DOI

10.17077/etd.ozas-ciug

Document Type

Dissertation

Date of Degree

Fall 2018

Access Restrictions

Access restricted until 01/31/2020

Degree Name

PhD (Doctor of Philosophy)

Degree In

Free Radical and Radiation Biology

First Advisor

Simons-Burnett, Andrean

First Committee Member

Gibson-Corley, Katherine

Second Committee Member

Spitz, Douglas R.

Third Committee Member

Weiner, George

Fourth Committee Member

Zhang, Weizhou

Abstract

Despite the incorporation of the epidermal growth factor receptor (EGFR) inhibitor cetuximab into the clinical management of recurrent and metastatic (R/M) head and neck squamous cell carcinoma (HNSCC), only a small subset of patients responds to cetuximab, despite EGFR overexpression in virtually all of their tumors. At this time, there is a lack of validated predictive biomarkers to predict which patients will respond to cetuximab. Our previous work suggests that cetuximab activates the interleukin-1 (IL-1) pathway via tumor release of IL-1 alpha (IL-1α), although the implications of activating this pathway are unclear. The IL-1 pathway plays a central role in immune response and displays both pro-tumor and anti-tumor activities. IL-1 may promote tumor growth by upregulating the secretion of pro-inflammatory mediators involved in angiogenesis and metastasis. On the other hand, IL-1 signaling may promote antitumor immunity via enhancement of natural killer (NK)-cell mediated antibody-dependent cell-mediated cytotoxicity (ADCC) and T cell activity, which are important mechanisms of action of cetuximab.

The goal of this work is to determine how modulation of the IL-1 pathway affects HNSCC tumor response to cetuximab and if IL-1 may serve as a predictive biomarker for patient response to cetuximab. Blockade of IL-1 signaling did not enhance the anti-tumor efficacy of cetuximab, while IL-1α overexpression and treatment with recombinant IL-1α and IL-1α nanoparticles increased HNSCC tumor response to cetuximab in immunodeficient and immunocompetent HNSCC mouse models. Mechanistically, these results appear to be due to activation of an anti-tumor NK and T cell-mediated immune response. Additionally, we found that both nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) and inducible nitric oxide synthase (iNOS) activity may be involved in the efficacy of IL-1-induced ADCC against cetuximab-coated HNSCC cells. Altogether, these results suggest that IL-1 signaling is necessary for HNSCC tumor response to cetuximab. Furthermore, we have shown that pre-treatment serum and tumor IL-1 ligands can predict progression-free survival of HNSCC patients treated with standard-of-care cetuximab and chemotherapy, cetuximab combined with other targeted therapies, and cetuximab monotherapy. Overall, we propose that IL-1α warrants further study as a novel therapeutic to enhance response to cetuximab and as a predictive biomarker for HNSCC response to cetuximab.

Keywords

cetuximab, HNSCC, Interleukin-1

Pages

x, pages

Bibliography

Includes bibliographical references (pages 98-118).

Copyright

Copyright © 2018 Madelyn Espinosa-Cotton

Available for download on Friday, January 31, 2020

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