Life Sciences Commons^™

Impact Of Intratumor Heterogeneity And The Tumor Microenvironment In Shaping Tumor Evolution And Response To Therapy, Akash Mitra

Dissertations & Theses (Open Access)

Intratumor heterogeneity (ITH) is a crucial challenge in cancer treatment. The genotypic and phenotypic heterogeneity underlying diverse cancer types leads to subclonal variation, which may result in mixed or failed response to therapy. The heterogeneity at the tumor level, along with the tumor microenvironment (TME), often shapes tumor evolution and ultimately clinical outcome. Given that modern treatment paradigms increasingly expose patients with metastatic disease to multiple treatment modalities through the course of their disease, there exists a need to characterize robust and predictive biomarkers of response to therapy. In order to accurately characterize tumor evolution, we need to account for …

Elucidating The Roles Of Il-15 In The Tumor Microenvironment, Rosa Maria Santana Carrero

Dissertations & Theses (Open Access)

ELUCIDATING THE ROLES OF IL-15 IN THE TUMOR MICROENVIRONMENT

Rosa M. Santana Carrero, B.S.

Advisory Professors: Shao-Cong Sun, Ph.D. & Kimberly S. Schluns, Ph.D.

Interleukin-15 (IL-15) is a factor that promotes activation, proliferation, cytotoxicity, and survival of CD8 T cells and NK cells, and has been shown to have anti-tumor effects. Moreover, loss of IL-15 expression in human colorectal tumors correlates with increased risk of relapse, diminished survival, decreased density and proliferation of T cells. All together these findings suggest that IL-15 expressed locally in the tumor microenvironment (TME) is an important mediator of anti-tumor responses by tumor infiltrating lymphocytes …

Micrornas Associated With Melanoma Inflammation And Response To Pd-1 Inhibition, Robert Szczepaniak Sloane

Dissertations & Theses (Open Access)

Melanoma is an aggressive malignancy of melanocytes with historically poor outcomes. Melanoma therapy has improved markedly over the past decade with advances in molecularly targeted agents and immunotherapies. Immune checkpoint inhibitors achieve T-cell mediated anti-tumor efficacy by blocking engagement of inhibitory checkpoints on T-cells to overcome immunosuppressive signals from tumor cells and the broader microenvironment. Despite these advances, there are a significant proportion of patients who do not benefit from existing immunotherapy strategies making it a priority to identify and target the mechanisms that confer resistance to therapy. We demonstrate that microRNAs are accurate markers of microenvironment composition with prognostic …

Il-1Α Blockade Reduces Immune Suppression In The Early Tumor Micro-Environment, Brenda Melendez

Dissertations & Theses (Open Access)

IL-1α Blockade Reduces Immune Suppression in the Early Tumor Micro-Environment

Brenda Melendez, B.S.

Advisory Professor: Gregory Lizee, PhD.

Immunotherapy against melanoma has shown great promise in the clinic for treating advanced-stage patients. However, a major barrier against effective T cell mediated cytotoxicity is immunosuppression in the tumor micro-environment. It has been described that tumors secrete pro-inflammatory cytokines capable of modulating immune responses that favors the growth of tumor cells. Specifically, IL-1 plays a critical role in myeloid cell recruitment and activation, which can in turn inhibit T cell activity in vivo. Moreover, IL-1 is also known to up-regulate immune inhibitory …

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

Dissertations & 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 …