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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
171

Loss of TIP30 Accelerates Pancreatic Cancer Progression and Metastasis

Imasuen Williams, Imade E. 07 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Pancreatic ductal adenocarcinoma (PDAC) is currently the fourth leading cause of cancer-related death in the United States, and is characterized by key driver mutations (e.g. KRAS, TP53, CDKN2A, and SMAD4), elevated expression of growth factors such as TGF-βs and the EGF receptor (EGFR), a markedly desmoplastic stroma, and a propensity to develop multi-organ metastases and chemoresistance. Consistent with its aggressive nature, the 5-year survival rate for PDAC is 8-9%, which demonstrates an urgent need to develop novel therapies. High expression levels of microRNA-10b (miR-10b) in PDAC tissues are associated with decreased patient survival and earlier appearance of metastatic disease following neoadjuvant chemoradiotherapy. miR-10b downregulates the expression of transcription coactivator Tat-Interacting Protein 30 (TIP30) by targeting its 3’UTR. TIP30 has multiple reported functions. TIP30 suppresses tumor formation and metastasis, forms a complex that regulates EGFR trafficking and degradation, and transcriptionally upregulates pro-apoptotic genes. Alterations in TIP30 have been reported in multiple human cancers, including pancreatic cancer. We hypothesized that Tip30-deficiency accelerates PDAC progression and metastasis in a murine model of PDAC. To test this hypothesis, we crossed mice with oncogenic Kras (KC) localized to the pancreas epithelium, with Tip30-deficient mice (K30C). We compared PDAC histopathology between Tip30-heterozygous (K30+/-C) and Tip30-null (K30-/-C) mice. Tip30-heterozygosity accelerated PDAC-lesion-associated pancreatic cancer cell (PCC) pulmonary seeding. By contrast, total loss of Tip30 enhanced PCC micrometastatic seeding to the liver and hepatic metastasis. K30+/-C mice also presented with an early, increased penetrance of lung lesions and lung adenocarcinoma; and PCCs isolated from K30+/-C pancreata exhibited increased EGFR protein levels. These findings suggest that TIP30 deficiency can have a dose-dependent effect on organotropic metastasis and EGFR levels in PCCs. Future studies will delineate the molecular consequences of TIP30 loss in PDAC and contribute to a broader understanding of pancreatic cancer metastasis. / 2020-08-05
172

Investigating Potential Bioactive Compounds from Rhodococcus and Their Effects on MCF7 Breast Cancer Cells

Crabtree, Megan N 01 December 2013 (has links) (PDF)
Many drugs used in the treatment of various cancers are derived from or influenced by compounds from nature. The soil bacterium Rhodococcus is of interest because of its identified secondary metabolic pathways and the production of novel natural antibiotics from several strains. In this study, a solid agar extraction method was used to collect compounds from strains of Rhodococcus. These bacterial compound extracts were then tested using a MTT assay in order to evaluate their effectiveness in augmenting MCF7 breast cancer cell death. The results of two way ANOVA analyses revealed 18 compound extracts from 15 strains of Rhodococcus that showed significant p-values when assayed with MCF7 breast cancer cells but nonsignificant interaction p-values when assayed with the healthy cell control. These results prompt further identification of specific compounds present in the bacterial extract that caused cell death as well as a mechanism of interaction with the breast cancer cells.
173

Prostasin Is Expressed In Benign Prostatic Hyperplasia And Regulates Cell Proliferation And Invasion Via Inos, Icam-1, And Cycli

Hatfield, Meghan 01 January 2008 (has links)
Prostasin is expressed in normal prostate epithelial cells but down-regulated in prostate cancers, while prostasin re-expression in invasive prostate cancer cells reduced invasion. We examined prostasin expression and function in benign prostatic hyperplasia (BPH). We evaluated prostasin expression in 12 BPH specimens by immunohistochemistry, and evaluated the impact of prostasin silencing by siRNA on the expression of the inducible nitric oxide synthase (iNOS), intercellular adhesion molecule-1 (ICAM-1), and cyclin D1, as well as on cell proliferation and invasion, using the BPH-1 human prostate epithelial cell line model. Prostasin expression was localized in the glands of BPH tissues by immunohistochemistry, in either the tall columnar-shaped or the flattened epithelial cells. We silenced prostasin expression by >50% at both the mRNA and protein levels using siRNA in the BPH-1 human prostate epithelial cell line, and this silencing of prostasin expression was associated with an induction of iNOS and ICAM-1 expression and a down-regulation of cyclin D1 expression. The protein expression of EGFR, a putative prostasin substrate, was not affected by prostasin silencing in this cell line. The prostasin-silenced cells displayed a reduced cell proliferation rate and reduced invasiveness, cell behaviors regulated by cyclin D1, iNOS, and ICAM-1 in the BPH-1 cells. We believe that this down-regulation of cyclin D1 is due to prostasin's augmentative effect on iNOS. We also believe that the decrease in cell motility is due to an increase in iNOS and ICAM-1 as well as a decrease in cyclin D1, since all of these molecules can play a role in cell motility. In conclusion, Prostasin is somehow involved in the regulation of inflammatory gene expression (iNOS and ICAM-1) in prostate epithelial cells, as well as cyclin D1 expression, cell proliferation and invasion, involving molecular mechanisms different than those in the prostate cancer cells. These studies suggest that prostasin is a player in the glandular components of benign prostatic hyperplasia.
174

Role Of Transient Receptor Potential Canonical-6 (trpc6) Channel In Metastasis Of Glioblastoma Multiforme

Venkataraman, Rajarajeshwari 01 January 2008 (has links)
Glioblastoma multiforme (GBM) is one of the extremely fatal brain tumors. The main reason that makes it so lethal is its capability to invade and spread to other parts of CNS producing secondary tumors. Among other factors hypoxia, reduced oxygen availability, is linked to higher metastatic potential of cancers. Hypoxia causes numerous changes in genome and proteome of the cell. These changes help a normal cell to adapt to nutritional deficiency, but the same changes can increase the malignancy and metastasis in tumor cells. Extensive research by a number of curious scientists reveal that various pathways involving numerous proteins cross-talk and interact with each other and execute a response to hypoxia. We are trying to establish the link between two such pathways HIF1-alpha pathway and Notch pathway. Both, HIF1-alpha, which is a transcription factor that becomes active in hypoxic conditions and Notch, which is an evolutionarily conserved cell-fate determinant, are implicated in hypoxia-induced metastasis of cancer. In this given project, we confirm the cross talk between Notch and HIF1-alpha pathway and further continue our study to show that TrpC6 is the downstream mediator of this pathway, leading to metastasis of GBM. Expression analysis of hypoxia-induced U373 cells (Grade 3 glioblastoma cells), using Real-time PCR, western blot and immunocytochemistry, revealed elevated levels of Notch, Hif1 and TrpC6 indicating that these proteins might be important for the cellular response to hypoxia. Blocking Notch and/or HIF1-alpha, either by DAPT or HIF1-inhibitor, confirmed the communication between these two pathways. Role of TrpC6 in metastasis was demonstrated by knocking down this gene using siRNA against TrpC6. Inhibition of TrpC6 markedly decreased cell proliferation, migration, angiogenesis and tumorigenesis in these hypoxia-induced Glioblastoma cells. In summary, all these results reveal that TrpC6 is indeed an important member of the Notch-mediated metastasis of Glioblastoma under hypoxic conditions. This role of TrpC6 can therefore be utilized for pharmacological intervention to prevent hypoxia-induced metastasis in GBM.
175

The Relationship between Inflammatory Diet Score and Cancer Outcomes: Systematic Review and Meta-Analysis

Han, Eric 01 January 2022 (has links) (PDF)
Cancer remains one of the most prevalent diseases in the United States and a leading cause of death. Large prospective studies have found significant correlations between dietary intake and cancer. Chronic inflammation promotes pro-cancer inflammatory environments promoting the formation and growth of tumors while preventing effective anti-tumor responses. Nutrition can impact inflammation, with the intake of certain food items increasing biomarkers for systemic inflammation thus, the objective of this research was to explore the relationship between inflammatory diet score measured by the Dietary Inflammatory index and all-cause mortality, cancer-specific mortality, and cancer recurrence among cancer survivors. Web of Science, Medline, CINHAL, and PsycINFO databases were searched to collect potentially eligible sources that focus on dietary inflammation and cancer outcomes. All sources were uploaded to Covidence software and screened by two independent blinded reviewers. The quality of the sources was assessed using the Newcastle Ottawa scale and relevant data was extracted and transferred to the Comprehensive Meta Analysis software and a random effects model was used to perform meta-analysis. Of the 1444 studies imported into the Covidence software, 13 passed all the screening stages and were included in the final analysis. Eight studies reported on pre-diagnosis diet while five others reported on post-diagnosis diet. Five studies reported on colorectal cancer, four on breast cancer, two on ovarian cancer, one on endometrial cancer and one on prostate cancer. Meta-analysis of the studies found that being in the highest postdiagnosis DII score indicating pro-inflammatory diet significantly increased the risk of all-cause death among cancer survivors by 33.5% (HR = 1.335, 95% CI = 1.049, 1.698, n = 6). Analysis did not show a statistically significant association between DII score and cancer mortality or recurrence (HR = 1.097, 95% CI = 0.939, 1.281, n = 6). Analysis by cancer subtype found a significant correlation between postdiagnosis DII score and all-cause mortality among the breast cancer survivors (HR = 1.335, 95% CI = 1.041, 1.711, n = 3) though there were no significant associations between DII and the outcomes of interest from the other cancer types. The meta-analysis concludes that being in the highest postdiagnosis DII score group significantly increased the risk of all-cause death among cancer survivors. This suggests that risk of all-cause mortality could be reduced for cancer survivors by consuming more anti-inflammatory food components and reducing consumption of pro-inflammatory foods. These findings also warrant more research in this field to clarify the relationship between dietary inflammation as measured by the DII and cancer outcomes, particularly cancer-specific mortality.
176

Screening for Anticancer Agents to Inhibit Mitotic Kinases and Proliferation of Metastatic Prostate Cancer Cells

Nguyen, Khoa 01 January 2016 (has links)
Current treatments for prostate cancer (PCa) are marred with high relapse frequency and development of progressively aggressive cancers; developing new treatment options for PCa remains crucial. In this project, a series of synthetic compounds based on natural products will be screened to identify inhibitors for Aurora-A kinase (Aur-A). Aur-A facilitates centrosome separation and bipolar spindle formation during mitosis. Aur-A is overexpressed in metastatic PCa cells, and is a good candidate for targeted therapies. Compound libraries are designed using natural compounds that contain simple structural elements as starting points for developing drug like libraries. High-throughput screening of these libraries will be used to identify potent antimitotic agents that selectively affect cancer cells but not normal cells. A combination of in vitro protein assays – quantifying protein activity – cell-based assays – measuring cell growth and proliferation – and cell-reporter assays – to determine which metabolic pathway the compound affects – were used to identify potential inhibitors. Through these methods, we have identified several compounds, with special consideration to thiazole piperazine compounds, to successfully inhibit proliferation of metastatic PCa cells.
177

A Novel Drug to Induce Apoptosis in Advanced Prostate Cancer Cells

Sanghvi, Parshva A 01 January 2022 (has links)
Prostate cancer is one of the leading causes of death for men in America as approximately 1 in 41 men will have prostate cancer. In this research, we focus on enzalutamide-resistant prostate cancer cells as cell resistance to enzalutamide is a prevalent obstacle in treating prostate cancer. We tested a novel compound library at different doses and observed each compound's efficacy in inducing apoptosis in enzalutamide-resistant cells. Furthermore, we analyzed the mechanism by which apoptosis was induced in compounds that showed a high efficacy at lower doses. Overall, we found that Darapladib shows promising results in treating cells that have acquired enzalutamide resistance.
178

Role of PTPRT in obesity and its substrate paxillin tyrosine-88 in colorectal cancer

Scott, Anthony January 2014 (has links)
No description available.
179

Regulation of p53, p21, ARF, BIM, and BAX by the Transcription Factor Trip-Br1

Lehmkuhl-Dakhwe, K. Virginia January 2007 (has links)
No description available.
180

Investigation of a novel small molecule TRAIL inducer, ONC201: pre-clinical anti-cancer efficacy, anti-metastasis effects, tumor immunity; and the structure-activity relationships (SAR) and mechanism of action of potential analogues

Wagner, Jessica Michelle January 2018 (has links)
ONC201 is a novel compound that upregulates endogenous TNF-Related Apoptosis-Inducing Ligand (TRAIL), in tumor and normal cells, restoring autocrine and paracrine anti-tumor activity within tumor cells, and upregulates the DR5 gene by activating the integrated stress response, inducing eIF2-alpha-dependent ATF4 and CHOP [1-3]. ONC201 also demonstrates potent anti-tumor effects on colorectal cancers [4, 5]. ONC201 presented a promising oral bioavailability, wide distribution throughout the body, and ability to cross the blood-brain barrier. Further, the unique ability of its TRAIL-and-DR5-based signaling to induce apoptosis in cancer cells and not normal cells adds to its appeal as an anti-cancer therapeutic and prompted clinical development [1-4, 6]. ONC201 has successfully completed an FDA advanced Phase I/II clinical trial in advanced aggressive refractory solid tumors. Results indicated that ONC201 is well-tolerated and recommended a phase II dose of 625 mg orally every 3 weeks. Several Phase I/II clinical trials are enrolling in multiple solid tumors and hematological malignancies [7, 8]. Chapter two of this study provides evidence that ONC201 dose intensification demonstrates an increased pharmacodynamic effect and an increasing anti-tumor efficacy in vivo while having a safe toxicity profile upon weekly dosing. This data influenced the Phase II clinical trials, which have now been adjusted to include weekly dosing. Given the potential anti-metastatic effects of TRAIL signaling and the role of TRAIL in the immune surveillance of cancer, we hypothesized that ONC201 would suppress metastatic tumor development and engage the immune system in its anti-cancer activity. We also establish that ONC201 provides an important anti-metastatic effect in CRC that should be pursued in both pre-clinical and clinical studies. Tail vein and surgical CRC models demonstrate that ONC201 inhibits the number and size of metastases. Evidence has shown that TRAIL can also inhibit cancer metastasis by possibly inducing cell death or TRAIL-sensitization in the primary tumor when cells undergo extravasation upon detachment from the primary tumor [9-11]. While we show that TRAIL plays a role in ONC201’s ability to inhibit migration/invasion in vitro, further investigation of the role of TRAIL in vivo is necessary. Our data indicates that ONC201 promotes a pro-immune response in CRC subcutaneous tumors with increased NK cells that play a role in ONC201’s efficacy in syngeneic models. Since activated natural killer cells express TRAIL, we established that ON201 can activate and induce TRAIL expression in NK cells [12, 13]. As we did not find any immune infiltrates in the metastases, we suggest that the effect of the micro-environment or in more clinically-relevant models with stromal environments should be pursued. Chapter 3 of this of thesis demonstrates the characterization of ONC201’s core structure and development of ONC201 analogues including their mechanistic differences and potential in vivo efficacy and safety. We have demonstrates the importance of the angular structure of ONC201 to ONC201’s anti-tumor efficacy [14]. The novel pharmacophore has now been called as imipridone and is essential for its anti-tumor activity, as the linear isomer had no anti-tumor effect. We leveraged this unique pharmacophore to synthesize ONC201 analogues with distinct therapeutic properties; namely, targeting ONC201-resistant tumor types or possessing distinct signaling properties. Imipridone R2 analogues have a lower IC50 and are more promising than their lead compound in certain tumor types. ONC212, a halide R2 analogue, demonstrates superior efficacy in vivo in melanoma xenografts, a large therapeutic window; but does have a rapid PK. Oncoceutics is currently developing ONC212 for a first-in human Phase I clinical trial. The fourth chapter of this study demonstrates the potential of a combinational therapy with ONC201 in colorectal cancer with bevacuzimab. Clinical trials in CRC and other tumor types have demonstrated that therapeutics targeting the vascular endothelial growth factor (VEGF) pathway, such as bevacizumab, are effective in combination with certain chemotherapeutic agents. ONC201 in combination with bevacuzimab led to superior results with almost no tumor growth. This result was re-capitulated in syngeneic models. Given that bevacuzimab is approved for metastatic CRC, we suggest that ONC201 in combination with bevacuzimab should be introduced into a combinatorial Phase II clinical trial. This thesis focuses on the importance of dose-intensification of ONC201 on its pre-clinical efficacy; establish an anti-metastatic effect; demonstrate an immune increase in subcutaneous models; and elucidate the role of the core angular structure in efficacy with the development novel ONC201 analogues. The importance of pre-clinical studies, ONC201’s analogues including the successful development of ONC212, and potentially advantageous combinational therapies with anti-angiogenics is explained in the chapters throughout. / Cancer Biology & Genetics

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