Cancer Biology Commons^™

Targeting Cox-2 And Rank In Aggressive Breast Cancers: Inflammatory Breast Cancer And Triple-Negative Breast Cancer, Monica Elizabeth Reyes

Dissertations and Theses (Open Access)

Inflammatory breast cancer (IBC) and triple-negative breast cancer (TNBC) are two highly aggressive breast cancer subtypes associated with a poor outcome. Despite sensitivity to current treatment, these breast cancers subtypes have a high recurrence rate and proclivity to metastasize early. The aggressiveness of IBC and TNBC have been linked to CSCs and epithelial to mesenchymal transition (EMT), which are critical features of breast cancer progression and metastasis. The clinical challenge faced in the treatment of IBC and TNBC is finding a treatment strategy to target the cancer stem-like (CSC) population to block metastasis. Cyclooxygenase-2 (COX-2) and receptor activator of nuclear …

Strategies To Sensitize Bladder Cancer Cells To Small Molecule Inhibitors Targeting The Pi3k Pathway, Giovanni Nitti

Dissertations and Theses (Open Access)

After many years of cancer research, it is well accepted by the scientific community that the future cure for this disease lies in a personalized therapeutic approach. Anticipating therapeutic outcome based on the genetic signature of a tumor has become the new paradigm. The PI3K pathway represents an ideal target for bladder cancer, as many of the key proteins of this pathway are altered or mutated in this particular type of cancer. Several small molecule inhibitors have been developed to target this pathway, but their efficacy has been shown to be heterogeneous among different cell lines and mostly cytostatic but …

Mapping The Human Vasculature By In Vivo Phage Display, Julianna Bronk

Dissertations and Theses (Open Access)

In vivo phage display screenings by intravenous injection of a random phage-displayed peptide library allow for the selection of peptides that localize to specific vascular beds. At the University of Texas MD Anderson Cancer Center, we have had the opportunity to perform phage display screenings in cancer patients in order to select for cancer specific targets directly in humans. These targets serve to define biochemical diversity of endothelial cell surfaces and can be validated and explored towards the design of vascular-targeted pharmacology. In the most recent patient screen, samples were recovered from hepatocellular carcinoma (HCC) as well as 26 additional …

Cd56-Specific T Cells: Using Genetically Engineered T Cells To Redirect Specificity To A T Cell Expressed Antigen, Denise L. Crossland

Dissertations and Theses (Open Access)

The CD56 antigen is expressed on several deadly malignancies currently lacking long-term efficacious therapies. Chimeric antigen receptor (CAR) based immunotherapies have shown both safety and efficacy and even a curative ability in clinical trials, laying the foundation for applying CARs to new targets. Using T cells to target a T cell expressed antigen, such as CD56, seems counterintuitive in that the T cells would be susceptible to self-targeting a.k.a. fratricide. However, we expand CD56-specific CAR⁺ T cells that co-express the CD56 antigen. Since other CARs targeting T cell expressed antigens are hypothesized to be undergoing fratricide, such as the …

Tyrosine 370 Phosphorylation Of Atm Positively Regulates Dna Damage Response, Hong-Jen Lee

Dissertations and Theses (Open Access)

Ataxia telangiectasia-mutated (ATM) mediates DNA damage response by controlling irradiation (IR)-induced foci formation, cell cycle checkpoint, and apoptosis. However, how upstream signaling regulates ATM is not completely understood. Here, we show that upon IR stimulation, ATM associates with and is phosphorylated by epidermal growth factor receptor (EGFR) at Y370 at the site of double-strand breaks. Depletion of endogenous EGFR impairs ATM-mediated foci formation, homologous recombination, and DNA repair. Moreover, ATM Y370F mutant or pretreatment with an EGFR kinase inhibitor gefitinib blocks EGFR and ATM association, hinders CHK2 activation and subsequent foci formation, and increases radio-sensitivity. Thus, we reveal a critical …

Egfr Modulates Microrna Maturation In Response To Hypoxia Through Phosphorylation Of Argonaute2, Jia Shen

Dissertations and Theses (Open Access)

MicroRNAs (miRNAs) are generated by two-step processing to yield small RNAs that negatively regulate target gene expression at posttranscriptional level. Deregulation of miRNAs has been linked to diverse pathological processes, including cancer. Recent studies have also implicated miRNAs in regulatory roles to cope with a spectrum of stresses, such as hypoxia, which is frequently encountered in the poorly angiogenic core of a solid tumor. However, the upstream regulators of miRNA biogenesis machineries remain obscure, raising the question of how tumor cells efficiently coordinate and impose specificity on miRNA expression and function in response to stresses. Here, we show that EGFR, …

Brit1/Mcph1 Mediates The Dna Damage Response By Inducing P53 Stability And Promoting Atr Signaling, Edward Wang

Dissertations and Theses (Open Access)

The BRCT-repeat inhibitor of hTERT (BRIT1)/MCPH1 protein promotes the process of homologous recombination (HR) to repair DNA double strand breaks (DSBs). In response to DSBs, BRIT1 foci form at damaged sites, and recruits downstream repair proteins including 53BP1, MDC1, NBS1, and the SWI/SNF complex to the DSB region to promote DNA repair. BRIT1 copy number deficiency correlates with increased genomic instability in ovarian cancer specimens and breast cancer cell lines. Here, we propose that additional functions of BRIT1 include a direct interaction with the p53 tumor suppressor protein to promote p53 stability, and binding and recruitment of TopBP1 to sites …

Nuclear Translocation Of Met Via Internet Mechanism, Mei-Kuang Chen

Dissertations and Theses (Open Access)

MET is one of the receptor tyrosine kinases (RTKs) that are overexpressed in malignant cancer types, including breast cancer. While RTKs are traditionally known for their roles in signaling transduction from the cell surface, recent studies have provided evidence demonstrating that most of RTKs can translocate into nucleus to regulate cellular processes in response to both ligand and stress stimulation. Oxidative stress is a common stress in cancer cells due to alteration of metabolism, and constitutive oxidative stress related to reactive oxygen species (ROS) has been observed in breast cancer cells. Here, we show that hepatocyte growth factor (HGF) as …

Angiomotin Is A Novel Cadherin-11 Interacting Protein That Mediates Migration In Prostate Cancer Cells, Angelica Ortiz

Dissertations and Theses (Open Access)

Prostate cancer (PCa), the second leading cause of cancer-related deaths among men in the United States, has the proclivity to metastasize to bone resulting in sclerotic lesions. These cancer induced bone growths cause bone pain and fractures. Therefore, understanding the molecular mechanisms contributing to PCa bone metastasis is required in order to find better prognostic tools and suitable targets for metastasis treatment and/ or prevention. Previous work in our laboratory showed increased expression of cadherin-11 (Cad11), a mesenchymal cadherin, during PCa progression. Furthermore, Cad11 expression endows PCa cells with increased migratory potential and metastasis to bone. Deletion of the Cad11 …

Modulated Functions Of The Fanconi Anemia Core Complex, Yaling Huang

Dissertations and Theses (Open Access)

Cells derived from Fanconi anemia (FA) patients are characterized by hypersensitivity to DNA interstrand crosslinks (ICLs), suggesting that FA genes play a role in ICL repair. Fanconi anemia core complex (including A, B, C, E, F, G, L, FAAP20, and FAAP100) activates the Fanconi pathway by providing the essential E3 ligase activity for FANCD2 mono-ubiquitination. Previous studies suggested the existence of three protein-protein interaction groups. However, the functions of most FA core complex protein are still limited to their presence in the complex. How the spatially-defined FANCD2 ubiquitination is accomplished by the core complex remains unknown.

To elucidate the roles …

Mechanisms Underlying Distinct Egfr Versus Fgfr-3 And -1 Dependency In Human Bladder Cancer Cells, Tiewei Cheng

Dissertations and Theses (Open Access)

The epidermal growth factor receptor (EGFR) and fibroblast growth factor receptor (FGFR) are activated by gene amplification, mutation and overexpression in bladder cancer, which drives tumor development and progression. Both EGFR and FGFR inhibitors are currently being tested in clinical trials. However, bladder cancer (BC) cells show remarkably heterogeneous sensitivities to both inhibitors, and the molecular determinants of this heterogeneity are presently unclear. Therefore, in this study, using selective EGFR and FGFR inhibitors in BC cells, we demonstrated that FGFR3 and FGFR1 play largely non-overlapping roles in mediating proliferation and invasion in the distinct “epithelial” and “mesenchymal” subsets of human …

The Association Between The Il-1 Pathway, Isaac C. Wun

Dissertations and Theses (Open Access)

Cutaneous malignant melanoma (CMM) is a potentially lethal malignancy that warrants attention and further research, as it is known to that there is an increasing rate of incidence in theUnited States, and it is also known that exposure to UV light is its most crucial risk factor, and family history of melanoma is also an important risk factor. Melanoma is an aggressive and lethal cancer in humans. There are an estimated new 132,000 melanoma cases annually worldwide, and the trend has doubled in the past 20 years. However, attempts to treat melanoma have encountered considerable resistance and remained ineffective. The …

Imbalance Between Neutrophil Elastase And Elafin Promotes Breast Cancer Growth And Progression, Joseph Anthony Caruso

Dissertations and Theses (Open Access)

Elafin, an endogenous serine protease inhibitor, is a critical component of the epithelial barrier against neutrophil elastase (NE) activity. The central hypothesis examined in this dissertation was that elafin has tumor suppressive properties in breast cancer. In support of this hypothesis, immunohistochemical (IHC) analysis revealed that elafin was downregulated in the majority of invasive breast tumors and a subset of pre-invasive ductal carcinoma in situ (DCIS) compared to elafin expression in the normal mammary epithelium. To understand the role of elafin in the mammary epithelium and the impetus for its downregulation during breast tumorigenesis, primary and immortalized human mammary epithelial …

Role Of Talin1 Phosphorylation In Beta1 Integrin Activation And Prostate Cancer Metastasis, Jung-Kang Jin

Dissertations and Theses (Open Access)

Talins are adaptor proteins that regulate focal adhesion signaling by conjugating integrins to the cytoskeleton. Talins directly bind and activate integrins but the mechanism by which this occurs is unknown. As integrin activation and overexpression of talins promote prostate cancer metastasis, understanding the mechanism by which talins activate integrins will better elucidate their roles in Prostate cancer metastasis. Phosphorylation of talins on serine 425 has been associated with β1 integrin functions. Work in this dissertation tested the hypothesis that increased talin1 S425 phosphorylation was required for β1 integrin activation and promotion of prostate cancer metastasis.

I first used shRNA to …

Metadherin Functions As A Laminin Receptor That Is Essential For Metastasis And Is Associated With Poor Survival In Osteosarcoma, Limin Zhu

Dissertations and Theses (Open Access)

Osteosarcoma is a highly invasive bone malignancy in which metastasis accounts for the vast majority of death and morbidity in patients. Understanding the mechanisms controlling metastasis is essential for improving patient survival in this disease. In order to improve the clinical outcomes for patients with poor prognosis, it is urgent to find new therapeutic targets to block metastasis in this disease. Recent studies have shown that Metadherin (MTDH) plays an essential role in mediating tumorigenesis and metastasis in a variety of human cancers. Our study assessed the role of MTDH in osteosarcoma metastasis and elucidated the mechanisms underlying its metastasis-promoting …

Anti-Insulin Resistance Treatments Suppress Her2+ Breast Cancer Growth Via Altering Metabolism, Ping-Chieh Chou

Dissertations and Theses (Open Access)

Epidemiological studies have identified that type 2 diabetes mellitus (DM2) is a significant risk factor for carcinogenesis and cancer death, including breast cancer. Our previous finding in patients showed that anti-insulin resistance treatments are associated with improved HER2⁺ breast cancer survival of diabetic women. However, there were no transgenic mouse models to study the correlation and explain the detailed mechanism. We generated a mouse model of HER2⁺ breast cancer with DM2 by crossing leptin receptor point mutation (Lepr ^db/+) and MMTV-ErbB2 (neu) mice. The MMTV-ErbB2/Lepr ^db/db mice had a poor survival rate compared …

Diabetes And Obesity Induce Transcriptomic And Metabolomic Changes Enhancing Pancreatic Cancer Aggressiveness, Guermarie Velázquez Torres

Dissertations and Theses (Open Access)

Pancreatic cancer is one of the most aggressive types of cancer, with poor prognosis that lacks effective diagnostic markers and therapies. It is expected that in 2014 the incidence and the mortality of pancreatic cancer in the United States will be 46,420 and 39,590 respectively. Diabetes and obesity are modifiable risk factors associated with accelerated pancreatic carcinogenesis and tumor progression, but the biological mechanisms are not completely understood. The purpose of this study is to demonstrate direct evidence for the mechanisms mediating these epidemiologic phenomena. Our hypothesis is that obesity and diabetes mellitus type 2 (DM2) accelerate pancreatic cancer and …

Car-Modified T Cells Capable Of Distinguishing Normal Cells From Malignant Cells, Hillary G. Caruso

Dissertations and Theses (Open Access)

T cells can be redirected to target tumor-associated antigen (TAA) by genetic modification to express a chimeric antigen receptor (CAR), which fuses the specificity derived from an antibody to T-cell activation domains to result in lysis of TAA-expressing cells. Due to the potential for on-target, off-tissue toxicity, CAR⁺ T-cell therapy is currently limited to unique or lineage-restricted TAAs. Glioblastoma, a grade IV brain malignancy, overexpresses epidermal growth factor receptor (EGFR) in 40-50% of patients. EGFR also has widespread normal tissue expression. To target EGFR on glioblastoma while reducing the potential for normal tissue toxicity, EGFR-specific CAR generated from cetuximab, …

The Regulation Of Microrna Biogenesis By Ribosome-Interacting Proteins, Brian Pickering

Dissertations and Theses (Open Access)

MicroRNA (miRNA) are small, non-coding RNAs that affect gene expression through degradation of complementary mRNA targets or inhibition of translation. As they affect approximately 50% of all cellular processes, miRNA are tightly regulated by the cell through transcriptional and post-transcriptional mechanisms. Transcribed miRNA are capped and polyadenylated (referred to as pri-miRNA) which are cleaved by Drosha and DGCR8 to generate 60-90 nucleotide precursor miRNA. The precursors are cleaved again by Dicer and loaded into the RNA-induced silencing complex (RISC) of which Argonaute 2 is the functional component. Many of the proteins involved in miRNA biogenesis share a common role in …

Regulation Of Mammary Gland Development And Tumorigenesis By 14-3-3 Zeta, Sumaiyah Rehman

Dissertations and Theses (Open Access)

Signaling pathways that play critical roles in organ development are often aberrantly regulated during cancer initiation and progression. 14-3-3z is overexpressed in more than 40% of breast cancers and is associated with poor patient prognosis. Therefore, the function of 14-3-3z in cancer and normal mammary gland development was investigated utilizing multiple in vivo and in vitro approaches. 14-3-3z is a chaperone protein that interacts with a multitude of oncogenes and tumor suppressor genes, thereby functioning as a critical node in multiple oncogenic signaling networks. Mammary gland-specific 14-3-3z transgenic mouse models showed that 14-3-3z overexpression was sufficient to induce mammary tumorigenesis. …

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

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

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 …

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

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. Moreover, …

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

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). …

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

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 of this …

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

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

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 signaling …

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

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 …

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

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, …

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

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 …