumors in A/J mice induced by vinyl carbamate. Doses 30-300 mg/kg decreased tumors multiplicity by greater than 19%. Administering 200 mg/kg Targretin from weeks 4-19 and 4-25 decreased the multiplicity of tumors from 35.3 ± 1.43 to 29.1 ± 1.51 and 25.0 ± 0.93, respectively. Targretin decreased tumor size in 4-25 and 23-25 wk prevented and reversed DNA hypomethylation in lung tumors. Microarrays analysis indicated that Targretin short-term treatment had a greater effect on mRNA expression than long-term treatment. In lung tumors, Targretin decreased expression of p16INK4, EP3, Caspase-3, Dnmt-3, survivin, Cyclin B2, Cyclin E1, iNOS and ER-"Α", with short-term treatment being more effective than long-term treatment. Short-term treatment increased expression of Apolipoprotein D, Cyp26b, and Fabp-4, while long-term treatment only increased expression of Apolipoprotein D and Cyp26b. Budesonide and R115777 were evaluated for their usefulness in preventing vinyl carbamate-induced lung tumors in A/J mice. One week after the second dose of vinyl carbamate, mice received 60 or 100 mg/kg R115777 (gavage), 0.8 or 1.6 mg/kg budesonide (diet), or the two drugs combined treatment until sacrificed at 20, 28 and 36 weeks. Other mice received the drugs for two weeks prior to sacrifice at 20 wk. The rank order for prevention of lung tumors was the combined treatment > budesonide > R115777 (only at 20 wk). The drugs prevented DNA hypomethylation in lung tumors. While p21waf1/cip1 and Hoxa5 were methylated, APC, EGFR, RAR-"Β", DAPK and Fhit genes were not.