Oncology Commons^™

Interaction Of The Oncoprotein Transcription Factor Myc With Its Chromatin Cofactor Wdr5 Is Essential For Tumor Maintenance., Lance R. Thomas, Clare M. Adams, Jing Wang, April M. Weissmiller, Joy Creighton, Shelly L. Lorey, Qi Liu, Stephen W. Fesik, Christine M. Eischen, William P. Tansey

Department of Cancer Biology Faculty Papers

The oncoprotein transcription factor MYC is overexpressed in the majority of cancers. Key to its oncogenic activity is the ability of MYC to regulate gene expression patterns that drive and maintain the malignant state. MYC is also considered a validated anticancer target, but efforts to pharmacologically inhibit MYC have failed. The dependence of MYC on cofactors creates opportunities for therapeutic intervention, but for any cofactor this requires structural understanding of how the cofactor interacts with MYC, knowledge of the role it plays in MYC function, and demonstration that disrupting the cofactor interaction will cause existing cancers to regress. One cofactor …

Identification And Molecular Analysis Of Dna In Exosomes, Jena Tavormina

Dissertations & Theses (Open Access)

Exosomes are heterogeneous nanoparticles 50-150nm in diameter. Exosomes contain many functional cargo components, such as protein, DNA, and RNA. While protein and RNA exosome content has been extensively studied, very little work has been done to characterize exosomal DNA. Here, we demonstrate that exosomal DNA is heterogeneous and its packaging into exosomes is dependent on the cell of origin. Furthermore, through a rigorous assessment of various isolation methods, we identify Size Exclusion Chromatography (SEC) as the best method for the isolation of exosomal DNA for downstream applications. Additionally, we evaluate the methylation status of exosomal DNA and demonstrate that exosomal …

Identification Of Monocyte-Like Precursors Of Granulocytes In Cancer As A Mechanism For Accumulation Of Pmn-Mdscs., Jérôme Mastio, Thomas Condamine, George Dominguez, Andrew V Kossenkov, Laxminarasimha Donthireddy, Filippo Veglia, Cindy Lin, Fang Wang, Shuyu Fu, Jie Zhou, Patrick Viatour, Sergio Lavilla-Alonso, Alexander T. Polo, Evgenii N. Tcyganov, Charles Mulligan, Brian Nam, Joseph Bennett, Gregory Masters, Michael Guarino, Amit Kumar, Yulia Nefedova, Robert H. Vonderheide, Lucia R. Languino, Scott I. Abrams, Dmitry I. Gabrilovich

Department of Cancer Biology Faculty Papers

We have identified a precursor that differentiates into granulocytes in vitro and in vivo yet belongs to the monocytic lineage. We have termed these cells monocyte-like precursors of granulocytes (MLPGs). Under steady state conditions, MLPGs were absent in the spleen and barely detectable in the bone marrow (BM). In contrast, these cells significantly expanded in tumor-bearing mice and differentiated to polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs). Selective depletion of monocytic cells had no effect on the number of granulocytes in naive mice but decreased the population of PMN-MDSCs in tumor-bearing mice by 50%. The expansion of MLPGs was found to be …

Activation Of Lxrβ Inhibits Tumor Respiration And Is Synthetically Lethal With Bcl-Xl Inhibition, Trang Thi Thu Nguyen, Chiaki Tsuge Ishida, Enyuan Shang, Chang Shu, Consuelo Torrini, Yiru Zhang, Elena Bianchetti, Maria J. Sanchez-Quintero, Giulio Kleiner, Catarina M. Quinzii, Mike-Andrew Westhoff, Georg Karpel-Massler, Peter Canoll, Markus D. Siegelin

Publications and Research

Liver-X-receptor (LXR) agonists are known to bear anti-tumor activity. However, their efficacy is limited and additional insights regarding the underlying mechanism are necessary. By performing transcriptome analysis coupled with global polar metabolite screening, we show that LXR agonists, LXR623 and GW3965, enhance synergistically the anti-proliferative effect of BH3 mimetics in solid tumor malignancies, which is predominantly mediated by cell death with features of apoptosis and is rescued by exogenous cholesterol. Extracellular flux analysis and carbon tracing experiments (U-¹³C-glucose and U-¹³C-glutamine) reveal that within 5 h, activation of LXRβ results in reprogramming of tumor cell metabolism, leading …

Generation Of An Oncolytic Adenovirus Targeting The Cxcr4 And Cxcr7 Chemokine Receptors In Breast Cancer, Samia Melissa O'Bryan

LSU Doctoral Dissertations

Breast cancer is the most diagnosed cancer in women under 60 and the second most diagnosed cancer in women over 60. While treatments for localized breast cancer are quite successful with high survival rates at 99%, advanced breast cancer remains hard to treat with a nearly 75% decrease in survival. Current treatments are inefficient at treating advanced stages of breast cancer, and thus, new therapies are sorely needed to address the complexity of advanced stage breast cancer. The ideal therapy would be capable of systemic administration, targets cancer cells and spares normal tissue. Oncolytic adenovirus is an ideal therapeutic vector …

N-Glycosylation-Defective Splice Variants Of Neuropilin-1 Promote Metastasis By Activating Endosomal Signals, Xiuping Huang, Qing Ye, Min Chen, Aimin Li, Wenting Mi, Yuxin Fang, Yekaterina Y. Zaytseva, Kathleen L. O'Connor, Craig W. Vander Kooi, Side Liu, Qing-Bai She

Markey Cancer Center Faculty Publications

Neuropilin-1 (NRP1) is an essential transmembrane receptor with a variety of cellular functions. Here, we identify two human NRP1 splice variants resulting from the skipping of exon 4 and 5, respectively, in colorectal cancer (CRC). Both NRP1 variants exhibit increased endocytosis/recycling activity and decreased levels of degradation, leading to accumulation on endosomes. This increased endocytic trafficking of the two NRP1 variants, upon HGF stimulation, is due to loss of N-glycosylation at the Asn150 or Asn261 site, respectively. Moreover, these NRP1 variants enhance interactions with the Met and β1-integrin receptors, resulting in Met/β1-integrin co-internalization and co-accumulation on endosomes. This provides persistent …

The Bone Extracellular Matrix As An Ideal Milieu For Cancer Cell Metastases., Alexus D. Kolb, Karen M. Bussard

Department of Cancer Biology Faculty Papers

Bone is a preferential site for cancer metastases, including multiple myeloma, prostate, and breast cancers.The composition of bone, especially the extracellular matrix (ECM), make it an attractive site for cancer cell colonization and survival. The bone ECM is composed of living cells embedded within a matrix composed of both organic and inorganic components. Among the organic components, type I collagen provides the tensile strength of bone. Inorganic components, including hydroxyapatite crystals, are an integral component of bone and provide bone with its rigidity. Under normal circumstances, two of the main cell types in bone, the osteoblasts and osteoclasts, help to …

M6a Mrna Demethylase Fto Regulates Melanoma Tumorigenicity And Response To Anti-Pd-1 Blockade, Seungwon Yang, Jiangbo Wei, Yan-Hong Cui, Gayoung Park, Palak Shah, Yu Deng, Andrew E. Aplin, Zhike Lu, Seungmin Hwang, Chuan He, Yu-Ying He

Department of Cancer Biology Faculty Papers

Melanoma is one of the most deadly and therapy-resistant cancers. Here we show that N⁶-methyladenosine (m⁶A) mRNA demethylation by fat mass and obesity-associated protein (FTO) increases melanoma growth and decreases response to anti-PD-1 blockade immunotherapy. FTO level is increased in human melanoma and enhances melanoma tumorigenesis in mice. FTO is induced by metabolic starvation stress through the autophagy and NF-κB pathway. Knockdown of FTO increases m⁶A methylation in the critical protumorigenic melanoma cell-intrinsic genes including PD-1 (PDCD1), CXCR4, and SOX10, leading to increased RNA decay through the m⁶A reader YTHDF2. Knockdown of …

The Role Of Ros In The Progression And Treatment Of Castration-Resistant Prostate Cancer, Dannah R. Miller

Theses & Dissertations

Prostate cancer is the second leading cause of cancer-related deaths in U.S. men, primarily due to the development of castration-resistant (CR) prostate cancer (PCa), of which there are no effective treatment options. Reactive oxygen species (ROS) plays a critical role in prostate carcinogenesis, including the progression of the CR PCa phenotype. ROS regulates both cell proliferation and apoptosis; a moderate increase in ROS can promote proliferation; however, a substantial rise in ROS levels will result in apoptosis. Oxidase p66Shc is elevated in clinical PCa cells and has been associated with a metastatic phenotype of CR PCa cells, promoting PCa cell …

Differential Iron Regulatory Genetics In 2d & 3d Culture Of Breast Cancer Cells, Tyler Hanna, Suzy Torti Ph. D, Frank Torti M.D., Mph, Nicole Farra Ph. D.

Honors Scholar Theses

The iron regulatory axis has consistently been shown to be perturbed in cancer cell lines relative to non-cancerous cell lines. As cancer cells rapidly divide and grow, they require iron to fuel many intracellular processes, including DNA replication and protein synthesis. Three-dimensional cell culture is an increasingly popular method of culture that purportedly more accurately mimics the in vivo microenvironment of cancers over traditional two-dimensional culture. This project was prompted by previous lab results to investigate differential iron regulatory gene expression in 2D and 3D spheroid culture models. We replicated the findings that the gene hepcidin is induced in 3D …

Tumor-Derived Extracellular Vesicles Require Β1 Integrins To Promote Anchorage-Independent Growth., Rachel M. Derita, Aejaz Sayeed, Vaughn Garcia, Shiv Ram Krishn, Christopher D. Shields, Srawasti Sarker, Andrea Friedman, Peter Mccue, Sudheer Kumar Molugu, Ulrich Rodeck, Adam P. Dicker, Lucia R. Languino

Department of Cancer Biology Faculty Papers

The β1 integrins, known to promote cancer progression, are abundant in extracellular vesicles (EVs). We investigated whether prostate cancer (PrCa) EVs affect anchorage-independent growth and whether β1 integrins are required for this effect. Specifically using a cell-line-based genetic rescue and an in vivo PrCa model, we show that gradient-purified small EVs (sEVs) from either cancer cells or blood from tumor-bearing TRAMP (transgenic adenocarcinoma of the mouse prostate) mice promote anchorage-independent growth of PrCa cells. In contrast, sEVs from cultured PrCa cells harboring a short hairpin RNA to β1, from wild-type mice or from TRAMP mice carrying a β1 conditional ablation …

Translational Control Of Stress Induced Breast Cancer Plasticity, Michael Jewer

Electronic Thesis and Dissertation Repository

Cancer cell plasticity, whereby stem-cell-like properties are acquired in response to stress, represents a major challenge in cancer treatment. Using cell line and patient-derived xenograft (PDX) models, we demonstrate that translational reprogramming occurs in response to stresses such as hypoxia and chemotherapy which elicits stem cell properties in breast cancer. Other stresses like chemotherapy demonstrate the translational inhibition that has been well characterized as an integral hypoxic cellular response. The inhibition of translation is primarily regulated at initiation by mTOR/4E-BP1 and PERK/eIF2α signalling. We identify previously undescribed 5’ untranslated regions (5’UTRs) of plasticity-associated genes like NANOG, SNAIL and NODAL. …

Itch Nuclear Translocation And H1.2 Polyubiquitination Negatively Regulate The Dna Damage Response, Lufen Chang, Lei Shen, Hu Zhou, Jing Gao, Hangyi Pan, Li Zheng, Brian Armstrong, Yang Peng, Guang Peng, Binhua P. Zhou, Steven T. Rosen, Binghui Shen

Molecular and Cellular Biochemistry Faculty Publications

The downregulation of the DNA damage response (DDR) enables aggressive tumors to achieve uncontrolled proliferation against replication stress, but the mechanisms underlying this process in tumors are relatively complex. Here, we demonstrate a mechanism through which a distinct E3 ubiquitin ligase, ITCH, modulates DDR machinery in triple-negative breast cancer (TNBC). We found that expression of a nuclear form of ITCH was significantly increased in human TNBC cell lines and tumor specimens. Phosphorylation of ITCH at Ser257 by AKT led to the nuclear localization of ITCH and ubiquitination of H1.2. The ITCH-mediated polyubiquitination of H1.2 suppressed RNF8/RNF168-dependent formation of 53BP1 foci, …

Potential Applications Of Capsaicinoids In Small Cell Lung Cancer Therapy, Jamie Rae Friedman

Theses, Dissertations and Capstones

Lung cancer continues to be the leading cause of cancer related mortality worldwide. Lung cancer is not a single disease but an umbrella that encompasses two major classifications, nonsmall cell lung cancer (NSCLC) and small cell lung cancer (SCLC). SCLC represents about 15- 20% of all lung cancer cases and is almost exclusively diagnosed in smokers. Typically, patients will respond very well to first line treatment, but face inevitable relapse. The fact that SCLC still carries a grim 5-year survival rate of less than 5% highlights the lack of advancement in treatment options to effectively improve patient response and survival. …

Inhibition Of Cancer Stem Cells By Glycosaminoglycan Mimetics, Connor P. O'Hara

Theses and Dissertations

Connor O’Hara July 29, 2019

Inhibition of Cancer Stem Cells by Glycosaminoglycan Mimetics

In the United States cancer is the second leading cause of death, with colorectal cancer (CRC) being the third deadliest cancer and expected to cause over 51,000 fatalities in 2019 alone.¹ The current standard of care for CRC depends largely on the staging, location, and presence of metastasis.² As the tumor grows and invades nearby lymph tissue and blood vessels, CRC has the opportunity to invade not only nearby tissue but also metastasize into the liver and lung (most commonly).³ The 5-year survival rate …