Biological Phenomena, Cell Phenomena, and Immunity Commons^™

Membrane Bound Il21 Promotes Natural Killer Cell Expansion Through Mir 124-3p Mediated Regulation, Anitha Somanchi

Dissertations and Theses (Open Access)

Natural Killer (NK) cells are cells of the innate immune system that act as first line of defense against viral infections and participate in tumor immune surveillance. NK cells do not cause graft versus host disease (GvHD), or require prior antigen exposure to exert anti-tumor activity, hence are an attractive choice for immunotherapy applications. Owing to small numbers of NK cells in peripheral blood (1-32%, with a 6% median), ex vivo expansion of NK cells is critical for NK cell adoptive immunotherapy, various expansion platforms have been explored over the decades. We developed a robust platform for ex vivo expansion …

Effect Of Extracellular Survivin And Lymphoma Exosomes On Natural Killer Cells, Heather R. Ferguson Bennit

Loma Linda University Electronic Theses, Dissertations & Projects

Tumors alter their microenvironment to promote survival using methods such as angiogenesis promotion, growth signals, and immune suppression. The immune system becomes unresponsive to transformed neoplastic cells through a variety of methods including T cell suppression, increased myeloid-derived suppressor cells (MDSCs), and reduced natural killer (NK) cell activity. NK cells have inherent killing capabilities and thus are among the first responders in recognizing and destroying abnormal cells. However, many types of cancers inhibit the surveillance and cytotoxic abilities of NK cells by releasing exosomes, vesicles that can modulate the tumor microenvironment (TME) and intercellular communication for the purpose of enhancing …

Transactivation Of The Estrogen Receptor Promoter By Brca1, William B. Archey, Bradley A. Arrick

Dartmouth Scholarship

Background: Absence of the estrogen receptor-α (ER) is perhaps the most distinctive pathological feature of breast cancers arising in women who inherit a mutation in BRCA1. Two hypotheses, not necessarily mutually exclusive, exist in the literature that describe mechanisms of ER transcriptional repression in breast cancer. One hypothesis suggests that methylation of cytosine–guanine dinucleotides (CpGs) primarily mediates repression, while the other maintains that transcriptional control is mediated by certain positive and negative promoter elements.

Methods: To determine if wild type BRCA1 could induce activity of the ER promoter, we performed a series of tran- sient transfections with ER promoter segments …

Employing The Enzyme Cofactor Function Of Ascorbic Acid To Affect Oncogenic Pathways In Human Melanoma: Modulating Hypoxia Inducible Factor-1Α And Dna Demethylation To Reduce Malignant Potential, Adam Patrick Fischer

Theses, Dissertations and Capstones

Dioxygenase enzymes such as the HIF hydroxylases (PHD1-3, FIH) and the Ten-eleven translocation (TET1-3) enzymes regulate the activity of the hypoxia inducible factor-1_a (HIF1_a) transcription factor and the DNA methylation status of cells, respectively. Aberrant accumulation and activation of HIF-1_a can allow malignant cells to acquire attributes that promote progression, chemotherapy resistance, and survival, while aberrant hypermethylation of gene promoters can silence the expression of tumor suppressor genes essential to preventing tumorigenesis. Inadequate levels of intracellular ascorbic acid (AA), a necessary cofactor for optimal dioxygenase enzyme function, could potentiate these tumorigenic conditions. In fact, plasma levels …

Mitochondrial Akt Regulation Of Hypoxic Tumor Reprogramming., Young Chan Chae, Valentina Vaira, M. Cecilia Caino, Hsin-Yao Tang, Jae Ho Seo, Andrew V. Kossenkov, Luisa Ottobrini, Cristina Martelli, Giovanni Lucignani, Irene Bertolini, Marco Locatelli, Kelly G. Bryant, Jagadish C. Ghosh, Sofia Lisanti, Bonsu Ku, Silvano Bosari, Lucia R. Languino, David W. Speicher, Dario C. Altieri

Department of Cancer Biology Faculty Papers

Hypoxia is a universal driver of aggressive tumor behavior, but the underlying mechanisms are not completely understood. Using a phosphoproteomics screen, we now show that active Akt accumulates in the mitochondria during hypoxia and phosphorylates pyruvate dehydrogenase kinase 1 (PDK1) on Thr346 to inactivate the pyruvate dehydrogenase complex. In turn, this pathway switches tumor metabolism toward glycolysis, antagonizes apoptosis and autophagy, dampens oxidative stress, and maintains tumor cell proliferation in the face of severe hypoxia. Mitochondrial Akt-PDK1 signaling correlates with unfavorable prognostic markers and shorter survival in glioma patients and may provide an "actionable" therapeutic target in cancer.

Theaflavin-3, 3'-Digallate Induces Apoptosis And G2 Cell Cycle Arrest Through The Akt/Mdm2/P53 Pathway In Cisplatin-Resistant Ovarian Cancer A2780/Cp70 Cells, Youying Tu, Eunhye Kim, Ying Gao, Gary O. Rankin, Bo Li, Yi Charlie Chen

Pharmacology, Physiology and Toxicology

Ovarian cancer is the most lethal gynecological cancer among women worldwide. Adverse side effects and acquired resistance to conventional platinum based chemotherapy are major impediments in ovarian cancer treatment, and drive the development of more selective anticancer drugs that target cancer-specific defects. In this study, theaflavin-3, 3'-digallate (TF3), the major theaflavin monomer in black tea, exhibited a potent growth inhibitory effect on the cisplatinresistant ovarian cancer A2780/CP70 cells (IC50, 23.81 μM), and was less cytotoxic to a normal ovarian IOSE‑364 cells (IC50, 59.58 μM) than to the cancer cells. Flow cytometry analysis indicated that TF3 induced preferential apoptosis and G2 …

Does The Expression Of Ki-67, P16 And Cox-2 At Initial Diagnosis Of Breast Atypia Or Usual Ductal Hyperplasia Predict A Second Clinically Significant Event?, Judy A. Tjoe, Philippe Gascard, Jianxin Zhao, Gary F. Neitzel, Maharaj Singh, Brittany Last, James Marx, Thea Tlsty, Sanjay Kansra

Journal of Patient-Centered Research and Reviews

Background: Women diagnosed with atypical ductal hyperplasia (ADH) or atypical lobular hyperplasia (ALH) have a fivefold increased risk of developing breast cancer. Because ADH/ALH can be precursors or predictive markers of a subsequent clinically significant event (SCSE), i.e. atypia, in situ or invasive carcinoma, the clinical outcome for these patients ranges anywhere from remission to invasive malignancy. Currently we cannot predict which atypical breast lesion is likely to be associated with future cancer, resulting in aggressive management and, possibly, overtreatment. Kerlikowske et al. reported that a combination of three biomarkers (cell cycle regulator p16INK4a, proliferation antigen Ki-67 and stress response …

Correlation Matrix Analysis Identifies Gene Signatures Of Immune Cell Subsets And Their Interactions In Follicular Lymphoma, Jason R. Westin

Dissertations and Theses (Open Access)

There are important but ill-defined interactions between benign immune cell subsets and neoplastic B cells within follicular lymphoma (FL). Using the novel technique of correlation matrix analysis (CMA) of publicly available FL whole-tumor gene expression profiling (GEP) data, we have identified signatures of immune cell subsets. Overall survival correlated most highly with a model using signatures of macrophages, T cells, and stroma, which was able to add significantly to existing clinical prognostic tools. From our own data of a cohort of 43 FL tumors sorted into B-cell and non-B cell (NB) fractions for GEP, CMA of the tumor infiltrating NB …

Modeling The Adaptive Immune Response To Mutation-Generated Antigens, Rory J. Geyer

University Scholar Projects

Somatic mutations may drive tumorigenesis or lead to new, immunogenic epitopes (neoantigens). The immune system is thought to represses neoplastic growths through the recognition of neoantigens presented only by tumor cells. To study mutations as well as the immune response to mutation-generated antigens, we have created a conditional knockin mouse line with a gene encoding, 5’ to 3’, yellow fluorescent protein (YFP), ovalbumin (which is processed to the immunologically recognizable peptide, SIINFEKL), and cyan fluorescent protein (CFP), or, YFP-ovalbumin-CFP. A frame shift mutation has been created at the 5’ end of the ovalbumin gene, hence YFP should always be expressed, …

Modeling The Adaptive Immune Response To Mutation-Generated Antigens, Rory J. Geyer

Honors Scholar Theses

Somatic mutations may drive tumorigenesis or lead to new, immunogenic epitopes (neoantigens). The immune system is thought to represses neoplastic growths through the recognition of neoantigens presented only by tumor cells. To study mutations as well as the immune response to mutation-generated antigens, we have created a conditional knockin mouse line with a gene encoding, 5’ to 3’, yellow fluorescent protein (YFP), ovalbumin (which is processed to the immunologically recognizable peptide, SIINFEKL), and cyan fluorescent protein (CFP), or, YFP-ovalbumin-CFP. A frame shift mutation has been created at the 5’ end of the ovalbumin gene, hence YFP should always be expressed, …

Benzyl Isothiocyanate As An Adjuvant Chemotherapy Option For Head And Neck Squamous Cell Carcinoma, Mary Allison Wolf

Theses, Dissertations and Capstones

Isothiocyanates (ITCs) are natural phytochemicals produced by cruciferous vegetables. Recent evidence supports that, in addition to cancer prevention, ITCs can use various mechanisms to target malignant cells. Current therapies for cancer often provoke detrimental side effects, however clinical evidence supports that ITCs have little to no side effects in patients. Consequently, ITCs may be a promising treatment option for cancer patients, especially patients suffering from head and neck squamous cell carcinoma (HNSCC).

Despite recent improvements in cancer treatment, overall survival of advanced HNSCC has not improved in the past three decades. Metastasis and chemoresistance represent two detrimental events that greatly …

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

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 …

The Role Of Ptip In Breast Cancer, Lina Niu

Theses, Dissertations and Capstones

In the U.S., breast cancer comprises about 30% of all cancer cases (excluding skin cancer) in women. Such a high incidence makes breast cancer a significant health concern, but our understanding of the molecular and cellular mechanisms of this disease is still limited. Growing evidence suggests that the development of human breast cancer may involve epigenetics, which attributes changes in phenotype to mechanisms other than changes in the DNA sequence itself. Histones as the chief proteins of chromatin work on gene expression, and methylation of histone 3 lysine 4 (H3K4) results in transcriptional activation. Lately, Paired box (Pax) trans-activation domain-interacting …

Role Of Prostaglandin E2 In The Regulation Of Pancreatic Stellate Cells Hyper Activity Associated With Pancreatic Cancer, Chantale Charo

Dissertations and Theses (Open Access)

Pancreatic cancer is one of the most lethal type of cancer due to its high metastasis rate and resistance to chemotherapy. Pancreatic fibrosis is a constant pathological feature of chronic pancreatitis and the hyperactive stroma associated with pancreatic cancer. Strong evidence supports an important role of cyclooxygenase-2 (COX-2) and COX-2 generated prostaglandin E2 (PGE2) during pancreatic fibrosis. Pancreatic stellate cells (PSC) are the predominant source of extracellular matrix production (ECM), thus being the key players in both diseases. Given this background, the primary objective is to delineate the role of PGE2 on human pancreatic stellate cells (PSC) hyper activation associated …

Pitx2 Is Overexpressed In Follicular Cell-Derived Thyroid Cancer And Promotes Thyroid Cancer Proliferation By Regulating Cell Cycle, Yue Huang

Theses, Dissertations and Capstones

Thyroid cancer is the most prevailing malignancy of the endocrine system. Its incidence is rapidly rising at the second fastest rate of all malignancies in the United States, making it a significant health problem. Although the majority of thyroid cancer is slowly-growing and well-differentiated, available treatment options are very limited, and most of them require complete removal of the thyroid gland and surrounding tissues. Patients who have undergone thyroid removal have to take life-long hormone replacement therapy, which is very inconvenient and costly. Therefore, there is an urgent need to develop new treatments for this disease. As a prerequisite for …

Pp32 (Anp32a) Expression Inhibits Pancreatic Cancer Cell Growth And Induces Gemcitabine Resistance By Disrupting Hur Binding To Mrnas., Timothy K Williams, Christina L Costantino, Nikolai A Bildzukewicz, Nathan G Richards, David W Rittenhouse, Lisa Einstein, Joseph A Cozzitorto, Judith C Keen, Abhijit Dasgupta, Myriam Gorospe, Gregory E Gonye, Charles J Yeo, Agnieszka K Witkiewicz, Jonathan R Brody

Department of Surgery Faculty Papers

The expression of protein phosphatase 32 (PP32, ANP32A) is low in poorly differentiated pancreatic cancers and is linked to the levels of HuR (ELAV1), a predictive marker for gemcitabine response. In pancreatic cancer cells, exogenous overexpression of pp32 inhibited cell growth, supporting its long-recognized role as a tumor suppressor in pancreatic cancer. In chemotherapeutic sensitivity screening assays, cells overexpressing pp32 were selectively resistant to the nucleoside analogs gemcitabine and cytarabine (ARA-C), but were sensitized to 5-fluorouracil; conversely, silencing pp32 in pancreatic cancer cells enhanced gemcitabine sensitivity. The cytoplasmic levels of pp32 increased after cancer cells are treated with certain stressors, …

Capsaicin Displays Anti-Proliferative Activity Against Human Small Cell Lung Cancer In Cell Culture And Nude Mice Models Via The E2f Pathway, Kathleen C. Brown, Theodore R. Witte, W. Elaine Hardman, Haitao Luo, Yi C. Chen, A. Betts Carpenter, Jamie K. Lau, Piyali Dasgupta

Biochemistry and Microbiology

Background: Small cell lung cancer (SCLC) is characterized by rapid progression and low survival rates. Therefore, novel therapeutic agents are urgently needed for this disease. Capsaicin, the active ingredient of chilli peppers, displays antiproliferative activity in prostate and epidermoid cancer in vitro. However, the anti-proliferative activity of capsaicin has not been studied in human SCLCs. The present manuscript fills this void of knowledge and explores the anti-proliferative effect of capsaicin in SCLC in vitro and in vivo.

Methodology/Principal Findings: BrdU assays and PCNA ELISAs showed that capsaicin displays robust anti-proliferative activity in four human SCLC cell lines. Furthermore, capsaicin potently …

Rbc And Wbc Fatty Acid Composition Following Consumption Of An Omega 3 Supplement: Lessons For Future Clinical Trials, Theodore R. Witte, Alexander J. Salazar, Oscar F. Ballester, W. Elaine Hardman

Biochemistry and Microbiology

Background: Results from increasing numbers of in vitro and in vivo studies have demonstrated that omega 3 fatty acids incorporated in cell culture media or in the diet of the animals can suppress the growth of cancers. When human clinical trials are initiated to determine the ability of omega 3 fatty acids to alter growth or response to chemotherapeutic interventions of cancers, it will be essential to determine the omega 3 intake of individuals in the trial to determine compliance with consumption of the supplement and to correlate with endpoints of efficacy. We wondered if the fatty acid composition of …

Genetic And Environmental Factors Suggest That Dietary Fatty Acid Content, Lipid Metabolism, And Bone Properties Are Key Regulators Of Myeloid Progenitor Cell Frequency, Melinda E. Varney

Theses, Dissertations and Capstones

Acute myelogenous leukemia (AML) and its precursors are the result of the dysregulation of hematopoiesis. Hematopoiesis proceeds in a stepwise manner, beginning with hematopoietic stem cells, continuing to develop into various stages of progenitor cells, and finally becoming fully functional blood cells. As this process goes awry, immature, functionless cells of the myeloid lineage proliferate out of control. Discerning how myeloid progenitor frequency is regulated allows for a better understanding of how the process may lose control. Hematopoiesis has been shown to depend on genetic and environmental factors. In this work, I have added to this knowledge base by providing …

The Expression And Function Of Hypoxia Inducible Factor-1Α In Human Melanoma, Sandeep S. Joshi

Theses, Dissertations and Capstones

Hypoxia inducible factor-1α (HIF-1α) protein, a key regulator of oxygen homeostasis, is stabilized under hypoxia and degraded under normal oxygen tension. Here, the human melanoma cells were found to express an elevated amount of HIF-1α mRNA and protein relative to normal human melanocytes under normoxic conditions. The amount of HIF-1α expressed is roughly correlated with the stage of melanoma from which the cell line was established. In addition, a splice variant mRNA of HIF-1α785 is expressed at higher levels than full-length HIF-1α mRNA in the more aggressive melanoma cells. This splice variant lacks part of the oxygen regulation domain. Ectopic …

Treatment Strategies In Acute Myelogenous Leukemia : Investigating Hsp90 And P53 As Targets, Jennifer M. Napper

Theses, Dissertations and Capstones

Acute myelogenous leukemia (AML) is the deadliest of the lymphatic and bone marrow cancers. Patients diagnosed with AML have a five year survival rate of 23.4%. AML is characterized by an accumulation of undifferentiated and functionless myeloid precursors in the bone marrow and blood. Heat shock protein 90 (Hsp90) inhibitors, such as 17-AAG, an analog of geldanamycin (GM), are currently undergoing phase I, and II and III clinical trials for various cancers with mixed results. I found distinct responses to 17-AAG treatment among the AML cell lines tested. I also discovered two mutant TP53 alleles in Kasumi-3 cells, an AML …

The P53-Induced Siva-1 Plays A Significant Role In Cisplatin-Mediated Apoptosis, John L. Barkinge, Radhika Gudi, Hawkins Sarah, Fei Chu, Alip Borthakur, Bellur S. Prabhakar

Clinical & Translational Sciences

Background: The pro-apoptotic protein Siva-1 functions in both extrinsic and intrinsic cell death signaling; however, the exact contribution of the endogenous Siva-1 to DNA damage-induced apoptosis is unclear. Using cisplatin, a chemotherapeutic drug, to induce DNA damage and cell death, we determined the role of Siva-1.

Methods: Cisplatin treated HCT116 colorectal carcinoma cells (p53+/+ and -/-) were used in the study. With the help of recombinant lentivirus that can express siSiva (siRNA that specifi cally targets Siva-1), we also generated Siva-1 knockdown HCT116 cells. Apoptosis was determined by tetramethyl rhodamine methyl ester (TMRM) staining and propidium iodide (PI) staining.

Results: …

The Function And Mechanism Of Chmp1a In Tumor Development, Jing Li

Theses, Dissertations and Capstones

Chmp1A (Chromatin modifying protein 1A/Charged multivesicular protein 1A) is a member of the ESCRT-III (Endosomal Sorting Complex Required for Transport) family, which mediates trafficking via MVB (multivesicular body) formation and sorting. Our studies suggest that Chmp1A is a novel tumor suppressor, especially in the pancreas. Knockdown of Chmp1A resulted in an increase of anchorage-independent growth of HEK 293T cells. Moreover, we showed that Chmp1A depleted HEK 293T cells forms tumor in xenograft mice. Knockdown of Chmp1A in PanC-1 cells promoted cell growth. In contrast, Doxycycline induced over-expression of Chmp1A in pancreatic cancer cells (PanC-1) resulted in cell growth inhibition, tumor …

An In Vitro Model Of Ovarian Cancer: Studying The Effects Of Talc And Pycnogenol®, Amber Renée Buz'zard

Loma Linda University Electronic Theses, Dissertations & Projects

Ovarian cancer is the sixth most common cancer and accounts for more deaths than any other cancer of the female reproductive system. The American Cancer Society has suggested that poor diet, talc and industrial pollutants may increase the risk of developing ovarian cancer. Talc is ubiquitous and concern is raised about its safety, role as a possible carcinogen and known ability to cause irritation and inflammation. Due to the silent nature of ovarian cancer, chemoprevention is a high priority. The most useful chemopreventive compounds will inhibit, delay or reverse carcinogenesis, and can be taken for long periods of time with …

Therapeutic Electromagnetic Field (Temf) And Gamma Irradiation On Human Breast Cancer Xenograft Growth, Angiogenesis And Metastasis, Ivan L. Cameron, Luzhe Sun, Nicholas Short, W. Elaine Hardman, C. Douglas Williams

Biochemistry and Microbiology

Background

The effects of a rectified semi-sinewave signal (15 mT amplitude, 120 pulses per second, EMF Therapeutics, Inc.) (TEMF) alone and in combination with gamma irradiation (IR) therapy in nude mice bearing a human MDA MB231 breast cancer xenograft were tested. Green fluorescence protein transfected cancer cells were injected into the mammary fat pad of young female mice. Six weeks later, mice were randomly divided into four treatment groups: untreated controls; 10 minute daily TEMF; 200 cGy of IR every other day (total 800 cGy); IR plus daily TEMF. Some mice in each group were euthanized 24 hours after the …

Endothelial Cell Pseudopods And Angiogenesis Of Breast Cancer Tumors, Ivan L. Cameron, Nicholas Short, Luzhe Sun, W. Elaine Hardman

Biochemistry and Microbiology

Background

A neoplastic tumor cannot grow beyond a millimeter or so in diameter without recruitment of endothelial cells and new blood vessels to supply nutrition and oxygen for tumor cell survival. This study was designed to investigate formation of new blood vessels within a human growing breast cancer tumor model (MDA MB231 in mammary fat pad of nude female mouse). Once the tumor grew to 35 mm³, it developed a well-vascularized capsule. Histological sections of tumors greater than 35 mm³were stained with PAS, with CD-31 antibody (an endothelial cell maker), or with hypoxia inducible factor 1α …

Dietary Omega-3 Fatty Acids And Ionizing Irradiation On Human Breast Cancer Xenograft Growth And Angiogenesis, W. Elaine Hardman, Luzhe Sun, Nicholas Short, Ivan L. Cameron

Biochemistry and Microbiology

Background

The effects of an omega-3 (n-3) fatty acid enriched diet alone and in combination with gamma irradiation (IR) therapy in nude mice bearing a human MDA-MB231 breast cancer xenograft were tested. The cancer cells were injected into the mammary fat pad of young female mice. Six weeks later, mice were randomly divided into two diet groups: 1) mice with 10% corn oil (rich in omega 6 fatty acids) in their food, 2) mice consuming a 10% fat diet that was enriched in n-3 fatty acids. After two weeks on the diet, treatment with 200 cGy of IR every second …

The Anti-Proliferation Effects Of Lycopene On Breast Cancer Cells, Tixieanna Dissmore

Loma Linda University Electronic Theses, Dissertations & Projects

Background: The incidence and deaths from breast cancer represent the most cause of all cancer deaths among women. Lycopene, the carotenoid in tomatoes has been associated with decreasing risk of prostate, breast, and digestive tract cancers. Various mechanisms of lycopene action have been proposed, including antioxidant activity and pro-differentiation activities. Identifying changes in the expression of proteins modified by lycopene can provide information to study the modulating effects of lycopene carcinogenesis and tumorigenesis development.

Objective: The objective was to study the anti-proliferative effects of lycopene on MCF- 7 human breast cancer cells and to identify changes in protein expression patterns. …

High Dietary Level Of Synthetic Vitamin E On Lipid Peroxidation, Membrane Fatty Acid Composition And Cytotoxicity In Breast Cancer Xenograft And In Mouse Host Tissue, Ivan L. Cameron, Jesus Munoz, Christopher J. Barnes, W. Elaine Hardman

Biochemistry and Microbiology

Background

d-α-tocopherol is a naturally occurring form of vitamin E not previously known to have antitumor activity. Synthetic vitamin E (sE) is a commonly used dietary supplement consisting of a mixture of d-α-tocopherol and 7 equimolar stereoisomers. To test for antilipid peroxidation and for antitumor activity of sE supplementation, two groups of nude mice bearing a MDA-MB 231 human breast cancer tumor were fed an AIN-76 diet, one with and one without an additional 2000 IU/kg dry food (equivalent to 900 mg of all-rac-α-tocopherol or sE). This provided an intake of about 200 mg/kg body weight per day. The mice …

The Role Of Ap-1 Transcription Complex In Retinoic Acid-Dependent B16 Melanoma Cell Growth Arrest And Differentiation, Ying Huang

Theses, Dissertations and Capstones

Our laboratory has been studying the effects of all-trans retinoic acid (atRA) on the growth and differentiation of the B16 mouse melanoma cells. RA inhibits both anchorage-dependent and –independent growth and stimulates melanin production in B16 cells, which are accompanied by an increase in AP-1 activity. To further investigate the RA-induced AP-1 activity, I established clones of B16 stably expressing an AP-1-luciferase reporter gene. Treatment of these clones with phorbol dibutyrate (PDB), a known activator of AP-1, rapidly increased AP-1 activity which reached its maximum level at 2-4 h and returned to baseline level by 24 h. In contrast, RA …