Life Sciences Commons^™

The Role Of Reactive Oxygen Species In The Accumulation Of Driver Mutations In B Cell Acute Lymphoblastic Leukemia, Mia P. Sams

Electronic Thesis and Dissertation Repository

B cell acute lymphoblastic leukemia (B-ALL) is the most prevalent type of cancer in young children and is associated with recurrent mutations and high levels of reactive oxygen species (ROS). The antioxidant N-acetylcysteine was tested for its ability to prolong lifespan of a mouse model of B-ALL and reduce frequency of mutations. Mice treated with 1g/L of N-acetylcysteine in drinking water were found to have delayed onset of B-ALL at 11 weeks of age and changes in gene expression relating to B cell development, calcium-apoptosis signaling, and pathways in cancer, although no differences in lifespan were observed. Tumours from treated …

Metabolic Reprogramming By Dna Tumour Viruses, Martin Prusinkiewicz

Electronic Thesis and Dissertation Repository

Viruses are the etiological agents of approximately 12% of human cancers. However, only a subset of viral infections eventually progress to cancer. As obligate intracellular parasites, viruses create a host-cell environment that is amenable to virus replication. These changes to host-cell processes during infection are enacted by virally-encoded proteins that act as molecular hubs. When these processes intersect with pathways that encourage the development of cancer, such as the p53 tumour suppressor pathway, these virally-encoded molecular hub proteins function as viral oncoproteins. One major requirement of both virus infected cells and rapidly growing cancer cells is an altered metabolism that …

Hpv Mediated Antagonism Of The Il-18 Proinflammatory Pathway In Head And Neck Cancer, Wyatt W. Anderson

Electronic Thesis and Dissertation Repository

In this thesis, I examined the effect of human papillomavirus (HPV) on the proinflammatory IL-18 cytokine pathway in head and neck cancers. I investigated the expression and methylation of genes associated with this pathway using The Cancer Genome Atlas (TCGA) data. In HPV+ cancers, IL18, CASP1, and AIM2 were downregulated, while IL18BP was upregulated compared to HPV- cancers and adjacent non-cancerous tissues, and IL18’s promoter was significantly more methylated. I compared HPV+ and HPV- head and neck cancer cell lines for expression of RNA and protein levels of IL-18 and IL-18BP by qPCR, western blot, and ELISA. IL-18 …

Exploiting The Immunomodulatory Potentials Of Inkt Cells In Sepsis And Cancer., Joshua Choi

Electronic Thesis and Dissertation Repository

Invariant natural killer T (iNKT) cells are a unique unconventional T cell subset that recognize glycolipids presented by CD1d expressing cells. The prototypical glycolipid agonist of iNKT cells, α-Galactosylceramide (α-GalCer), can induce the rapid release of an arsenal of cytotoxic effector molecules and enormous amounts of immunomodulatory cytokines as early as two hours after activation. In addition to α-GalCer, various glycolipid agonists are available that allow for specific, in vivo targeting of iNKT cells, and can exert divergent T-helper (T_H)1 and/or T_H2 immune responses. Therefore, the type of response instigated by iNKT cells can profoundly influence …

B Cell Acute Lymphoblastic Leukemia Is Driven By Activating Janus Kinase Mutations Cooperating With Spi1 And Spib Deletions In A Murine Model, Michelle Lim

Electronic Thesis and Dissertation Repository

B cell acute lymphoblastic leukemia (B-ALL) is caused by genetic lesions in developing B cells that function as drivers for accumulation of additional mutations in an evolutionary selection process. We investigated secondary drivers of leukemogenesis and their mechanism(s) of arising in a mouse model of B-ALL driven by PU.1/Spi-B deletion (Mb1-CreDPB). Whole exome sequencing revealed recurrent mutations in Jak3 (encoding Janus Kinase 3) and Jak1. Mutations with high variant allele frequency (VAF) were dominated by C->T transition mutations that were compatible with AID, whereas the majority of mutations, with low VAF, were dominated by C->A transversions associated with …

The Role Of Thymine-Dna Glycosylase In Transcriptional Regulation, Bart Kolendowski

Electronic Thesis and Dissertation Repository

Precise control over transcriptional regulation is required for normal cell function. Errors in transcriptional regulation underpin many diseases including cancer. Thymine DNA Glycosylase (TDG) is a base excision repair protein and a coregulator that has been implicated in a diverse set of fundamental biological processes including embryonic development, nuclear receptor signaling and Wnt signaling. Importantly, TDG has been shown to play an important role in transcriptional regulation in a wide variety of systems. Details surrounding the mechanism through which TDG acts remain unclear. In this thesis we explore the role of TDG in Estrogen Receptor (ER)-dependent signaling and in cellular …

Role Of High Molecular Weight Hyaluronan In Ultraviolet B Light-Induced Transformation, Katelyn Cousteils

Electronic Thesis and Dissertation Repository

Keratinocyte carcinomas (KCs) are the most common cancers globally. Ultraviolet light is the key risk factor for these cancers but sunscreen has proven ineffective in their prevention, indicating a need for new prophylactic agents. Chronic elevation of high molecular weight (HMW) tissue hyaluronan (HA) in skin is linked to tumor resistance in the naked mole rat. To directly assess the role of this polysaccharide in resistance to keratinocyte tumors, a HMW HA phosphatidylethanolamine (HA-PE) formulation that penetrates skin and accumulates as coats around keratinocytes was prepared. The tumor resistance properties of the HA-PE formulation were tested in a mouse model …

Characterization Of The Catalytic Ck2 Subunits With Substitutions At Residues Involved In Inhibitor Binding, Paul Desormeaux

Electronic Thesis and Dissertation Repository

CK2 is a constitutively active, ubiquitously expressed and pleiotropic serine/threonine protein kinase that is implicated in many cellular functions including tumorigenesis. CK2 has two catalytic subunits, CK2a and CK2a’, that carry out its function in the cell. Previous studies have indicated that inhibitor-refractory mutants have been effective in recovering residual CK2 activity, in the presence of inhibitors, when compared to wild type CK2. Based on these observations, inhibitor-refractory mutants were created for both CK2a and CK2a’ and tested with various concentrations with two CK2-specific inhibitors, CX-4945 and inhibitor VIII. The CK2a triple mutant (V66A/I174A/H160D) was tested in inducible U2OS Flp-In …

Characterization Of Numb As A Regulator Of Anaplastic Lymphoma Kinase, Ran Wei

Electronic Thesis and Dissertation Repository

Cellular events rely on protein-protein interactions that are often mediated by modular domains which recognize particular sequence motifs in binding partners. The NUMB protein is the first described cell fate determinant and multifaceted adaptor that is involved in a wide variety of cellular events. NUMB mainly mediates protein interactions via its modular PTB domain. Here we present a systematic investigation of the NUMB-PTB interactome by employing an integrative strategy combining both protein and peptide arrays. We profiled NUMB-PTB binding specificity and interacting proteins genome-wide. The receptor tyrosine kinases (RTKs) are found highly enriched in the interactome, raising the possibility that …

Atrx Loss-Of-Function In Mouse Neuroprogenitor Cells As A Model Of Early Events In Gliomagenesis, Hannah E. Goldberg

Electronic Thesis and Dissertation Repository

ATRX is a chromatin remodeling protein important for neural development, and ATRX inactivation leads to genomic instability, mitotic defects and TP53-mediated apoptosis. In the last few years, ATRX mutations were identified in a large proportion of paediatric and adult gliomas that often coincide with mutations in the tumor suppressor TP53. The present work shows that combinatorial loss of ATRX and TP53 function in vitro causes genomic instability while improving cell viability, identifying potential early events in gliomagenesis. Furthermore, several gene transcripts associated with glioma development and known oncogenic pathways were significantly upregulated in the Atrx-null neonatal mouse forebrain. …

Sirna Targeting Of Thymidylate Synthase, Thymidine Kinase 1 And Thymidine Kinase 2 As An Anticancer Therapy: A Combinatorial Rnai Approach, Christine Di Cresce

Electronic Thesis and Dissertation Repository

Thymidylate synthase (TS) is the only de novo source of thymidylate (dTMP) for DNA synthesis and repair. Drugs targeting TS protein are a mainstay in cancer treatment but off-target effects and toxicity limit their use. Cytosolic thymidine kinase (TK1) and mitochondrial thymidine kinase (TK2) contribute to an alternative dTMP-producing pathway, by salvaging thymidine from the tumour milieu, and may modulate resistance to TS-targeting drugs. We have previously shown that TS antisense molecules (oligodeoxynucleotides, ODNs, and small interfering siRNA, siRNA) sensitize tumour cells, both in vitro and in vivo, to TS targeting drugs. As both TS and TKs contribute to cellular …

Characterization Of A Tumour Suppressor Function Of Ranbpm, Elnaz Atabakhsh

Electronic Thesis and Dissertation Repository

Ran-binding protein M (RanBPM) is an evolutionarily conserved nucleocytosolic protein that has been proposed to regulate various cellular processes, including protein stability, gene expression, receptor-mediated signalling pathways, cell adhesion, development, and apoptosis. Despite the multitude of functions attributed to RanBPM however, little is known regarding the precise mechanisms by which RanBPM executes these cellular roles. In this work, we seek to address this matter by describing functions for RanBPM in the regulation of apoptotic and pro-survival signalling pathways, and in cellular transformation.

We first identify RanBPM as a pro-apoptotic protein that regulates the activation of the intrinsic apoptotic signalling pathway …