The Biological and Immunological Effects of Irreversible Electroporation and Combination Therapy Options for the Improving the Treatment of Pancreatic Cancer

While cancer treatments have advanced for multiple cancers, pancreatic cancer remains a lethal cancer with few therapy options available. This is due to the inaccessibility of the tumor by surgical and thermal ablative means, high potential for chemoresistance and metastasis, and strongly immunosuppressive tumor microenvironment that makes new treatment measures ineffective in clinic. Irreversible electroporation (IRE) utilizes short, high voltage electrical pulses to form microlesions in cell membranes and induce cell death. While IRE has had significant impact in pancreatic cancer treatment in clinical trials, little is known on the biological and immunological effects of IRE on pancreatic cancer. By studying the effects of IRE on pancreatic tumor biology and the host immune system, I hypothesize I can identify potential combination therapy targets for IRE. I utilized in vitro, ex vivo, and in vivo animal models of both human and murine cancer to study the effects of IRE on pancreatic cancer progression and its potential for immunomodulation. My findings have shown that IRE can significantly delay cancer progression by inducing necroptosis in the tumor and altering the tumor microenvironment by increasing inflammatory signaling. IRE can also produce viable antigens for presentation to induce local and systemic immunosurveillance. However, these effects are limited by countering expression of programmed-cell death ligand 1 (PD-L1), a checkpoint protein that inhibits cytotoxic lymphocyte activity and allows the tumors to recur. The effects of IRE can therefore be expanded by multiple combination therapy approaches, such as chemotherapeutic application (potentially with nanoparticle packaging), PD-1/PD-L1 antibody immunotherapies, and small molecule inhibitors directed at tumor growth signaling that previously showed limited efficacy in clinic.

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Translational Biology, Medicine and Health

Department dc:contributor.department

Graduate School

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2020

Author dc:creator

• Brock, Rebecca Michaela

Chair dc:contributor.committeechair

• Allen, Irving C.

Committee members dc:contributor.committeemember

• Davalos, Rafael V.
• Schmelz, Eva M.
• Dervisis, Nikolaos G.
• Oestreich, Kenneth

• oncology
• immunology
• biomedical
• cancer
• inflammation

Statement dc:rights

• Creative Commons Attribution 4.0 International

Licence dc:rights.uri

• http://creativecommons.org/licenses/by/4.0/

Dc Identifier Other

vt_gsexam:25741

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/98775