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Articles 1 - 17 of 17

Full-Text Articles in Cancer Biology

Ezh2 T416 Phosphorylation Enhances Breast Cancer Tumorigenesis, Adam M. Labaff, Adam M. Labaff Dec 2013

Ezh2 T416 Phosphorylation Enhances Breast Cancer Tumorigenesis, Adam M. Labaff, Adam M. Labaff

UT GSBS Dissertations and Theses (Open Access)

Enhancer of zeste homologue 2 (EZH2) is the catalytic subunit of Polycomb repressive complex 2 (PRC2) and catalyzes the trimethylation of histone H3 on lysine 27 (H3K27Me3), to repress gene transcription. Many types of cancer stem and progenitor cells, including breast, have demonstrated EZH2 to be fundamental in the biology and promoting the expansion of their cellular populations. How EZH2 regulates each of these respective tumor initiating cells (TICs) populations has been studied, but the signaling transduction mechanisms that regulate EZH2 in these TIC populations is yet to be elucidated. Phosphorylation of EZH2 by cyclin dependent kinases (CDK) has been ...


Investigating Apoptosis Pathway In Chronic Lymphocytic Leukemia: Stromal Influence And Therapeutic Activation, Viralkumar M. Patel Dec 2013

Investigating Apoptosis Pathway In Chronic Lymphocytic Leukemia: Stromal Influence And Therapeutic Activation, Viralkumar M. Patel

UT GSBS Dissertations and Theses (Open Access)

Chronic lymphocytic leukemia (CLL) is a B-cell malignancy. High levels of Bcl-2 and IAP family proteins are responsible for apoptotic-resistance and accumulation of mature CLL lymphocytes in bone-marrow, lymph nodes and peripheral blood. Besides pro-survival proteins, supporting stromal cells as well as soluble factors in the microenvironment of bone-marrow and lymph nodes provide survival advantage to CLL leukemic cells.

Though the stromal – leukemia cell interactions has been studied extensively, in-depth-knowledge on the regulation of apoptotic pathway proteins in the context of microenvironment is still limited. To address this, the first part of our study focused on comprehensive analysis of 93 ...


C-Jun N-Terminal Kinases Regulate Adenovirus-Mediated Autophagy And Antigen Presentation, Sarah R. Klein Dec 2013

C-Jun N-Terminal Kinases Regulate Adenovirus-Mediated Autophagy And Antigen Presentation, Sarah R. Klein

UT GSBS Dissertations and Theses (Open Access)

Targeted immunotherapy with recombinant, oncolytic adenoviruses is under investigation for the treatment of cancer. Evidence indicates adenoviruses induce autophagy that is required for oncolysis, but the molecular regulation of autophagy in infected cells remains under investigation. Our data suggested the canonical pathway regulating starvation-induced autophagy was not implemented in adenovirus-induced autophagy; however, adenovirus infection triggered phosphorylation of c-Jun N-terminal kinases (JNK) that was essential for autophagy. Adenoviral replication within the host cell elicited JNK pathway activation leading to B cell lymphoma-2 (Bcl-2) phosphorylation. JNK-dependent Bcl-2 phosphorylation stimulated the dissociation of Bcl-2/beclin 1 heterodimers, enabling beclin 1 to initiate autophagy ...


T-Cell Treatments For Solid And Hematological Tumors, Drew C. Deniger Aug 2013

T-Cell Treatments For Solid And Hematological Tumors, Drew C. Deniger

UT GSBS Dissertations and Theses (Open Access)

Cell-based therapies have demonstrated potency and efficacy as cancer treatment modalities. T cells can be dichotomized by their T cell receptor (TCR) complexes where alpha/beta T cells (95% of T cells) and gamma/delta T cells (+T cells proliferated to clinically significant numbers and ROR1+ tumor cells were effectively targeted and killed by both ROR1-specific CAR+ T cell populations, although ROR1RCD137 were superior to ROR1RCD28 in clearance of leukemia xenografts in vivo. The second specific aim focused on generating bi-specific CD19-specific CAR+ gamma/delta T cells with polyclonal TCRgamma/delta repertoire on CD19+ artificial antigen presenting cells (aAPC). Enhanced ...


Characterization Of Jak, Stat, And Src Interactions In Head And Neck Squamous Cell Carcinoma, Reshma Jaseja, Reshma Jaseja Aug 2013

Characterization Of Jak, Stat, And Src Interactions In Head And Neck Squamous Cell Carcinoma, Reshma Jaseja, Reshma Jaseja

UT GSBS Dissertations and Theses (Open Access)

Recurrence of Head and Neck Squamous Cell Carcinoma (HNSCC) is common; thus, it is essential to improve the effectiveness and reduce toxicity of current treatments. Proteins in the Src/Jak/STAT pathway represent potential therapeutic targets, as this pathway is hyperactive in HNSCC and it has roles in cell migration, metastasis, proliferation, survival, and angiogenesis. During short-term Src inhibition, Janus kinase (Jak) 2, and signal transducer and activator of transcription (STAT) 3 and STAT5 are dephosphorylated and inactivated. Following sustained Src inhibition, STAT5 remains inactive, but Jak2 and STAT3 are reactivated following their early inhibition. To further characterize the mechanism ...


A Genomic Approach To Identify The Notch Pathway As A Putative Tumor Suppressor In Endometrial Cancer, Rajshi Gandhi Aug 2013

A Genomic Approach To Identify The Notch Pathway As A Putative Tumor Suppressor In Endometrial Cancer, Rajshi Gandhi

UT GSBS Dissertations and Theses (Open Access)

Endometrial cancer is the most common gynecological malignancy and the fourth most frequently diagnosed cancer among women. The molecular changes that distinguish normal endometrium from endometrial carcinoma are not thoroughly understood. Identification of these changes could potentially aid in identifying at-risk women who are especially prone to develop endometrial cancer, such as obese women and women with Lynch Syndrome.

A microarray analysis was performed using normal endometrium from thin and obese women and cancerous endometrium from obese women. We validated the differential expression of ten genes whose expression was significantly up-regulated or down-regulated using qRT-PCR. All of the genes had ...


The Role Of K63-Linked Ubiquitination Cycles In Akt Kinase Activation, Wei-Lei Yang Aug 2013

The Role Of K63-Linked Ubiquitination Cycles In Akt Kinase Activation, Wei-Lei Yang

UT GSBS Dissertations and Theses (Open Access)

Akt (also known as protein kinase B) serves a central regulator in PI3K/Akt signaling pathways to regulate numerous physiological functions including cell proliferation, survival and metabolism. Akt activation requires the binding of Akt to phospholipid PIP3 on the plasma membrane and subsequent phosphorylation of Akt by its kinases. Growth factor-mediated membrane recruitment of Akt is a crucial step for Akt activation. However, the mechanism of Akt membrane translocation is unclear. Protein ubiquitination is a significant posttranslational modification that controls many biological functions such as protein trafficking and signaling activation. Therefore, we hypothesize that ubiquitination may be involved in Akt ...


The Role Of Nucleolin In B-Cell Lymphomas And Fas-Mediated Apoptotic Signaling, Jillian F. Wise May 2013

The Role Of Nucleolin In B-Cell Lymphomas And Fas-Mediated Apoptotic Signaling, Jillian F. Wise

UT GSBS Dissertations and Theses (Open Access)

The death receptor Fas has a key role in mediating homeostasis, elimination of defective cells and more recently implicated in cancer promotion. Many effective anti-cancer therapies depend on Fas-mediated apoptosis to eradicate tumor cells and ineffective Fas-apoptotic signaling is a basis for primary as well as acquired resistance to chemotherapy. We hypothesized that Fas is subjected to direct regulation by inhibitory proteins attained by cancer cells. To screen for potential binding modulators of Fas, we analyzed lymphoma cells for Fas binding proteins. This purification scheme identified high scoring peptides derived from nucleolin, a nuclear protein known to be overexpressed in ...


Targeting Histone Deacetylases (Hdac) For The Treatment Of Soft Tissue Sarcoma, Gonzalo Lopez May 2013

Targeting Histone Deacetylases (Hdac) For The Treatment Of Soft Tissue Sarcoma, Gonzalo Lopez

UT GSBS Dissertations and Theses (Open Access)

Targeting Histone deacetylases (HDAC) for the treatment of genetically complex soft tissue sarcoma

Histone deactylase inhibitors (HDACi) are a new class of anticancer therapeutics; however, little is known about HDACi or the individual contribution of HDAC isoform activity in soft tissue sarcoma (STS). We investigated the potential efficacy of HDACi as monotherapy and in combination with chemotherapy in a panel of genetically complex STS. We found that HDACi combined with chemotherapy significantly induced anti-STS effects in vitro and in vivo. We then focused our study of HDACi in malignant peripheral nerve sheath tumor (MPNST), a subtype of highly aggressive, therapeutically ...


The Role Of Type I Insulin-Like Growth Factor Receptor Signaling In Breast Cancer Brain Metastasis, Sandra M. Saldana May 2013

The Role Of Type I Insulin-Like Growth Factor Receptor Signaling In Breast Cancer Brain Metastasis, Sandra M. Saldana

UT GSBS Dissertations and Theses (Open Access)

Brain metastasis is a common cause of mortality in cancer patients. Approximately 20-30% of breast cancer patients acquire brain metastasis, yet potential therapeutic targets remain largely unknown. The type I insulin-like growth factor receptor (IGF- IR) is known to play a role in the progression of breast cancer and is currently being investigated in the clinical setting for various types of cancer. The present study demonstrates that the IGF-IR signaling axis is constitutively active in brain-seeking sublines of breast cancer cells, driving an increase in in vitro metastatic properties. We demonstrate that IGF-IR signaling is activated in an autocrine manner ...


Oxidative Stress Based Strategies For Enhancing The Efficacy Of Histone Deacetylase Inhibitors (Hdaci), Nilsa Rivera-Del Valle May 2013

Oxidative Stress Based Strategies For Enhancing The Efficacy Of Histone Deacetylase Inhibitors (Hdaci), Nilsa Rivera-Del Valle

UT GSBS Dissertations and Theses (Open Access)

Histone deacetylase inhibitors (HDACi) are anti-cancer drugs that primarily act upon acetylation of histones, however they also increase levels of intracellular reactive oxygen species (ROS). We hypothesized that agents that cause oxidative stress might enhance the efficacy of HDACi. To test this hypothesis, we treated acute lymphocytic leukemia cells (ALL) with HDACi and adaphostin (ROS generating agent). The combination of two different HDACi (vorinostat or entinostat) with adaphostin synergistically induced apoptosis in ALL. This synergistic effect was blocked when cells were pre-treated with the caspase-9 inhibitor, LEHD. In addition, we showed that loss of the mitochondrial membrane potential is the ...


Mechanisms Underlying The Heterogeneous Sensitivities Of Cancer Cells To Proteasome Inhibitors, Matthew C. White May 2013

Mechanisms Underlying The Heterogeneous Sensitivities Of Cancer Cells To Proteasome Inhibitors, Matthew C. White

UT GSBS Dissertations and Theses (Open Access)

The mechanisms underlying cellular response to proteasome inhibitors have not been clearly elucidated in solid tumor models. Evidence suggests that the ability of a cell to manage the amount of proteotoxic stress following proteasome inhibition dictates survival. In this study using the FDA-approved proteasome inhibitor bortezomib (Velcade®) in solid tumor cells, we demonstrated that perhaps the most critical response to proteasome inhibition is repression of global protein synthesis by phosphorylation of the eukaryotic initiation factor 2-α subunit (eIF2α). In a panel of 10 distinct human pancreatic cancer cells, we showed marked heterogeneity in the ability of cancer cells to induce ...


The P63 Isoform ∆Np63Α Inhibits Epithelial – Mesenchymal Transition By Promoting The Expression Of Mir-205 In Human Bladder Cancer Cells, Mai Tran May 2013

The P63 Isoform ∆Np63Α Inhibits Epithelial – Mesenchymal Transition By Promoting The Expression Of Mir-205 In Human Bladder Cancer Cells, Mai Tran

UT GSBS Dissertations and Theses (Open Access)

p63, a p53 family member, is a transcription factor that has complex roles in cancer. This study focuses on the role of the ∆Np63α isoform in bladder cancer (BC). Epithelial – mesenchymal transition (EMT) is a physiological process that plays an important part in metastasis and drug resistance. At the molecular level, EMT is characterized by the loss of the epithelial marker E-cadherin, and the acquisition of the transcriptional repressors of E-cadherin (ZEB1, ZEB2, TWIST, SNAI1 and SNAI2). Recent publications highlight the role of microRNAs belonging to the miR-200 family and miR-205 in preventing EMT through suppression of ZEB1 and ZEB2 ...


Galectin-3 Enhances The Malignant Melanoma Phenotype By Regulating Autotaxin, Russell R. Braeuer May 2013

Galectin-3 Enhances The Malignant Melanoma Phenotype By Regulating Autotaxin, Russell R. Braeuer

UT GSBS Dissertations and Theses (Open Access)

In melanoma patient specimens and cell lines, the over expression of galectin-3 is associated with disease progression and metastatic potential. Herein, we have sought out to determine whether galectin-3 affects the malignant melanoma phenotype by regulating downstream target genes. To that end, galectin-3 was stably silenced by utilizing the lentivirus-incorporated small hairpin RNA in two metastatic melanoma cell lines, WM2664 and A375SM, and subjected to gene expression microarray analysis. We identified and validated the lysophospholipase D enzyme, autotaxin, a promoter of migration, invasion, and tumorigenesis, to be down regulated after silencing galectin-3. Silencing galectin-3 significantly reduced the promoter activity of ...


Acceleration Of The Panin Development In Mice Expressing Oncogenic K-Ras Due To A High Fat Diet, Bincy Philip May 2013

Acceleration Of The Panin Development In Mice Expressing Oncogenic K-Ras Due To A High Fat Diet, Bincy Philip

UT GSBS Dissertations and Theses (Open Access)

Obesity is postulated to be one of the major risk factors for pancreatic cancer, and recently it was indicated that an elevated body mass index (BMI correlates strongly with a decrease in patient survival. Despite the evident relationship, the molecular mechanisms involved are unclear. Oncogenic mutation of K-Ras is found early and is universal in pancreatic cancer. Extensive evidence indicates oncogenic K-Ras is not entirely active and it requires a triggering event to surpass the activity of Ras beyond the threshold necessary for a Ras-inflammation feed-forward loop. We hypothesize that high fat intake induces a persistent low level inflammatory response ...


Characterization Of Differentiation And Prognostic Biomarkers On Cd8+ Tumor-Infiltrating Lymphocytes In Metastatic Melanoma, Richard C. Wu May 2013

Characterization Of Differentiation And Prognostic Biomarkers On Cd8+ Tumor-Infiltrating Lymphocytes In Metastatic Melanoma, Richard C. Wu

UT GSBS Dissertations and Theses (Open Access)

CD8+ cytotoxic T lymphocytes (CTL) frequently infiltrate tumors, yet most melanoma patients fail to undergo tumor regression. We studied the differentiation of the CD8+ tumor-infiltrating lymphocytes (TIL) from 44 metastatic melanoma patients using known T-cell differentiation markers. We also compared CD8+ TIL against the T cells from matched melanoma patients’ peripheral blood. We discovered a novel subset of CD8+ TIL co-expressing early-differentiation markers, CD27, CD28, and a late/senescent CTL differentiation marker, CD57. This CD8+CD57+ TIL expressed a cytolytic enzyme, granzyme B (GB), yet did not express another cytolytic pore-forming molecule, perforin (Perf). In contrast, the CD8+CD57+ T ...


Investigating The Roles Of The P63 Isoforms In The Microrna Biogenesis Pathway, Deepavali Chakravarti May 2013

Investigating The Roles Of The P63 Isoforms In The Microrna Biogenesis Pathway, Deepavali Chakravarti

UT GSBS Dissertations and Theses (Open Access)

MicroRNAs play roles in various biological processes like development, tumorigenesis, metastasis and pluripotency. My thesis work has demonstrated roles for p63, a p53 family member, in the upstream regulation of microRNA biogenesis. The p63 gene has a complex gene structure and has multiple isoforms. The TAp63 isoforms contain an acidic transcription activation domain. The ΔNp63 isoforms, lack the TA domain, but have a proline rich region critical for gene transactivation. To understand the functions of these isoforms, the Flores lab generated TAp63 and ΔNp63 conditional knock out mice. Using these mice and tissues and cells from these mice we have ...