Biochemistry, Biophysics, and Structural Biology Commons^™

Variations On A Theme: Intricacies Of Unanchored Poly-Ubiquitin Signaling And Toxicity, Jessica Renee Blount-Pacheco

Wayne State University Dissertations

Ubiquitin is an 8.5 kDa post-translational modifier involved in essentially all eukaryotic cellular processes. Through a process called ubiquitination, ubiquitinating enzymes chemically attach ubiquitin to substrate proteins to control their fates, resulting in anything from their recruitment into signaling pathways to their proteasomal degradation, with a plethora of possibilities in between. Ubiquitin molecules can also be attached to one another, resulting in poly-ubiquitin chains with various effects depending on the number of ubiquitin molecules and the specific amino acid residues used to link them together. While most poly-ubiquitin in the cell exists as conjugated species, there are also untethered poly-ubiquitin …

The Role Of The Cell-Surface Protease Tmprss13 In Colorectal Cancer, Fausto Alexander Varela

Wayne State University Dissertations

Colorectal cancer (CRC) is one of the most common and deadly cancers in both men and women in the United States. Extracellular proteolysis is often dysregulated in cancer including (CRC), resulting in degradation of extracellular matrix, as well as cleavage, processing, or shedding of cell adhesion molecules, growth factors, and cytokines. Several members of the type II transmembrane serine protease (TTSP) family have been shown to play critical roles in cancer progression; however, many family members have not yet been characterized in malignancy. We identified TMPRSS13 transcript to be upregulated in CRC compared to normal colon. This increase was confirmed …

Characterization Of Cytosolic Sulfotransferase Expression And Regulation In Human Liver And Intestine, Sarah Talal Dubaisi

Wayne State University Dissertations

SULTs are conjugation enzymes that can modify the activity of a myriad of foreign and endogenous molecules. SULT expression was detected in various human tissues, including liver, small intestine, and colon. There are 13 human SULT genes that are classified into 4 families, SULT1, SULT2, SULT4, and SULT6. In humans, SULT1 and SULT2 families include 11 genes that are further divided into 6 subfamilies. In addition to their role in xenobiotic detoxification and regulation of physiological processes, SULT enzymes were implicated in the bioactivation of procarcinogens. Previous studies detected the expression of most SULT1 and SULT2 enzymes during early development, …

Biochemical, Structural, And Drug Design Studies Of Norovirus And Zika Virus Proteases, Ben Kuiper

Wayne State University Dissertations

Noroviruses, which are the leading cause of acute gastroenteritis, cause an estimated 677 million infections and 213,000 deaths each year worldwide. Noroviruses are classified into seven genogroups (GI-GVII); GI, GII, and GIV have been shown to be infectious in humans. However, GII noroviruses cause the majority of outbreaks (89%). No pharmacologic treatment or vaccine currently exists to treat or prevent norovirus infections.

Recently, the development of a norovirus replicon system, a murine model of norovirus infection, and the development of a biochemical protease assay have allowed for the design and development of norovirus inhibitors. However, the replicon and biochemical assay …

Structural Characterization And Therapeutic Utility Of The Proton-Coupled Folate Transporter, Michael Roy Wilson

Wayne State University Dissertations

Folate is a B9 vitamin essential to DNA synthesis. The proton-coupled folate transporter (PCFT) is a newly discovered proton/folate symporter with an acidic pH optimum and broad expression across a variety of solid tumor types, with limited expression in normal tissues. Several antifolate molecules have been developed as cancer therapeutics, although these classical antifolates display numerous off-target effects due to transport by the ubiquitous reduced folate carrier (RFC). In this dissertation, we determine the roles of multiple PCFT structure/function domains, and develop PCFT-specific antifolates to target solid tumors. We utilize substituted cysteine accessibility methods (SCAM) to identify a novel reentrant …

The Therapeutic Targeting Of Folate Receptor Alpha Positive Tumors Via Folate Receptor Selective Novel 5- And 6- Substituted Pyrrolo [2,3-D]Pyrimidine Antifolates", Shermaine Kimberly Mitchell-Ryan

Wayne State University Dissertations

Ovarian Cancer is the fifth leading cause of cancer-related death of women in the United States. Epithelial Ovarian Cancer (EOC) constitutes 85-90% of malignancies within the ovary, with an alarming majority of these cases diagnosed at advanced stage. While most patients are initially highly responsive to the current treatment standard, there is a very high probability that they will recur with a drug resistant fatal disease. Currently there is no validated comprehensive model of disease progression for ovarian cancer, although tremendous progress has been made in understanding the origin of this disease and a putative precursor lesion has been identified …

Proteasome Inhibition As A Potential Anti-Breast Cancer Therapy: Mechanisms Of Action And Resistance-Reversing Strategies, Rahul Rajesinh Deshmukh

Wayne State University Dissertations

AMPK activation and Ubiquitin Proteasome System (UPS) inhibition have gained great attention as therapeutic strategies for the treatment of certain types of cancers. While AMPK serves as a master regulator of cellular metabolism, UPS regulates protein homeostasis. Although the crosstalk between them is suggested, the relationship between these two important pathways is not very clear. We observed that proteasome inhibition leads to AMPK activation in human breast cancer cells. We report that a variety of proteasome inhibitors activate AMPK in all of the tested cancer cell lines. Our data using Liver Kinase B1 (LKB1)-deficient cancer cells suggests that proteasome inhibitor-induced …

Therapeutic Targeting Of Bmp2 In Nf1-Deficient Malignant Peripheral Nerve Sheath Tumors (Mpnsts), Sidra Ahsan

Wayne State University Dissertations

Neurofibromatosis type I (NF1)-deficient malignant peripheral nerve sheath tumor (MPNST) is an aggressive tumor for which the standard treatment is surgical removal with wide margins, often leaving behind cancer cells needing chemotherapy. RAS-GRD is the most widely studied functional target of NF1 implicated in tumorigenesis, however, therapeutic interventions targeting RAS activity have met with limited success. Using gene expression profiling, our lab identified BMP2-SMAD1/5/8 signaling pathway as a therapeutic target in MPNSTs, independent of the NRAS and MEK1/2 regulation. The overall goal of my research was to validate the significance of BMP2 in MPNSTs in novel cellular models, study the …

Photodynamic Therapy As An Effective Therapeutic Approach In Mame Models Of Triple Negative And Inflammatory Breast Cancers, Neha Aggarwal

Wayne State University Dissertations

Introduction: Photodynamic therapy (PDT) is a minimally invasive, FDA approved therapy for

treatment of several indications including endobronchial and esophageal cancers that are

accessible to light. Triple negative breast cancer (TNBC) and inflammatory breast cancer (IBC)

are aggressive and lethal subtypes of breast cancer that spread to chest wall and dermal

lymphatics, respectively, sites that would be accessible to light. Both TNBC and IBC patients

have a relatively poor survival rate due to lack of targeted therapies. Use of PDT is

underexplored for breast cancers but has been proposed for treatment of subtypes for which a

targeted therapy is unavailable. …

Acidic Pericellular Ph: Effects On Proteolysis And Gene Expression As Determined In 3d Models Of Breast Carcinoma, Jennifer M. Rothberg

Wayne State University Dissertations

Among the non-cellular microenvironmental factors that contribute to malignancy of solid tumors is an acidic peritumoral pH. The first objective was to determine if an acidic extracellular pH observed in vivo (i.e., pHe 6.8) affects the activity of proteases, such as cathepsin B, that contribute to degradation of collagen IV by tumor cells when grown in biologically relevant three-dimensional cultures. At pHe 6.8 there were increases in pericellular active cysteine cathepsins and in degradation of DQ-collagen IV, which was partially blocked by a cathepsin B inhibitor. Imaging probes for active cysteine cathepsins localized to tumors in vivo. The amount of …

Hedgehog Signaling: A Potential Therapeutic Target For Non-Small Cell Lung Cancer, Ma'in Yehya Maitah

Wayne State University Dissertations

The American Cancer Society estimated that 222,520 Americans were diagnosed with lung cancer and 157,300 died of lung cancer in 2010 (Jemal et al. 2009, 225-249;Jemal et al. 2011, 69-90). The clinical outcome of patients diagnosed with non-small cell lung cancer (NSCLC), the major lung cancer sub-types, is very poor, which calls for innovative research for finding novel therapeutic targets and agents for better treatment outcome.

Emerging evidences have suggested that a phenomenon called Epithelial-to-Mesenchymal Transition (EMT), which shares similar molecular characteristics with cancer stem-like cells, contributes to lung cancer treatment failure. In view of the fact that EMT process …