Cancer Biology Commons^™

Pi3kδ Inhibition Alters Cd8 T Cell Differentiation And Reprograms The Tumor Microenvironment Following Adoptive Immunotherapy, Alexandrea Joy Turnquist

Dartmouth College Ph.D Dissertations

T cell exhaustion remains a significant barrier to effective adoptive cell therapy in solid tumors. Here, we demonstrate that in vitro treatment with the PI3Kδ inhibitor CAL-101 generates T cells with enhanced stemness and metabolic fitness, though the stemness of these cells is not dependent on HIF-1α -dependent mechanisms. These cells show increased mitochondrial dependence and spare respiratory capacity while maintaining normal basal metabolism. Under chronic antigen stimulation, CAL-101-treated T cells, including human T cells, resist terminal exhaustion and maintain stem-like properties. Using single-cell RNA sequencing and spatial transcriptomics of B16 melanoma tumors, we found that CAL-101-treated T cells preferentially …

Immune Suppression And Epigenetic Reprogramming In Epithelial-Mesenchymal Transition, Hanxu Lu

Dartmouth College Ph.D Dissertations

Epithelial-mesenchymal transition (EMT) is increasingly recognized as a dynamic spectrum of cellular programthat contributes to tumor progression, metastasis, and therapeutic resistance. Rather than existing as discrete epithelial or mesenchymal phenotypes, tumor cells undergo intermediate EMT states in which epithelial and mesenchymal features are partially and variably expressed. In this thesis, I studied EMT state heterogeneity through two complementary and integrated dimensions: tumor-immune interactions and the dynamic remodeling of epigenetic programs across the EMT spectrum. Using a clonal EMT model derived from the murine triple-negative 4T1 mammary carcinoma cell line, including epithelial, intermediate, and mesenchymal states that are stably maintained in …

Novel Combination Therapies For Estrogen Receptor-Positive Breast Cancer Driven By Rational Molecular Mechanisms, Anneka Lila Johnson

Dartmouth College Ph.D Dissertations

Breast cancer (BC) is the most common non-keratinocyte cancer diagnosed in women in the United States with approximately 300,000 new cases diagnosed each year. Despite a myriad of treatment options, BC remains the second-most deadly cancer. Estrogen receptor-positive (ER+) BC comprises 60-70% of BC diagnoses and is treated with endocrine therapies that limit ER signaling. Despite endocrine therapy options, ~1/3 of patients experience recurrence within 10-20 years of diagnosis. Novel therapeutic strategies are required to limit BC recurrence-related morbidity and mortality.

Radiotherapy is used as an adjuvant treatment for ER+ BC patients prior to the use of endocrine therapy. Radiation …

Combination Therapy Of Ido1 Inhibition And Anti-Pd1 Mediates Anti-Tumor Immunity By Promoting Memory Immunity Development And Cytotoxicity Of Γδ T And Nk Cells Via Il-2 Signaling And By Overcoming Pro-Tumor Effects Of Tgf-Β Signaling, Hyuk Jee

Dartmouth College Master’s Theses

Cutaneous melanoma is the most aggressive form of skin cancer even though it takes only about 1% of all skin cancers. Even among all cutaneous melanomas, NRAS-mutant melanoma is more aggressive than any other, and about 10-25% of all cutaneous melanoma cases have mutations in NRAS. NRAS is a member of the RAS family of proto-oncogenic GTPase proteins, and it plays a key role in signal transduction pathways responsible for cellular survival, proliferation, and metabolism. Immunotherapy is the first line of defense against NRAS-mutant melanoma because, despite tremendous efforts made for decades, it has not been successful to develop small …

Identification And Therapeutic Targeting Of Metabolic Alterations In Estrogen Receptor-Positive Breast Cancer, Steven Tau

Dartmouth College Ph.D Dissertations

Estrogen receptor-positive breast cancer remains one of the most frequently diagnosed cancers in women. Despite adjuvant endocrine therapy reducing the rate of recurrence, there remains a significant proportion of patients whose breast cancer will recur years to decades after the initial diagnosis. The underlying biology of tumor cells in the period between initiation of adjuvant therapy and recurrence is relatively unexplored, preventing the development of better treatment options. From a genome-wide screening approach, we identified and characterized broad metabolic reprogramming associated with the persistent cell state. We demonstrate that a decreased ability to metabolize glucose in turn pushes a higher …

Near-Infrared Paired-Agent Imaging For In Vivo Quantification Of Receptor Occupancy In Tumor, Yichen Feng

Dartmouth College Ph.D Dissertations

Accurate assessment of drug receptor occupancy (RO) holds significant importance in both drug development and personalized medicine, as it facilitates quantitative characterization of dose-response relationship for a given drug. This information not only aids appropriate dose selection for clinical trials but also guides personalized dose optimization in precision medicine.

Molecular imaging, utilizing receptor-specific imaging agents for tissue visualization, has emerged as the major option for in vivo measurement of tissue RO. Nonetheless, the abnormal yet complex structure and hemodynamics of tumors often lead to substantial non-specific uptake and retention of imaging agents, thus introducing significant bias to RO measurements. To …

Exploring 3d Genome Interaction And Epigenetic Regulation Via Swi/Snf Complex And Deep Learning Models, Ruoyun Wang

Dartmouth College Ph.D Dissertations

The three-dimensional organization of the genome is fundamental in regulating gene expression and maintaining cellular function. This organization's complexities, influenced by epigenetic marks and chromatin remodeling complexes, are crucial for understanding genomic regulation. Among these, the SWI/SNF complexes are key, facilitating chromatin accessibility and regulating gene activity across cell types. The first part of my dissertation focuses on SWI/SNF complexes, exploring their role in chromatin remodeling and their impact on 3D genome architecture. Utilizing next-generation sequencing (NGS) techniques, this section investigates the interplay between these complexes and chromatin structure. During my research on the SWI/SNF complex, I was intrigued by …

Estrogen Receptor (Er) Alpha Regulatory Mechanisms And Therapeutic Strategies In Er+ Breast Cancer, Bianca A. Romo

Dartmouth College Ph.D Dissertations

Breast cancer is among the most frequently diagnosed cancers in the U.S. and is one of the leading causes of cancer-related mortalities, second to lung cancer. Estrogen receptor alpha-positive (ER+) breast cancer accounts for 2/3 of diagnosed cases. Patients diagnosed with this subtype of breast cancer typically undergo endocrine therapy that aims to mitigate the growth-promoting effects of estrogen/ER. While therapies are effective, 1/3 of patients will experience recurrence. To begin addressing this drug-resistant patient population, we investigated potential drug targets involved in response to treatment.

Coregulators have been implicated in the regulation of ER transcriptional activity and subsequently affecting …

Chromatin Regulation By Swi/Snf Remodelers In Somatic Stem Cell Maintenance And Transformation, Luke Thomas Deary

Dartmouth College Ph.D Dissertations

Cell identity is defined by the epigenome, whereby chromatin regulators work in concert to promote gene expression programs that serve a cell’s specialized purpose. Mutations in chromatin regulators are amongst the most frequent drivers of human disease, underscoring the importance of understanding their activities in maintaining cell identity and tissue function. In particular, mutations in subunits of the evolutionarily conserved SWI/SNF chromatin remodeling complexes drive diseases across human tissues in both development and adult tissue maintenance5. Three major SWI/SNF complexes exist: BAF, PBAF, and GBAF, which differ in their composition and genomic targeting but share an ATP-dependent catalytic activity to …

Regulation Of The Wnt/Wingless Receptor Lrp6/Arrow By The Deubiquitylating Complex Usp46, Zachary T. Spencer

Dartmouth College Ph.D Dissertations

The evolutionarily conserved Wnt/Wingless signal transduction pathway is critical for the proper development of all animals and implicated in numerous diseases in adulthood. Upon binding of the Wnt/Wingless ligand, a cascade of events culminates in inactivation of the destruction complex, a negative regulator of the pathway, and the subsequent formation of singalosomes which mediate pathway activation. A critical component of signalosome formation is the Wnt/Wingless receptor LRP6/Arrow. Upon canonical pathway activation, LRP6/Arrow undergoes activation via phosphorylation by several kinases and complexes with another Wnt/Wingless receptor Frizzled, along with several cytoplasmic components. While many studies have investigated the regulatory mechanisms of …

Understanding The Implications Of Lineage Plasticity In Breast Cancer Evolution And Chemotherapy Response, Gadisti Aisha Mohamed

Dartmouth College Ph.D Dissertations

Intra-tumoral heterogeneity and the presence of a phenotypically diverse cell population within a single tumor represents a major hurdle in the understanding of tumor progression and dynamics, and complicates the effective diagnosis and management of this disease. One of the ways by which tumors gain intra-tumoral variation is through the acquisition of phenotypic or lineage plasticity, whereby tumor cells evolve away from the lineage of origin and gain altered profiles. These alterations may impart specific survival benefits to different subpopulations of cells, enabling them to proliferate faster, migrate away from the site of the primary tumor or evade drug-induced elimination, …

Cell-Typing And Interaction Analysis Of The Immune Compartment Of The Tumor Microenvironment Using High-Resolution Omics Modalities, Courtney Taylor Schiebout

Dartmouth College Ph.D Dissertations

Single-cell RNA-sequencing (scRNA-seq) has provided a new frontier for the investigation of complex tissues. One ideal candidate for the utilization of this method is the tumor microenvironment (TME). The TME is often host to a complex set of cell populations and behaviors that can be highly influential for cancer inhibition or progression. This is especially true of the immune compartment of the TME: the presence of certain types of immune cells in the TME and their expression profiles can significantly affect cancer prognosis in some cases. By providing individual cell-level gene expression data, scRNA-seq can be highly informative for characterizing …

Characterization Of Cell Type-Specific Molecular Heterogeneity In Cancer Using Multi-Omic Approaches, Min Kyung Lee

Dartmouth College Ph.D Dissertations

Tumors are composed of heterogeneous cell types each with its own unique molecular profiles. Recent advances in single cell genomics technologies have begun to increase our understanding of the molecular heterogeneity that exists in tumors with particular focus on gene expression and chromatin accessibility profiles. However, due to limitations in methods for certain sample types and high cost for single cell genomics, bulk tumor molecular profiling has been and remains widely used. In addition, other facets of single cell epigenomic profiling, particularly methylation and hydroxymethylation, remains underexplored. Thus, investigations to understand the cell type specific epigenetic heterogeneity and the cooperation …

The Roles Of Epithelial–Mesenchymal Plasticity In Tumor Heterogeneity, Metastasis, And Patient Survival In Breast Cancer, Meredith Septer Brown

Dartmouth College Ph.D Dissertations

The Epithelial-to-Mesenchymal transition, a critical cellular process in development, is frequently co-opted by solid tumors to promote invasion and metastasis. In particular, the hybrid or intermediate EMT state, possessing both epithelial and mesenchymal characteristics, is associated with increased cancer stemness and plasticity. Similarly, intra-tumoral heterogeneity in solid tumors, in particular breast cancer, is associated with poor prognosis, tumor growth, proliferation, drug resistance, and metastasis. We sought to understand the link between the generation of intra-tumoral heterogeneity and the intermediate EMT state and their impact on tumor progression and patient prognosis. As part of my thesis work, I developed a model …

A Machine Learning Classifier Trained On Cancer Transcriptomes Detects Nf1 Inactivation Signal In Glioblastoma, Gregory P. Way, Robert J. Allaway, Stephanie J. J. Bouley, Camilo E. Fadul, Yolanda Sanchez, Casey Greene

Dartmouth Scholarship

We have identified molecules that exhibit synthetic lethality in cells with loss of the neurofibromin 1 (NF1) tumor suppressor gene. However, recognizing tumors that have inactivation of the NF1 tumor suppressor function is challenging because the loss may occur via mechanisms that do not involve mutation of the genomic locus. Degradation of the NF1 protein, independent of NF1 mutation status, phenocopies inactivating mutations to drive tumors in human glioma cell lines. NF1 inactivation may alter the transcriptional landscape of a tumor and allow a machine learning classifier to detect which tumors will benefit from synthetic lethal molecules. We …

Comparative Genetic Screens In Human Cells Reveal New Regulatory Mechanisms In Wnt Signaling, Andres M. Lebensohn, Ramin Dubey, Leif Neitzel, Ofelia Tacchelly-Benites

Dartmouth Scholarship

The comprehensive understanding of cellular signaling pathways remains a challenge due to multiple layers of regulation that may become evident only when the pathway is probed at different levels or critical nodes are eliminated. To discover regulatory mechanisms in canonical WNT signaling, we conducted a systematic forward genetic analysis through reporter-based screens in haploid human cells. Comparison of screens for negative, attenuating and positive regulators of WNT signaling, mediators of R-spondin-dependent signaling and suppressors of constitutive signaling induced by loss of the tumor suppressor adenomatous polyposis coli or casein kinase 1α uncovered new regulatory features at most levels of the …

The Adp-Ribose Polymerase Tankyrase Regulates Adult Intestinal Stem Cell Proliferation During Homeostasis In Drosophila, Zhenghan Wang, Ai Tian, Hassina Benchabane, Ofelia Tacchelly-Benites, Eungi Yang, Hisashi Nojima, Yashi Ahmed

Dartmouth Scholarship

Wnt/β-catenin signaling controls intestinal stem cell (ISC) proliferation, and is aberrantly activated in colorectal cancer. Inhibitors of the ADP-ribose polymerase Tankyrase (Tnks) have become lead therapeutic candidates for Wnt-driven cancers, following the recent discovery that Tnks targets Axin, a negative regulator of Wnt signaling, for proteolysis. Initial reports indicated that Tnks is important for Wnt pathway activation in cultured human cell lines. However, the requirement for Tnks in physiological settings has been less clear, as subsequent studies in mice, fish and flies suggested that Tnks was either entirely dispensable for Wnt-dependent processes in vivo, or alternatively, had tissue-specific roles. Here, …

Targeting Neddylation Induces Dna Damage And Checkpoint Activation And Sensitizes Chronic Lymphocytic Leukemia B Cells To Alkylating Agents, C Paiva, J C. Godbersen, A Berger, J R. Brown, A V. Danilov

Dartmouth Scholarship

Microenvironment-mediated upregulation of the B-cell receptor (BCR) and nuclear factor-κB (NF-κB) signaling in CLL cells resident in the lymph node and bone marrow promotes apoptosis evasion and clonal expansion. We recently reported that MLN4924 (pevonedistat), an investigational agent that inhibits the NEDD8-activating enzyme (NAE), abrogates stromal-mediated NF-κB pathway activity and CLL cell survival. However, the NAE pathway also assists degradation of multiple other substrates. MLN4924 has been shown to induce DNA damage and cell cycle arrest, but the importance of this mechanism in primary neoplastic B cells has not been studied. Here we mimicked the lymph node microenvironment using CD40 …

Synthetic Triterpenoids Can Protect Against Toxicity Without Reducing The Efficacy Of Treatment With Carboplatin And Paclitaxel In Experimental Lung Cancer, Karen T. Liby

Dartmouth Scholarship

Synthetic oleanane triterpenoids are multifunctional drugs being developed for the prevention and treatment of a variety of chronic diseases driven by inflammation and oxidative stress. Low nanomolar concentrations of triterpenoids inhibit the induction of inflammatory cytokines, and these drugs are potent activators of the Nrf2 cytoprotective pathway. In contrast, low micromolar concentrations of triterpenoids increased the production of ROS and induced apoptosis in a dose-dependent manner in malignant MCF10 CA1a breast cancer cells. Because cancer cells respond differently to ROS than normal cells, it should be possible to exploit these differences therapeutically. In an experimental model of lung cancer, the …

Sensitization Of Human Cancer Cells To Gemcitabine By The Chk1 Inhibitor Mk-8776: Cell Cycle Perturbation And Impact Of Administration Schedule In Vitro And In Vivo, Ryan Montano, Ruth Thompson, Injae Chung, Huagang Hou, Nadeem Khan, Alan Eastman

Dartmouth Scholarship

Chk1 inhibitors have emerged as promising anticancer therapeutic agents particularly when combined with antimetabolites such as gemcitabine, cytarabine or hydroxyurea. Here, we address the importance of appropriate drug scheduling when gemcitabine is combined with the Chk1 inhibitor MK-8776, and the mechanisms involved in the schedule dependence.

Killerflip: A Novel Lytic Peptide Specifically Inducing Cancer Cell Death, B Pennarun, G. Gaidos, O Bucur, A Tinari

Dartmouth Scholarship

One of the objectives in the development of effective cancer therapy is induction of tumor-selective cell death. Toward this end, we have identified a small peptide that, when introduced into cells via a TAT cell-delivery system, shows a remarkably potent cytoxicity in a variety of cancer cell lines and inhibits tumor growth in vivo, whereas sparing normal cells and tissues. This fusion peptide was named killer FLIP as its sequence was derived from the C-terminal domain of c-FLIP, an anti-apoptotic protein. Using structure activity analysis, we determined the minimal bioactive core of killerFLIP, namely killerFLIP-E. Structural analysis of cells using …

Interleukin-1Β Mediates Metalloproteinase-Dependent Renal Cell Carcinoma Tumor Cell Invasion Through The Activation Of Ccaat Enhancer Binding Protein Β, Brenda L. Petrella, Matthew P. P. Vincenti

Dartmouth Scholarship

Effective treatment of metastatic renal cell carcinoma (RCC) remains a major medical concern, as these tumors are refractory to standard therapies and prognosis is poor. Although molecularly targeted therapies have shown some promise in the treatment of this disease, advanced RCC tumors often develop resistance to these drugs. Dissecting the molecular mechanisms underlying the progression to advanced disease is necessary to design alternative and improved treatment strategies. Tumor-associated macrophages (TAMs) found in aggressive RCC tumors produce a variety of inflammatory cytokines, including interleukin-1 b (IL-1b). Moreover, the presence of TAMs and high serum levels of IL-1b in RCC patients correlate …

Pv1 Down-Regulation Via Shrna Inhibits The Growth Of Pancreatic Adenocarcinoma Xenografts, Sophie J. Deharvengt, Dan Tse, Olga Sideleva, Caitlin Mcgarry, Jason R. Gunn, Daniel S. Longnecker, Catherine Carriere, Radu V. Stan

Dartmouth Scholarship

PV1 is an endothelial-specific protein with structural roles in the formation of diaphragms in endothelial cells of normal vessels. PV1 is also highly expressed on endothelial cells of many solid tumours. On the basis of in vitro data, PV1 is thought to actively participate in angiogenesis. To test whether or not PV1 has a function in tumour angiogenesis and in tumour growth in vivo, we have treated pancreatic tumour-bearing mice by single-dose intratumoural delivery of lentiviruses encoding for two different shRNAs targeting murine PV1. We find that PV1 down-regulation by shRNAs inhibits the growth of established tumours derived from two …

Cdk1 And Plk1 Mediate A Clasp2 Phospho-Switch That Stabilizes Kinetochore–Microtubule Attachments, Ana R. R. Maia, Zaira Garcia, Lilian Kabeche, Marin Barisic

Dartmouth Scholarship

Accurate chromosome segregation during mitosis relies on a dynamic kinetochore (KT)-microtubule (MT) interface that switches from a labile to a stable condition in response to correct MT attachments. This transition is essential to satisfy the spindle-assembly checkpoint (SAC) and couple MT-generated force with chromosome movements, but the underlying regulatory mechanism remains unclear. In this study, we show that during mitosis the MT- and KT-associated protein CLASP2 is progressively and distinctively phosphorylated by Cdk1 and Plk1 kinases, concomitant with the establishment of KT-MT attachments. CLASP2 S1234 was phosphorylated by Cdk1, which primed CLASP2 for association with Plk1. Plk1 recruitment to KTs …

Variations In Mre11/Rad50/Nbs1 Status And Dna Damage-Induced S-Phase Arrest In The Cell Lines Of The Nci60 Panel, Kristen M. K. Garner, Alan Eastman

Dartmouth Scholarship

The Mre11/Rad50/Nbs1 (MRN) complex is a regulator of cell cycle checkpoints and DNA repair. Defects in MRN can lead to defective S-phase arrest when cells are damaged. Such defects may elicit sensitivity to selected drugs providing a chemical synthetic lethal interaction that could be used to target therapy to tumors with these defects. The goal of this study was to identify these defects in the NCI60 panel of cell lines and identify compounds that might elicit selective cytotoxicity.

Cd277 Is A Negative Co-Stimulatory Molecule Universally Expressed By Ovarian Cancer Microenvironmental Cells, Juan R. Cubillos-Ruiz, Diana Martinez, Uciane K. Scarlett, Melanie R. Rutkowski, Yolanda C. Nesbeth, Ana L. Camposeco-Jacobs, Jose R. Conejo-Garcia

Dartmouth Scholarship

CD277, a member of the butyrophilin subfamily 3 (BTN3), shares significant sequence similarities and predicted common structural features with inhibitory B7-H4 and other members of the B7 superfamily. Here we report that CD277 is consistently expressed in stromal, as well as tumor cells in the microenvironment of human advanced ovarian carcinoma specimens, both of primary and metastatic origin. MHC-II+ myeloid antigenpresenting leukocytes (dendritic cells and macrophages) express significantly higher levels of surface CD277, compared to other tumor-infiltrating leukocyte subsets, and this expression is significantly up-regulated by multiple common tumor microenvironmental signals, including VEGF and CCL3. Most importantly, engagement of CD277 …

Wnt Pathway Reprogramming During Human Embryonal Carcinoma Differentiation And Potential For Therapeutic Targeting, Grace E. Snow, Allison C. Kasper, Alexander M. Busch, Elisabeth Schwarz, Katherine E. Ewings, Thomas Bee, Michael J. Spinella, Ethan Dmitrovsky, Sarah J. Freemantle

Dartmouth Scholarship

Testicular germ cell tumors (TGCTs) are classified as seminonas or non-seminomas of which a major subset is embryonal carcinoma (EC) that can differentiate into diverse tissues. The pluripotent nature of human ECs resembles that of embryonic stem (ES) cells. Many Wnt signalling species are regulated during differentiation of TGCT-derived EC cells. This study comprehensively investigated expression profiles of Wnt signalling components regulated during induced differentiation of EC cells and explored the role of key components in maintaining pluripotency.

Growth Factor–Induced Shedding Of Syndecan-1 Confers Glypican-1 Dependence On Mitogenic Responses Of Cancer Cells, Kan Ding, Martha Lopez-Burks, José A. Sánchez-Duran, Murray Korc, Arthur D. Lander

Dartmouth Scholarship

The cell surface heparan sulfate proteoglycan (HSPG) glypican-1 is up-regulated by pancreatic and breast cancer cells, and its removal renders such cells insensitive to many growth factors. We sought to explain why the cell surface HSPG syndecan-1, which is also up-regulated by these cells and is a known growth factor coreceptor, does not compensate for glypican-1 loss. We show that the initial responses of these cells to the growth factor FGF2 are not glypican dependent, but they become so over time as FGF2 induces shedding of syndecan-1. Manipulations that retain syndecan-1 on the cell surface make long-term FGF2 responses glypican …

Ube1l Is A Retinoid Target That Triggers Pml/Rarα Degradation And Apoptosis In Acute Promyelocytic Leukemia, Sutisak Kitareewan, Ian Pitha-Rowe, David Sekula, Christopher H. Lowrey, Michael J. Nemeth, Todd R. Golub, Sarah J. Freemantle, Ethan Dmitrovsky

Dartmouth Scholarship

All-trans-retinoic acid (RA) treatment induces remissions in acute promyelocytic leukemia (APL) cases expressing the t(15;17) product, promyelocytic leukemia (PML)/RA receptor α (RARα). Microarray analyses previously revealed induction of UBE1L (ubiquitin-activating enzyme E1-like) after RA treatment of NB4 APL cells. We report here that this occurs within 3 h in RA-sensitive but not RA-resistant APL cells, implicating UBE1L as a direct retinoid target. A 1.3-kb fragment of the UBE1L promoter was capable of mediating transcriptional response to RA in a retinoid receptor-selective manner. PML/RARα, a repressor of RA target genes, abolished this UBE1L promoter activity. A hallmark of …