Cancer Biology Commons^™

The Role Of Increased Matrix Metalloproteinase (Mmp14) Expression On Apoptosis Sensitivity In Human Breast Cancer Cells, Roukayah Rifai

Undergraduate Student Research Internships Conference

A member of the matrix metalloproteinase family (MMP14) plays a crucial role in extracellular matrix (ECM) remodeling, as it possesses characteristics that aid in cell proliferation and differentiation. MMP14 domains can bind to FIH-1, which is a protein that can prevent apoptosis in cells when attached to BAX in the mitochondria. This study will investigate the varying expressions of MMP14 on FIH-1 and BAX, and their effects on apoptotic sensitivity. Three cell lines with varying levels of MMP14 expression will be used: C3 (~11 fold), ΔCD (~100 fold), and C2 (~500 fold). With the overexpression of MM14 on the cell …

Kindlin-1 Is Involved In Spreading, Migration, And Protein Regulation In Epidermal Scc-13 Cells, Naomi Mishan

Electronic Thesis and Dissertation Repository

Kindlin-1 is a scaffold protein linking the cytoskeleton to the extracellular matrix. Loss of function mutations in the FERMT1 gene (encoding Kindlin-1) cause gastrointestinal and skin defects associated with increased susceptibility to aggressive epidermal squamous cell carcinoma (SCC). This study investigated the consequences of targeted FERMT1 inactivation in the SCC-13 cell line of epidermal SCC. My studies demonstrate Kindlin-1 is not essential for SCC-13 proliferation or clonogenic potential in culture. Kindlin-1 was required for cell spreading on collagen I, but not on laminin-332, and its absence enhanced SCC-13 directional migration. Finally, I identified several proteins involved in tumor formation and …

Insights Into O-Glcnac-Mediated Regulation Of Galectin Expression And Secretion In Promyelocytic Hl-60 Cells, Adam J. Mctague

Electronic Thesis and Dissertation Repository

Galectins are a family of -galactoside-binding proteins involved in cell stress responses and differentiation. Galectins are multifunctional proteins widely studied in many cell models including acute myeloid leukemia HL-60 cells where they mediate numerous intra- and extracellular functions in response to many stress-inducing stimuli. O-GlcNAcylation is a dynamic post-translational modification implicated in the regulation of many cellular diseases including cancers. The O-GlcNAc mediated expression and secretion of galectins during neutrophilic differentiation was examined in HL-60 cells. Galectin gene (LGALS), galectin protein expression, and galectin secretion were determined by RT-qPCR, immunoblotting, and ELISA, respectively. Inhibition of O-GlcNAcylation induced markers of differentiation …

The Regulation Of Pannexin1 And Pannexin2 In The Skin In Health And Disease, Rafael E. Sanchez Pupo

Electronic Thesis and Dissertation Repository

Pannexins (PANX1, 2, 3) are a family of channel-forming glycoproteins that mediate intracellular and paracrine signaling. In contrast to PANX2, PANX1 has been extensively investigated in the skin, modulating cell differentiation, wound healing, and melanoma development. PANX1 and PANX2 can co-exist in the same cell and form mixed channels where their glycosylation seems to regulate their intermixing. N-glycosylation and caspase cleavage have been proposed as modulators of the function of PANX1, but their effects on PANX2 are unknown. We explored the PANX2 expression in mouse skin and showed that a Panx2 splice variant (PANX2-202) is continuously expressed throughout aging skin. …

Inhibition Of Pannexin 1 Reduces Tumorigenic Properties Of Human Melanoma, Taylor J. Freeman

Electronic Thesis and Dissertation Repository

Pannexin 1 (PANX1) is a channel-forming glycoprotein that allows the passage of important signaling molecules, including ATP. We examined PANX1 levels in a panel of human melanomas and evaluated its potential as an effective target for melanoma therapy. We are the first to report endogenous PANX1 levels in multiple human melanoma cell lines, patient-derived melanoma biopsies, and primary melanoma cells. Treatment with two PANX1 channel blockers, Carbenoxolone (CBX) and Probenecid (PBN), on A375 and A375-MA2 melanoma cells significantly reduced cell growth and migration, and increased the production of melanin, a marker for a melanocytic-like phenotype. Daily treatment with CBX or …

Nuak1 Has Tumor Suppressive Activity In Epithelial Ovarian Cancer, Parima Saxena

Electronic Thesis and Dissertation Repository

NUAK1, a downstream substrate of the stress metabolism regulator Liver kinase B1 (LKB1), has been implicated as an oncogene and tumor suppressor, with distinct roles in cell cycle, senescence and cell adhesion. Epithelial ovarian cancer (EOC) spheroids remain dormant during intraperitoneal metastasis with reduced proliferation and metabolism to survive metabolically harsh conditions, possibly implicating a role of NUAK1 in EOC spheroid biology. I hypothesize that NUAK1 is regulated by LKB1 to promote dormancy in EOC. I demonstrate that NUAK1 expression and phosphorylation is regulated by LKB1 in EOC cell lines. NUAK1 is largely under-expressed in many established and new ascites-derived …

Mt1-Mmp Mediates The Migratory And Tumourigenic Potential Of Breast Cancer Cells Via Non-Proteolytic Mechanisms, Mario Cepeda

Electronic Thesis and Dissertation Repository

Membrane Type-1 Matrix Metalloproteinase (MT1-MMP) is a multifunctional protease that affects cell function via proteolytic and non-proteolytic mechanisms such as promoting degradation of the extracellular matrix (ECM) or augmentation of cell migration and viability, respectively. MT1-MMP has been implicated in metastatic progression ostensibly due to its ability to degrade ECM components and to allow migration of cells through the basement membrane. Despite in vitro studies demonstrating this principle, this knowledge has not translated into the use of MMP inhibitors (MMPi) that inhibit substrate catalysis as effective cancer therapeutics, or been corroborated by evidence of in vivo ECM degradation mediated by …

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 …

Inhibition Of Mt1-Mmp Proteolytic Function And Erk1/2 Signalling Influences Breast Cancer Cell Migration And Invasion Through Changes In Mmp-2 And Mmp-9 Expression, Caitlin L. Evered

Electronic Thesis and Dissertation Repository

Membrane-type 1 matrix metalloproteinase (MT1-MMP) is a multifunctional protease that invokes changes extracellularly via cleavages of ECM substrates, and intracellularly through induction of cell signalling cascades, both to influence cell behaviour and motility. The effects of MT1-MMP activation, MMP catalytic activity, and ERK1/2 signalling were examined by chemically or genetically altering each parameter. Regardless of treatment, expression of the two gelatinases, MMP-2 and -9, were always altered in an inverse relationship. This work proposes a pathway through active MT1-MMP initiation of ERK1/2 phosphorylation and subsequent targeting the NF-κB transcription factor, to ultimately influence MMP-9 expression. Modulation of MT1-MMP activation, …

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 …

Oncolytic Virus Therapy For The Treatment Of Metastatic Ovarian Cancer, Jessica Tong

Electronic Thesis and Dissertation Repository

The management of patients with epithelial ovarian cancer (EOC) faces two major challenges which standard treatments fail to effectively address: 1) Diffuse metastasis as a consequence of late stage diagnosis and 2) intra-tumoral heterogeneity, which fuels tumor evolution and drives the acquisition of chemotherapeutic resistance. In this thesis, we tested new therapeutic strategies using a 3-dimensional in vitro spheroid culture model that mimics key steps of epithelial ovarian cancer metastasis; and another model that mimics both temporal and cellular heterogeneity by establishing multiple cell lines from a single patient over the course of disease progression. Using these models, we investigated …

Characterizing The C-Terminal Region Of Human Adenovirus E1a: An Undiscovered Country, Michael J. Cohen

Electronic Thesis and Dissertation Repository

Human Adenovirus (HAdV) E1A is the first protein expressed during viral infection. The primary function of E1A is to reprogram the cell for viral replication, but it is additionally capable of transforming primary rodent cells in co-operation with other oncogenes such as HAdV E1B. Despite extensive study, little is known about the function and cellular targets of the C-terminal region of E1A. Importantly, this region is required for the transforming ability of E1A with E1B, but can also suppress transformation with Ras. Previous studies showed that interaction with the C-terminal Binding Protein (CtBP) plays a role in both functions described …

Genomic Predictors Of Drug Response To The Alpha-Specific Phosphoinositol 3-Kinase (Pi3ka-Alpha) Inhibitor Byl719 In Head And Neck Cancers, Giananthony T. Rizzo

Electronic Thesis and Dissertation Repository

PIK3CA is the only frequently mutated, druggable oncogene in head and neck squamous cell cancer (HNSCC), with PIK3CA point mutations and gene amplification rates of 17.5% and 40% respectively, with higher rates in HPV-positive disease. The objective of this research was to determine the effects of BYL719, an α-specific PI3K inhibitor in HNSCC cell lines.

All cell lines with PIK3CA hotspot point mutations or gene amplifications will be sensitive to BYL719.

Twenty-eight HNSCC cell lines were subjected to increasing concentrations of BYL719 and cell viability was measured over time. Cell lines were screened for activating PIK3CA hotspot mutations and amplifications …

Distinct Roles Of Bmp And Lkb1/Ampk Signalling Impacting Ovarian Cancer Spheroid Biology, Teresa M. Peart

Electronic Thesis and Dissertation Repository

High-grade serous (HGS) carcinoma, the most prevalent and most deadly subtype of epithelial ovarian cancer (EOC), presents unique therapeutic challenges since the majority of cases are diagnosed at advanced, metastatic stage. At this point widespread intraperitoneal metastatic lesions are numerous, which is why models that recapitulate disease dissemination are critical to uncover novel therapeutic targets. One of the initiating events in ovarian cancer metastasis is shedding from the primary tumour into the peritoneal cavity where cells must survive in suspension in order to seed secondary tumours. This non-adherent population of cells exists as multicellular aggregates, or spheroids; data from our …

Transforming Growth Factor-Beta Receptor Signalling Is Modulated By Integrin-Linked Kinase, Stellar H. Boo

Electronic Thesis and Dissertation Repository

Transforming growth factor-beta 1 (TGF-β1) modulates regeneration after injury through induction of fibroblast proliferation, migration, and differentiation into myofibroblasts. Induction of myofibroblast differentiation by TGF-β1 requires expression of integrin-linked kinase (ILK). I now show that ILK interacts with TGF-β receptor type II (TβRII) in primary dermal fibroblasts. Further, colocalization of ILK and TβRII can be observed at the cell membrane and in intracellular vesicles. The association of TβRII and ILK does not require TGF-β1 stimulation, kinase activity of TGF-β1 receptor type I or TβRII, and it does not involve interactions between ILK and focal adhesion-associated proteins. When this interaction is …

Systematic Analysis Of Residues In Conserved Region 3 Of The Human Papillomavirus 16 E7 Oncoprotein, Biljana Todorovic

Electronic Thesis and Dissertation Repository

Although remarkable biological diversity is exhibited by viruses, as obligate intracellular parasites, they rely on host cell functions. As such, viruses typically must overcome a set of host barriers that prevent infection. For human papillomaviruses (HPV) one of these barriers is the state of terminal differentiation of the host cell. For that purpose HPVs encode two major oncoproteins, E6 and E7, which combine their efforts to effectively uncouple cellular differentiation from the cell cycle arrest. The E7 proteins have no intrinsic enzymatic activity or DNA binding ability, but they bind and manipulate numerous host proteins. E7 is a modular oncoprotein …

Functional Significance Of Ilk-Elmo2 Interactions In Epidermal Keratinocytes, Ernest Ho

Electronic Thesis and Dissertation Repository

The epidermis consists of a basal layer of undifferentiated keratinocytes and multiple suprabasal layers of differentiated keratinocytes. Undifferentiated keratinocytes are adherent and highly motile, whereas differentiated keratinocytes are comparatively less motile and downregulate cell attachments to the extracellular matrix. Integrin-linked kinase (ILK) is a scaffold protein implicated in the regulation of many cellular functions in keratinocytes, including cell attachment, migration, phagocytosis, and protein trafficking. To determine the mechanisms by which ILK is involved in these processes, I sought to identify other proteins which may interact with ILK in keratinocytes. I identified Engulfment and Cell Motility 2 (ELMO2) to interact with …

Timp-2 Decreases The Invasive Potential Of Mcf-7 And Mdamb-231 Cells Independent Of Mmp Inhibition, Mario Cepeda

Electronic Thesis and Dissertation Repository

Tissue Inhibitors of Metalloproteinases (TIMPs) are the natural inhibitors of Matrix Metalloproteinases (MMPs), a family of proteins primarily responsible for Extracellular Matrix (ECM) remodeling. TIMP-2 is a special member of the TIMP family as it is both an inhibitor and promoter of MMP activity, and can also bind the cell surface and signal inside the cell to influence cell behavior. In this study, MDAMB-231 and MCF-7 breast cancer cells were treated with physiological concentration of TIMP-2, which decreased the invasive potential of both cell lines. This was independent of MMP inhibition, and instead a decrease in the expression and secretion …

The Embryonic Protein Nodal Supports Metastatic Phenotypes In Breast Cancer, Daniela F. Quail

Electronic Thesis and Dissertation Repository

Metastasis is the process by which tumour cells disseminate to distant organ sites. Aberrant expression of stem cell-associated proteins within tumours is associated with metastasis and poor patient prognosis. One example of a stem cell factor that is associated with cancer progression is Nodal, a member of the TGF-β superfamily. Nodal is normally limited to pluripotent stem cells during embryonic development, and to specialized dynamic adult tissue (such as the cycling endometrium), but is aberrantly re-expressed in multiple cancer types, including melanoma, glioma, prostate cancer, and pancreatic cancer. The central objective of this thesis is to determine the role of …