Laboratory and Basic Science Research Commons^™

Sustained Adrenergic Signaling Promotes Cervical Cancer Progression, Nouara C. Sadaoui

Dissertations and Theses (Open Access)

Background: Chronic stress and sustained adrenergic signaling are known to promote tumor progression. The underlying mechanisms behind this process are not well understood. We examined the effects of sustained adrenergic signaling on cervical cancer progression through increased expression of HPV oncogenes, E6 and E7.

Materials and Methods: ADRβ expression levels were examined in patient-derived cervical cancer samples. We used an orthotopic model of cervical cancer to investigate the effects of restraint stress on tumor growth and metastasis. We evaluated the in vivo effects of a β-blocker, propranolol, and HPV E6/E7 siRNA. In vitro, ADRβ positive cervical cancer cells were …

Mdm2-Mediated Degradation Of Sirt6 Phosphorylated By Akt1 Promotes Tumorigenesis And Trastuzumab Resistance In Breast Cancer, Umadevi Thirumurthi

Dissertations and Theses (Open Access)

Sirtuin6 (SIRT6) is one of the members of the Sirtuin family and functions as a longevity assurance gene by promoting genomic stability. It also regulates various cancer-associated pathways and was recently established as a bonafide tumor suppressor in colon cancer. This suggests that SIRT6 is an attractive target for pharmacological activation in cancer treatment, and hence, identification of potential regulators of SIRT6 would be an important and critical contribution towards cancer treatment. Here, we show that AKT1 phosphorylates SIRT6 at Ser³³⁸ and induces MDM2-SIRT6 interaction, priming SIRT6 for degradation via the MDM2-dependent ubiquitin-proteasome pathway. Blocking SIRT6 Ser³³⁸ phosphorylation …

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 …

Novel Biomarkers Can Be Used As Targets To Combat Cancer, Harini Krishnan

Graduate School of Biomedical Sciences Theses and Dissertations

Cancer kills almost 8 million people per year worldwide. Therefore, about 13 people die from cancer every minute. Clearly, current cancer treatments are not completely effective. Moreover, many chemotherapeutic reagents are not very specific for cancer cells.

These agents attack rapidly dividing cells, including a wide array of normal cells, in addition to cancer cells, in the body. This lack of specificity can cause collateral damage and significant side effects in patients. More targeted therapies are needed to successfully combat cancer. Specific cancer biomarkers need to identified and characterized in order to develop better targeted anti-cancer drugs.

Tumor cells can …

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 …

Analysis Of The Regulation And Function Of Cip2a To Identify Candidate Biomarkers For Prostate Cancer, Diana Savoly

Graduate School of Biomedical Sciences Theses and Dissertations

Protein Phosphatase 2A (PP2A) is a tumor suppressor involved in the regulation of several signaling pathways and the cell cycle. PP2A becomes inactivated by several inhibitors, including Cancerous Inhibitor of PP2A (CIP2A). CIP2A has been identified as an oncogene, which is over-expressed in cancers and inhibits PP2A through direct interaction. CIP2A is recognized as a biomarker for cancer; however, it is not cancer-specific. Therefore, we identified and examined the use of CIP2A-regulated proteins as potential biomarkers in prostate cancer to better diagnose prostate cancer in patients. Currently, Prostate Specific Antigen (PSA) is widely used to detect prostate cancer; however, it …

The Role Of Mammalian Cyclin C In Stress Response And Thyroid Disease Progression, Kun Wang

Graduate School of Biomedical Sciences Theses and Dissertations

The cellular response to stress involves changes in gene expression programs as well as the remodeling of subcellular organelles including the mitochondria. Important for this study, the mitochondria undergo extensive fragmentation when the cell is exposed to a variety of stressors. The cyclin C-Cdk8 kinase is a highly conserved transcription factor that associates with the RNA polymerase II holoenzyme. Using cyclin C knockout (CCNC^-/-) mouse embryonic fibroblast (MEF) cells, I revealed that cyclin C is required for the extensive mitochondrial fragmentation following treatment with pro-oxidants or the anti-cancer drug cisplatin. However, Cdk8 is not required for this process …

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 …

Purification And Characterization Of Oxidation-Resistant Ribonuclease Inhibitor Variants, Alec W. Uebersohn

Lawrence University Honors Projects

Ribonuclease inhibitor (RI) is an intracellular mammalian protein which binds vertebrate-specific ribonucleases; this interaction is one of the tightest non-covalent interactions yet discovered. The biological activity of RI is poorly understood, but it is thought to regulate the biological functions of ribonucleases, which include initiating blood vessel growth, maintaining neuron viability, attacking pathogens, and mediating cell stress responses. RI is also involved in pathways unrelated to ribonucleases, including interactions with Drosha and PTEN, an anti-tumor protein.

One of the defining characteristics of RI is its oxidation sensitivity, a result of its unusually high cysteine content. The oxidation of RI is …

Lmw-E Mediates Mammary Tumorigenesis By Deregulating Acinar Morphogenesis & Generating Cancer Stem Cells, Mylinh T. Duong

Dissertations and Theses (Open Access)

Cyclin E is the regulatory subunit of the cyclin E/CDK2 complex that

mediates the G1-S phase transition. N-terminal cleavage of cyclin E by elastase in

breast cancer generates two low molecular weight (LMW) isoforms that exhibit both

enhanced kinase activity and resistance to p21 and p27 inhibition compared to fulllength cyclin E. Clinically, approximately 27% of breast cancer patients overexpress

LMW-E and associate with poor survival. Therefore, we hypothesize that LMW-E

disrupts normal mammary acinar morphogenesis and serves as the initial route into

breast tumor development. We first demonstrate that LMW-E overexpression in

non-tumorigenic hMECs is sufficient to induce tumor …

Increased Geranylgeranylated K-Ras Contributes To Antineoplastic Effects Of Farnesyltransferase Inhibitors., Mandy A. Hall

Dissertations and Theses (Open Access)

The Ras family of small GTPases (N-, H-, and K-Ras) is a group of important signaling mediators. Ras is frequently activated in some cancers, while others maintain low level activity to achieve optimal cell growth. In cells with endogenously low levels of active Ras, increasing Ras signaling through the ERK and p38 MAPK pathways can cause growth arrest or cell death. Ras requires prenylation – the addition of a 15-carbon (farnesyl) or 20-carbon (geranylgeranyl) group – to keep the protein anchored into membranes for effective signaling. N- and K-Ras can be alternatively geranylgeranylated (GG’d) if farnesylation is inhibited but are …

Effects Of Liposome-Encapsulated Tnf-Alpha And Radiation Against Colon Cancer, Dong Won Kim

Loma Linda University Electronic Theses, Dissertations & Projects

Previous studies have shown that tumor necrosis factor-α (TNF-α) can augment the antitumor effects of radiation, inhibiting tumor progression to a greater extent than either modality alone. However, nonspecific toxicities associated with TNF-α have limited its use as an adjuvant. This limitation is potentially resolved with the encapsulation of TNF-α in sterically stabilized, PEGylated liposomes (STEALTH®). Thus, the overall hypothesis of the research was that the combination of radiation with STEALTH® liposome encapsulated TNF-α (SL-TNF-α) will have greater efficacy and fewer dose-limiting side effects in the LS174T human colorectal tumor xenograft model compared to the combination of free TNF-α and …