Doctor of Philosophy, The Ohio State University, 2023, Molecular, Cellular and Developmental Biology

Chronic lymphocytic leukemia (CLL) is the most prevalent adult leukemia in the western world, accounting for more than 4000 deaths in the United States every year. It is a malignancy of CD5+CD23+CD19+ B lymphocytes, characterized by activation of B cell receptor (BCR) signaling that in turn activates several downstream cell survival pathways, and migration of these B cells (B-CLL cells) to pro-survival niches like the bone marrow, lymph nodes and spleen. The only curative therapy is allogeneic hematopoietic stem cell transplantation, but this therapy is associated with common risks like graft-versus-host-disease and pulmonary complications. BCR signaling inhibitors are effective agents for CLL treatment, but therapeutic resistance and relapse remain problematic, necessitating the identification of new CLL targets that can bypass current disease resistance. Sialic-acid-binding immunoglobulin-like lectins (Siglecs) are a family of cell surface glycoproteins that demonstrate cell-type specific expression and can modulate receptor signaling. Many studies have shown the importance of Siglecs in tumor immunosurveillance including immunosuppression, thereby making them attractive anti-cancer molecular targets. Our study focuses on evaluating a novel Siglec member, Siglec-6, which was recently found to be upregulated on the surface of B cells from CLL patients but not on B cells from healthy donors. CLL-specific upregulation of Siglec-6 thus makes it a valuable therapeutic target and warrants the development of transgenic mouse models and cell line systems to further explore the biological role of Siglec-6. While Siglec-6 has been extensively studied in trophoblastic cells, mast cells and bladder cancer cells, the physiological role of Siglec-6 in immune cells is still poorly understood. In the first part of this dissertation, we utilized our novel Siglec-6 transgenic mouse models to identify a specific role for Siglec-6 in regulating B cell functions. Siglec-6 transgenic (open full item for complete abstract)

Committee: Natarajan Muthusamy (Advisor); Meixiao Long (Committee Member); Lalit Sehgal (Committee Member); Paul Martin (Committee Member) Subjects: Cellular Biology; Molecular Biology

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

Chronic lymphocytic leukemia (CLL) is the most common form of adult leukemia and is characterized by the accumulation of mature CD19+CD5+ B cells that acquire a variety of chromosomal and genomic aberrations. This gives rise to many advantages to CLL cells including the ability to have enhanced proliferation and be resistant to apoptosis. These discoveries led to the development of targeted therapies for these aberrant pathways including Brutons Tyrosine kinase (BTK) inhibitor, ibrutinib, and B cell lymphoma 2 (BCL-2) inhibitor, venetoclax. However, even with targeted therapies, some subgroups of the CLL patients classified as high-risk need treatment for progressive disease or have genomic aberrations that lead to a poor outcome. One such group are patients with a deletion of chromosome 17 (del17p) leading to the loss of one allele of tumor suppressor protein TP53. This occurs in about 10% of patients at diagnosis and increases to 30% in relapsed/refractory disease. Additionally, about 83% of patients with a del17p acquire a mutation on their second TP53 allele at one of several sites within the DNA binding domain. Little is known of the role of these “hotspot” mutations (e.g., R175H, R248Q/W, R273H) in CLL. Clinically, patients with del17p/mutant p53 have worse survival, disease progression, and frequently relapse on targeted therapies such as ibrutinib. While relapse to ibrutinib is mainly caused by acquired mutations in BTK or its downstream target PLCγ2, we hypothesized that CLL with mutant p53 is a key driver of resistance and progression. To investigate this, we utilized the techniques of RNA sequencing RNA-seq and chromatin immunoprecipitation sequencing (ChIP-seq) to uncover unique transcriptionally regulated targets of mutant p53 in CLL. We identified two key proteins that are potential key downstream effectors of CLL patient cells with mutant p53, BCL2L1 (BCL-xL), and PRKCB (PKC-β). To determine whether mutations in p53 were causal in the observed increa (open full item for complete abstract)

Committee: Jennifer Woyach (Advisor); Deepa Sampath (Advisor); Robert Baiocchi (Committee Member); Jeffrey Parvin (Committee Member) Subjects: Biomedical Research

Doctor of Philosophy, The Ohio State University, 2020, Molecular, Cellular and Developmental Biology

Chronic lymphocytic leukemia is the most common type of leukemia in adults in the United States. Characterized by the accumulation of mature B cells, this malignancy requires the presence of a supportive microenvironment that promotes cell proliferation and survival. Nurse-like cells (NLCs) are the CLL tumor-associated macrophages, whose role has been explored for the last 20 years. Nevertheless, there is still a long way to understand their biology and to study new strategies that modify their supportive role, for better therapeutic efficacy. Here, we studied the potential use of targeting NLCs for therapeutic approaches. In the first part, we explored the nature of NLC development and found a therapeutic approach to block their differentiation and supportive role in CLL. We found that NLC differentiation is characterized by a significant loss of methylation, especially in AP-1 transcription factor binding sites. This finding further led us to the discovery that the MEK signaling pathway may be responsible for NLC differentiation and that its inhibition results in decreased disease burden in a mouse CLL model. Thus, inhibition of MEK signaling, especially with the FDA approved trametinib, could potentially offer a therapeutic option. We finally found that during NLC differentiation, there are significant changes in gene expression, some of them related to the MEK signaling pathway; this may be of use to further explore potential therapeutic targets to inhibit NLC development. In a second study, we focused on the regulation of antibody-mediated responses by inhibitory, checkpoint receptors. NLCs, similar to macrophages, have the potential to phagocytose antibody-coated CLL cells. With the increase of therapeutic antibody use in the clinic and the critical role of the anti-CD20 rituximab in CLL therapy, understanding how the IgG antibody receptors (FcγR) are regulated by checkpoint molecules is of importance. In this context, we found that the platelet endothelia (open full item for complete abstract)

Committee: Susheela Tridandapani Ph.D. (Advisor); Jonathan Butchar Ph.D. (Committee Member); Christopher Oakes Ph.D (Committee Member); Jennifer Woyach M.D. (Committee Member); Santiago Partida-Sánchez Ph.D. (Committee Member) Subjects: Immunology; Oncology

Doctor of Philosophy, The Ohio State University, 2020, Molecular, Cellular and Developmental Biology

Epigenetic gene regulation enables multicellular organisms to develop from a single cell. Epigenetic modifications refer to stable, yet reversable, changes to the genome that do not alter the DNA sequence. These function to control the accessibility of the genome to transcriptional machinery. DNA methylation is an epigenetic modification critical for control of development and defects are common in diseases such as cancer. Chronic lymphocytic leukemia (CLL) and acute myeloid leukemia (AML) are two of the most common leukemias in adults. Both display a high degree of clinical heterogeneity, and global DNA methylation patterns have identified distinct biological subtypes in each disease. Identification of these patterns requires methods that interrogate the methylation from across the genome. However, because these methods are often too costly and require complex data analysis to process and interpret the results making it difficult to analyze large sample cohorts, I developed a novel method, the Methylation-iPLEX (Me-iPLEX), for analyzing DNA methylation from multiple regions of the genome in a high-resolution and high throughput manner. The epigenetic subtypes observed in CLL largely reflect the natural history of the cell of origin. The efficient nature of the Me-iPLEX enabled me to interrogate the epigenetic subtypes of 1286 CLL patients and examine the prognostic significance of the epigenetic subtype across disease stages and with multiple therapies. The large sample size also enabled me to identify several biological traits associated with the subtypes as well as determining that epigenetic subtypes retained prognostic significance after stratifying by biologically related biomarkers. Past studies analyzing DNA methylation patterns in AML identified patterns associated with common genetic aberrations. These aberrations currently form the basis of our understanding of disease mechanisms and are used to predict treatment response. I analyzed Illlumina genom (open full item for complete abstract)

Committee: Christopher Oakes PhD (Advisor); John Byrd MD (Advisor); Ramiro Garzon MD (Committee Member); Kevin Coombes PhD (Committee Member) Subjects: Bioinformatics; Biology; Genetics; Molecular Biology; Oncology

Doctor of Philosophy, The Ohio State University, 2020, Biomedical Sciences

Chronic lymphocytic leukemia (CLL) is a disease of abnormal B lymphocyte accumulation that mainly affects older adults with a median age of diagnosis of 70. In the last few years alone, targeted immunotherapy with novel agents such as ibrutinib, a Bruton's Tyrosine Kinase inhibitor, and has supplanted first line chemoimmunotherapy for most genetic and patient subgroups. Even though the prognosis of CLL is now favorable, up to 50 percent of CLL patients eventually discontinue therapy due to 1) relapse and refractory disease and 2) ibrutinib intolerance due to the non-specific nature of small molecule therapy that also suppresses normal immune cell functions causing immune suppression and serious infections even while patients are in remission. For patients who must discontinue ibrutinib, disease control remains clinically challenging. Despite inducing deeper and longer remissions in most patients, most ibrutinib treated patients have minimal, but detectable measurable residual disease (MRD) in circulation. Close to 20% of these patients eventually progress while on ibrutinib and more than 80% of those who progress show subclonal acquisition of mutations in BTK or BTK dependent signaling pathways such as PLCG2 that can appear as early as 9 months before clinical symptoms. Timely detection of these drug resistant variants is critical for preventing disease progression and relapse. While resistant clones evolve from small, pre-existing tumor subclones, other studies have suggested that CLL tumor clones can independently originate from leukemic stem and progenitor cells. However, the rarity of resistant subclones and leukemic stem and progenitor cells makes them difficult and expensive to monitor and characterize by available current genetic sequencing techniques. Therefore, we developed a fast and cost effective rare cell sequencing pipeline (LC-FACseq) in order to monitor the initiation and progress of clonal resistance in long-term ibrutinib treated CLL patients an (open full item for complete abstract)

Committee: Natarajan Muthusamy (Advisor); John, C Byrd (Advisor); Christopher Oakes (Committee Member); Michael Ostrowski (Committee Member); Michael Caligiuri (Committee Member) Subjects: Biomedical Research

Doctor of Philosophy, The Ohio State University, 2018, Molecular, Cellular and Developmental Biology

Chronic lymphocytic leukemia (CLL) is the most common adult leukemia in the western world, representing roughly a third of all new leukemia cases totaling approximately 20,000 in the United States every year. It is characterized by B cell lymphocytosis with a CD5+ immunophenotype, various cytopenias stemming from impaired hematopoiesis, and profound immune suppression leading to early death. Accumulation of CLL cells is attributed to an apoptosis defect, which is thought to be due to constitutive survival signaling downstream of the B cell receptor (BCR) pathway and upregulation of pro-survival proteins. Proliferation of CLL is attributed to activation of the Nuclear Factor Kappa-Light-Chain-Enhancer of Activated B Cells (NF-¿B) pathway; occurring in opportune niches of the bone marrow, spleen and lymph nodes. Prostate Apoptosis Response 4 (Par-4) is a known tumor suppressor protein and is upregulated in CLL, making it an attractive target for therapy. Par-4 is thoroughly described as having potent anti-neoplastic activity in solid tumors, but exploration into its role in hematologic malignancies is restricted to very few studies. The seminal study assessing the relevance of this tumor suppressor pathway in hematological malignancies found that Par-4 protein levels were more abundant in CLL B cells than healthy controls. This finding is in stark contrast to the observed reduction in protein level in the vast majority of solid tumors assessed for Par-4 expression. Recently Par-4 expression has been positively correlated with favorable response to treatments that target proliferation signals and expression of anti-apoptotic proteins. These findings have peaked interest in Par-4 in CLL, for which small molecule inhibitors (SMI) that target proliferation and survival pathways, such as Ibrutinib and Venetoclax which inhibit BCR signaling and anti-apoptotic B-cell lymphoma 2 (BCL2) protein respectively, are effective for treatment. The Eµ-TCL1 mouse is a B cell leu (open full item for complete abstract)

Committee: Natarajan Muthusamy (Advisor); John Byrd (Committee Member); Deepa Sampath (Committee Member); Ramesh Ganju (Committee Member) Subjects: Biology; Cellular Biology; Genetics; Immunology; Molecular Biology; Oncology

Doctor of Philosophy, The Ohio State University, 2018, Psychology

Leventhal's Self-Regulatory Model of Illness Behavior (1980) proposes that, in response to a health-relevant stimulus such as a physical symptom or disease diagnosis, individuals generate a mental representation of the stimulus, or illness perception, which guides coping behaviors and influences psychological and physical health outcomes. Despite extensive research linking illness perceptions to coping and health in several disease groups, lesser attention has focused on better understanding determinants of illness perceptions themselves. The goal of the current project was to test a fundamental postulate of self-regulatory theory, which suggests that illness perceptions are influenced primarily by somatic characteristics of the illness stimulus (e.g., symptom type and severity), prior experiences with the stimulus (e.g., treatment success or failure), and changes in the stimulus over time. To do so, two studies were conducted, both in samples of patients with chronic lymphocytic leukemia (CLL). Using a cross-sectional design, Study 1 contrasted illness perceptions among CLL patients (N=330) from three groups differing in symptom severity and prior CLL experiences: active surveillance (n=100), initiating a first treatment (n=78), and initiating treatment for relapsed/refractory disease (n=152). Analysis of variance revealed that, while consequences, identity (symptoms), and illness concern were poorer among patients at each successive phase of treatment, perceptions of how well one understands CLL (coherence) and how long CLL will last (timeline) were poorest among those earliest in the trajectory (i.e., active surveillance). Patients initiating a first treatment believed most strongly that they could personally control CLL (personal control) and that treatment would be helpful (treatment control). Study 2, using a longitudinal, single group design, examined specifically the role of somatic stimulus severity among relapsed/refractory CLL patients (N=152) initiating (open full item for complete abstract)

Committee: Barbara Andersen (Advisor); Charles Emery (Committee Member); Baldwin Way (Committee Member) Subjects: Psychology

Doctor of Philosophy, The Ohio State University, 2018, Biomedical Sciences

Chronic lymphocytic leukemia (CLL) is a cancer of monoclonal B cells caused by dysregulated proliferation within the bone marrow which disrupts normal hematopoiesis leading to anemia, immune deficiencies, and increased rates of morbidity and mortality. With approximately 150,000 affected individuals and an annual incidence exceeding 20,000 in the United States, CLL is the most prevalent leukemia in the western hemisphere. Recent appreciation for the extent to which B cell receptor (BCR) signaling contributes to the pathogenesis of CLL has spurred the development of small molecule inhibitors which block signaling initiated at the BCR. One such molecule designed to abrogate BCR signaling is ibrutinib, an irreversible inhibitor of Bruton's tyrosine kinase (BTK). Patients treated with ibrutinib benefit from durable remission and prolonged progression free survival. However, despite ibrutinib's multiple Breakthrough Therapy Designation, it is not a panacea and resistance to therapy occurs in many patients. Resistance to ibrutinib is most commonly mediated by mutation of BTK's Cys481 amino acid to serine (C481S), which prevents ibrutinib's covalent binding, reducing its potency. The kinase inhibitors GDC-0853 and ARQ 531 reversibly and potently inhibit BTK at low nanomolar concentrations. Like ibrutinib, these compounds are mildly cytotoxic, reduce chemotaxis, and abrogate NF-kB mediated gene transcription. Because GDC-0853 and ARQ 531 are reversible inhibitors which do not rely upon the Cys481 amino acid of BTK for activity, we hypothesized that these compounds would maintain efficacy in mutated C481S BTK. As expected, both GDC-0853 and ARQ 531 inhibit C481S BTK in biochemical assays, as well as cell lines and patient cells expressing C481S BTK. While GDC-0853 possesses exquisite specificity for BTK, ARQ 531 is a relatively promiscuous kinase inhibitor which targets multiple SRC and TEC family kinases. Interestingly, their distinct inhibitory profiles bestow (open full item for complete abstract)

Committee: John Byrd (Advisor); Jennifer Woyach (Advisor); Robert Baiocchi (Committee Member); William Carson III (Committee Member) Subjects: Biomedical Research

Doctor of Philosophy, The Ohio State University, 2017, Pharmacy

Chronic lymphocytic leukemia (CLL) is the most prevalent adult leukemia in the western world. The treatment strategies of CLL have undergone a paradigm shift in the last decade. Without a disease defining gene abnormality, the Achilleas heels of CLL is its microenvironment dependency. Upon discovering the importance of CLL-microenvironment cross-talk and essential survival B cell receptor (BCR) pathways, small molecule inhibitors that target BCR pathways were soon developed and showed profound activity in preclinical and clinical studies. Several agents that target BCR pathways also reverse tumor related immune suppression. Idelalisib is one such therapy directed at phosphoinositide 3-kinase isoform d, an essential component of BCR signaling in normal and transformed B-cells and essential for the activation of regulatory T cells. CLL is dependent upon BCR signaling and mediates profound immune suppression and tumor tolerance. Idelalisib is a PI3K p110d inhibitor with significant clinical benefit and also toxicities resembling autoimmunity. Using a PI3K p110delta and p110gamma inhibitor IPI-145, we show that PI3K p110delta/p110gamma blockade in leukemia cells overcomes microenvironmental BCR- and CD40L- stimulation, antagonizes pro-survival AKT pathway and induces selective cytotoxicity to leukemia cells. PI3K p110delta/p110gamma blockade reduces TCR-induced T cell proliferation and cytokine production, suggesting PI3K p110delta/p110gamma have dual roles in the leukemic and normal immune compartment. PI3K p110delta/p110gamma inhibition does not impair natural killer cell- mediated cellular cytotoxicity. Most importantly, PI3K p110delta/p110gamma inhibition can overcome ibrutinib resistance due to the BTK C481S mutation. Using different genetic mouse models, we demonstrate that global inactivation of p110delta blocks leukemia development, confirming that p110delta is critical for CLL initiation and progression. Additionally, blocking p110delta acti (open full item for complete abstract)

Committee: Amy Johnson Ph.D. (Advisor); John Byrd M.D. (Advisor); A Phelps Ph.D. (Committee Member); Michael Ostrowski Ph.D. (Committee Member) Subjects: Biomedical Research; Immunology; Pharmaceuticals

Master of Arts, The Ohio State University, 2016, Psychology

Chronic stress has been commonly observed in cancer patients and is associated with immune system down regulation. The effect of stress on immunity in hematologic cancers such as chronic lymphocytic leukemia (CLL) has not been studied despite the role of immune system dysfunction in CLL's pathogenesis. In a phase II clinical trial, 154 patients with relapsed/refractory CLL received ibrutinib, provided blood samples, and completed a self-report measure of psychological stress specific to cancer over an 18-month treatment period (nine assessments).Targeted treatments like ibrutinib have been effective in reducing disease progression in CLL, despite the occurrence of lymphocytosis, which is an increase in absolute lymphocyte counts (ALC) and marker of progressive disease. Controlling for demographic, health status, number of prior treatments, and CLL genetic risk (del17p) factors, random changepoint models were estimated to evaluate the impact of stress on ALC trajectories. Stress was associated with pretreatment ALC (ß_0 = 0.13; 95% CI = 0.02, 0.25) but did not impact the timing of lymphocytosis (fx1= 0.03, CI = -0.15, 0.22), or the treatment response before (ß_x1= -0.11, CI = -0.23, 0.01) and after (dx1=0.10, -0.01, 0.22) lymphocytosis. Stress affects pre-treatment ALC but has little impact on ALC trajectories after beginning drug therapy. Additional analysis showed that lymphocytosis occurs later in the treatment trajectory for individuals classified as drug non-responders by 18-months compared to those regarded as drug responders (fx2 = -0.95; CI= -1.50, -0.41), though it is unclear whether clinical or demographic risk factors can predict these groups. Results suggest patients exhibit similar ALC trajectories after ibrutinib initiation. Distress screening and management should be initiated prior to cancer treatments.

Committee: Barbara Andersen PhD (Advisor); Julian Thayer PhD (Committee Member); Baldwin Way PhD (Committee Member) Subjects: Psychology

Doctor of Philosophy, The Ohio State University, 2017, Biomedical Sciences

Chronic lymphocytic leukemia (CLL) is the most common type of adult leukemia in the United States. CLL is a highly heterogeneous disease; patients may progress within months or live out their lives without requiring intervention. As most patients are asymptomatic and early stage at diagnosis, biomarkers are important for predicting outcomes for these patients. Biomarkers are cellular, biochemical or molecular alterations that are measureable indicators of disease processes or pharmacological responses. We sought to identify novel biomarkers for CLL, particularly biomarkers associated with therapeutic response. We first sought to identify and interrogate the prognostic significance of chromosomal abnormalities in CLL. Using metaphase cytogenetics we described a novel chromosomal abnormality, the jumping translocation, occurring in 3% of our CLL population. We found that this abnormality contributed to patients acquiring the aggressive disease markers, complex karyotype and deletion of 17p. Patients with jumping translocations had aggressive disease, with a median time to treatment of 11.5 months. Our second approach for interrogating chromosomal abnormalities utilized fluorescence in situ hybridization (FISH). Using FISH we examined two chromosomal abnormalities, gain of 2p and near-tetraploidy (~4 copies of each chromosome within a cell), for their ability to predict for progression on the Bruton's tyrosine kinase inhibitor, ibrutinib. Ibrutinib shows substantial response rates in relapsed/refractory CLL as well as previously untreated patients; however, there remains a subset of patients who progress on ibrutinib. Patients who progress on ibrutinib do so with progressive CLL or through Richter's transformation, a transformation to an aggressive lymphoma. Gain of 2p has been previously reported as associated with Richter's transformation. Near-tetraploidy has never been described in CLL; however, it does occur in various lymphomas. We examined patient sa (open full item for complete abstract)

Committee: John Byrd (Advisor) Subjects: Biomedical Research

Doctor of Philosophy, The Ohio State University, 2016, Public Health

Various exposures have been investigated by epidemiologic studies as risk factors for leukemia incidence, however studies focusing on and therefore findings particular to Small Lymphocytic Lymphoma (SLL) and Chronic Lymphocytic Leukemia (CLL) have been sparse. In fact, according to the NCI, there are only a few established risk factors for CLL/SLL: 1) being middle-aged or older, male, or white; 2) a family history of CLL or cancer of the lymph system; and 3) having relatives who are Russian Jews or Eastern European Jews. As none of these are risk factors that can be altered with lifestyle changes, we sought to explore potential and likely risk factors that can be modified with behavior. Using the Women's Health Initiative (WHI) and applying an age and race matched, nested, 1:4 case-control design, we investigated CLL/SLL risk in postmenopausal women with three specific aims of interest: personal habits, comprising diet, drinking habits (including alcohol and coffee, both which have potential biological activity in leukemogenesis), and exercise; hormonal exposures, such as oral contraceptives (OC) and hormone therapies (HT); and pesticide exposures. These areas were chosen because there is a great need to understand 1) why CLL/SLL is significantly more prevalent in industrial countries compared to developing countries, and 2) why men have a two-fold increase in their risk of developing CLL/SLL. Women enrolled on WHI clinical trials who consumed coffee on a regular basis had lower risk of CLL/SLL (odds ratio (OR) = 0.73, 95% confidence interval (CI): 0.51, 1.05; P=.09), compared to non-coffee drinkers. Past oral contraceptive use (OR=0.74, 95% CI: 0.56, 0.96; P=.03) and obesity (OR=0.71, 95% CI: 0.53, 0.94; P=.20) both showed to be protective against CLL/SLL, whereas past estrogen use (OR=1.32, 95% CI:1.02, 1.71; P=.04) increased the risk. We did not find any significant associations with other personal habits and CLL/SLL risk, such as alcohol use, dietary factors (open full item for complete abstract)

Committee: Electra Paskett PhD (Advisor); Stanley Lemeshow PhD (Committee Member) Subjects: Epidemiology

Doctor of Philosophy, The Ohio State University, 2016, Integrated Biomedical Science Graduate Program

Chronic Lymphocytic Leukemia (CLL) is currently an incurable disease. The current front-line therapy is chemoimmunotherapy, which is associated with significant toxicity and immunosuppression. Targeted therapeutics have the potential to provide well-tolerated therapies, however the lack of a unifying genetic alteration in CLL has made target identification difficult. Activation of B cell receptor signaling (BCR) is aberrant leading to enhanced pro-survival signaling. An integral kinase in the BCR pathway, Bruton agammaglobulinemia Tyrosine Kinase (BTK) was identified as a viable target in CLL. Targeting BTK with ibrutinib, an irreversible inhibitor, can decrease pro-survival signaling, has significant clinical activity and is now FDA approved. Some patients on long-term ibrutinib therapy acquire a point mutation in ibrutinib's binding site (BTKC481S). This mutation renders ibrutinib a reversible inhibitor reducing the efficacy of the drug. Determining the transcriptional and phenotypic differences after alteration of BTK is integral for understanding the role of BTK in CLL progression and development of targeted agents to subvert resistance. It is known that ibrutinib targets CLL survival signaling, but it is not known how targeting BTK alters the microRNA (miR) profile. Lymphocytes from ibrutinib treated patients were collected pre- and post-therapy and were analyzed by miR Nanostring. A unique profile of differentially expressed miRs was identified. OncomiR, miR-155 was confirmed to be down-modulated with ibrutinib therapy. Analysis of miR-155 expression was done on responding versus relapse patients on long-term ibrutinib therapy. miR-155 expression remained down-modulated in responding patients, but was elevated in relapsed patients. We conclude that miR-155 can be favorably down-modulated by ibrutinib treatment and may play a role in resistance. Another novel miR identified was tumor suppressive, miR-126. In our studies, we show that miR-126 is reduced wi (open full item for complete abstract)

Committee: John Byrd (Advisor); Amy Johnson (Advisor); Flavia Pichiorri (Committee Member); Albert de la Chapelle (Committee Member) Subjects: Biomedical Research

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

Chronic lymphocytic leukemia (CLL) is the most prevalent form of adult leukemia and is considered incurable. While survival of patients has improved with newer therapies, all patients eventually relapse and continue to have poor outcomes with additional therapies. Ibrutinib is a new, targeted therapy for CLL that has demonstrated dramatic efficacy with little toxicity for those with relapsed/refractory CLL. Patients with CLL are understudied and little is known about their psychological and physical functioning, especially among those with relapsed/refractory disease. Furthermore, little is known about the impact of psychological factors on immunological factors that influence disease progression in hematologic malignancies. Research indicates that cytokine-driven processes of inflammation and angiogenesis influence disease progression. In particular, interleukin (IL)-6, tumor necrosis factor-alpha (TNF-alpha), and vascular endothelial growth factor (VEGF) are of interest. Understanding what factors may influence trajectories of psychological, physical, and immunological responses as patients undergo treatment for relapsed/refractory cancer is of utmost importance. According to the biobehavioral model of cancer, stress may be an individual difference variable that influences quality of life and immunity as patients undergo treatment. However, the relationship between stress and outcomes in patients with relapsed/refractory cancer is unclear. The current study examines the role of pre-treatment, cancer-specific stress on trajectories of psychological functioning, physical functioning, and selected cytokines as patients with relapsed/refractory CLL undergo treatment with ibrutinib. One-hundred fifty-one patients were recruited for a phase II drug trial of ibrutinib. Patients completed self-report measures 4 times over the first 5 months of therapy. IL-6, TNF-alpha, and VEGF were analyzed at 3 time points over the first 2 months of therapy in a subset of pa (open full item for complete abstract)

Committee: Barbara Andersen Ph.D. (Advisor); Robert Cudeck Ph.D. (Committee Member); Julian Thayer Ph.D. (Committee Member); Baldwin Way Ph.D. (Committee Member) Subjects: Psychology

Master of Arts, The Ohio State University, 2014, Psychology

Chronic lymphocytic leukemia (CLL) is the most prevalent adult leukemia and has no known cure. The course of CLL is atypical, often beginning with indolent disease that may or may not require immediate treatment, followed by repeated cycles of aggressive therapy, stable disease, and relapse. Despite these factors, knowledge of psychological functioning of these patients is limited. The current study examined the relation of illness perception to psychological distress and physical symptom burden in a sample of relapsed/refractory CLL patients (N=147) receiving Ibrutinib. Participants completed measures of illness perception (BIPQ), psychological distress (BDI-II, IES-R, SF-12 MCS) and physical symptom burden (SF-12 PCS, FSI, BPI) at baseline and two-months later. Regression analyses revealed that above and beyond disease relevant variables such as treatment history, age, and comorbidities, baseline illness perception was related to all measures of psychological distress and physical symptom burden at baseline (ps < .05), and all measures except for pain at follow-up (ps < .05). Follow-up analyses indicated that the individual illness perception components of consequences, emotional representation, identity, and illness concern might be particularly relevant to psychological and physical functioning of patients with CLL. Results highlight the critical role of subjective illness perception in the experience of distress and burden from physical symptoms, even among patients with cyclical and relapsing disease. Clinical implications and future directions to develop this line of research are discussed.

Committee: Barbara Andersen (Advisor); Steven Beck (Committee Member); Charles Emery (Committee Member) Subjects: Psychology

Doctor of Philosophy, The Ohio State University, 2012, Pharmacy

Chronic Lymphocytic Leukemia (CLL), representing 30% of leukemia, remains the most common hematologic malignancy in the western world. It is diagnosed by peripheral blood immunophenotyping with co-expression of biomarkers, such as CD5, CD19, CD20 and CD23, on B cell surface and with more than 5,000 B lymphocytes in one μl. The first-line treatment for CLL includes monotherapy or combined chemotherapy of alkylating agents (e.g. chlorambucil and cyclophosphamide), purine analogues (e.g. fludarabine and cladribine) and monoclonal antibody based immunotherapy (e.g. rituximab and alemtuzumab) CD20 directed therapeutic antibodies such as rituximab and ofatumumab are widely used in CLL therapy. However, there are still limitations of currently existing first-line treatments for CLL due to nonspecific cytotoxicity induced by drug or relapse caused by immunotherapy. Therefore, it is crucial to develop therapies that are efficiently and specifically targeting to the malignant B-CLL cells. Herein, we explore monoclonal antibody (mAb) and liposomal nanoparticles-based therapeutic strategies for CLL with the goal to achieve efficient and directed drug/gene delivery with minimal side effects. Firstly, a relatively new antibody, anti-CD37, was combined with one of the two classical antibodies, anti-CD19 or anti-CD20 to form dual-ligand immunoliposome (dILPs) delivery systems to show higher targeted delivery efficiency and more cytotoxicity to CLL cells compared to single-ligand immunoliposomes (sILPs). Among all combined dILPs, CD19/CD37 dILPs demonstrated the highest delivery efficiency to primary B cells from CLL patients. The improvement in specificity and efficiency made by dILPs revealed the advantages of combining mAbs with complementary features such as high expression level, unique specificity and fast internalization. A novel anti-ROR1 mAb, 2A2-IgG based immunoliposome (ILPs) delivery system specifically targeting to B-CLL cells was developed and tested. Besides investig (open full item for complete abstract)

Committee: Robert J. Lee PhD (Advisor); Natarajan Muthusamy PhD, DVM (Advisor); L. James Lee PhD (Committee Member); John. C Byrd MD (Committee Member); Mitch A. Phelps PhD (Committee Member) Subjects: Pharmaceuticals

Doctor of Philosophy, The Ohio State University, 2012, Pharmacy

Protein metabolism comprises the biochemical processes that regulate the synthesis of proteins, their post-translational modification and degradation. In cancer cells, pathways targeting protein metabolism are often deregulated to accumulate signals that promote survival. These changes are manifested in malignant cells by way of upregulation of protein synthesis, suppression of protein degradation and selective expression of anti-apoptotic, pro-proliferative and pro-survival proteins. B-cell malignancies such as chronic lymphocytic leukemia (CLL) and acute lymphocytic leukemia (ALL) are caused by the accumulation of B cells that are resistant to apoptosis. Both diseases are characterized by imbalanced expression of pro-apoptotic and anti-apoptotic Bcl-2 family members, constitutive expression of the nuclear factor NF-κB and mutations or deletions in the tumor suppressor p53 - signals that support the survival of leukemic B cells. Current therapies in CLL and ALL target normal immune cells in addition to malignant cells, causing profound immune suppression with an accompanying risk of lethal secondary infections. Furthermore, a common problem with most therapies is that patients who initially responded favorably relapse over time. To a large extent, this occurs in patients with advanced diseases that have p53 mutations in B cells, which become resistant to therapies dependent on wild-type p53 function. A major focus of therapeutic development has therefore been the investigation of agents that have minimal effects on T cells and are cytotoxic to B cells independent of p53 or overexpression of anti-apoptotic Bcl-2 family proteins. Two such therapeutic agents: silvestrol, a translation initiation inhibitor, and carfilzomib, a proteasome inhibitor, are introduced for the treatments of ALL and CLL in this thesis. The work presented herein provides proof of concept that drugs that affect protein metabolism pathways can selectively and potently target B cells over T cells (open full item for complete abstract)

Committee: John Byrd (Advisor); David Lucas (Advisor); Mitch Phelps (Committee Member); Kristy Ainslie (Committee Member) Subjects:

Master of Science, The Ohio State University, 2012, Allied Medical Professions

Jumping translocation (JT) is a rare cytogenetic aberration that can occur in hematologic malignancy. It involves the translocation of the same fragment of donor chromosome onto two or more recipient chromosomes typically in different cell lines. Here, for the first time, JTs are established as a type of recurrent abnormality occurring in chronic lymphocytic leukemia (CLL). The cytogenetic characteristics of JTs in CLL, the characteristics of the patient population where they are seen, and correlations with other clinicopathological findings are addressed. Twenty-six patients were identified with JTs at some period during their care. There were a total of 32 donor breakpoints with six patients exhibiting two unique donor breakpoints involved in JTs at the same time. Strikingly, 15 of the donor breakpoints were in 17p11.2. A total of 93 JTs were identified. Forty-one of these JTs resulted in dicentric or pseudodicentric chromosomes, 31 of which had 17p11.2 donor breakpoints. Patients with JTs in CLL appear to develop the disease at an early age and experience an aggressive disease state. These patients develop complex karyotypes and frequently show loss of the tumor suppressor gene TP53, both of which are considered poor prognostic indicators. The biology of JT formation is unclear and warrants further investigation.

Committee: Tammy Bannerman PhD (Advisor); Waller Kathy PhD (Committee Member); Huey-Jen Lin PhD (Committee Member); Nyla Heerema PhD (Committee Member) Subjects: Health Sciences; Oncology

Doctor of Philosophy, The Ohio State University, 2011, Pharmacy

Chronic lymphocytic leukemia (CLL) is the most common adult leukemia in Western world. Flavopiridol (Alvocidib, NSC 649890), as a pan cyclin-dependent kinases inhibitor (CDKI), initiates cell cycle arrest and p53-independent apoptosis through down-regulation of Mcl-1 and X-linked inactivator of apoptosis (XIAP). A novel pharmacokinetically (PK)-based dosing schedule with a 30-minute intravenous bolus loading dose (IVB) followed by a 4-hour continuous intravenous infusion (CIVI) in patients with refractory CLL produced an approximately 50% overall response rate. A major flavopiridol metabolite, flavopiridol glucuronide (flavo-G), was as also evaluated in this study. In order to fully understand the inter-individual variability between patients, a phase 1 CLL patient data set (OSU0055) was evaluated and a two-compartment flavopiridol PK model followed by first-order elimination was developed by nonlinear mixed effects modeling. Bilirubin level was shown as a significant covariate, and OATP1B1 was first time discovered having a significant correlation with flavopiridol PK parameters. A functional analysis in vitro study was done to confirm that flavopiridol and flavo-G are substrates of OATP1B1. Since cellular redox status is important on cell survival and previous studies showed that flavopiridol can induce the decrease of intracellular GSH levels in transformed cells, glutathione (GSH) level was evaluated among leukemia cell models and patient's CLL cells. The change in GSH level compared to baseline after flavopiridol treatment varied among cell models and individual patient. In order to evaluate flavo-G with flavopiridol treatment, a linked parent-metabolite population PK model was developed. This model was expanded to include a pharmacodynamic logistic-regression component linked to flavopiridol exposure level. This developing PK-PD-PG model of flavopiridol will help to characterize the factors associated with inter-individual variability in drug disposition and o (open full item for complete abstract)

Committee: Mitch A. Phelps PhD (Committee Chair); Guillaume Wientjes PhD (Committee Member); Robert Lee PhD (Committee Member) Subjects: Pharmaceuticals; Pharmacy Sciences

Master of Science, The Ohio State University, 2009, Pathology

Chronic lymphocytic leukemia (CLL) is the most common adult leukemia in the United States. There is no known cure for CLL. While biomarkers have been found to correlate with disease progression, such as CD38, IGHV, and ZAP-70, there is a need for further validation of these biomarkers as well as new biomarker discovery. In this study, publicly available gene expression data from NCBI's Gene Expression Omnibus was used to identify genes with expression correlated to ZAP-70 and CD38 mRNA expression patterns. Also utilized were vast amounts of data from the Chronic Lymphocytic Leukemia Research Consortium (CRC) to search for novel correlations between clinical markers and disease progression and treatment outcome. We found several hundred genes with expression patterns correlated to ZAP-70. We also found several clinical, genetic, biologic, and immunologic CRC data fields which were correlated significantly and at weakly to strongly associated.

Committee: KUN HUANG PhD (Advisor); PHILIP PAYNE PhD (Committee Member) Subjects: Pathology