X-linked inhibitor of apoptosis protein mediates tumor cell resistance to antibody-dependent cellular cytotoxicity.

Loading...
Thumbnail Image

Date

2016-01-28

Journal Title

Journal ISSN

Volume Title

Repository Usage Stats

0
views
244
downloads

Citation Stats

Abstract

Inflammatory breast cancer (IBC) is the deadliest, distinct subtype of breast cancer. High expression of epidermal growth factor receptors [EGFR or human epidermal growth factor receptor 2 (HER2)] in IBC tumors has prompted trials of anti-EGFR/HER2 monoclonal antibodies to inhibit oncogenic signaling; however, de novo and acquired therapeutic resistance is common. Another critical function of these antibodies is to mediate antibody-dependent cellular cytotoxicity (ADCC), which enables immune effector cells to engage tumors and deliver granzymes, activating executioner caspases. We hypothesized that high expression of anti-apoptotic molecules in tumors would render them resistant to ADCC. Herein, we demonstrate that the most potent caspase inhibitor, X-linked inhibitor of apoptosis protein (XIAP), overexpressed in IBC, drives resistance to ADCC mediated by cetuximab (anti-EGFR) and trastuzumab (anti-HER2). Overexpression of XIAP in parental IBC cell lines enhances resistance to ADCC; conversely, targeted downregulation of XIAP in ADCC-resistant IBC cells renders them sensitive. As hypothesized, this ADCC resistance is in part a result of the ability of XIAP to inhibit caspase activity; however, we also unexpectedly found that resistance was dependent on XIAP-mediated, caspase-independent suppression of reactive oxygen species (ROS) accumulation, which otherwise occurs during ADCC. Transcriptome analysis supported these observations by revealing modulation of genes involved in immunosuppression and oxidative stress response in XIAP-overexpressing, ADCC-resistant cells. We conclude that XIAP is a critical modulator of ADCC responsiveness, operating through both caspase-dependent and -independent mechanisms. These results suggest that strategies targeting the effects of XIAP on caspase activation and ROS suppression have the potential to enhance the activity of monoclonal antibody-based immunotherapy.

Department

Description

Provenance

Citation

Published Version (Please cite this version)

10.1038/cddis.2015.412

Publication Info

Evans, MK, SJ Sauer, S Nath, TJ Robinson, MA Morse and GR Devi (2016). X-linked inhibitor of apoptosis protein mediates tumor cell resistance to antibody-dependent cellular cytotoxicity. Cell Death Dis, 7. p. e2073. 10.1038/cddis.2015.412 Retrieved from https://hdl.handle.net/10161/12402.

This is constructed from limited available data and may be imprecise. To cite this article, please review & use the official citation provided by the journal.

Scholars@Duke

Morse

Michael Aaron Morse

Professor of Medicine

We are studying the use of immune therapies to treat various cancers, including gastrointestinal, breast, and lung cancers and melanoma. These therapies include vaccines based on dendritic cells developed in our laboratory as well as vaccines based on peptides, viral vectors, and DNA plasmids. Our group is also a national leader in the development and use of laboratory assays for demonstrating immunologic responses to cancer vaccines. Finally, we are developing immunotherapies based on adoptive transfer of tumor and viral antigen-specific T cells.

Our current clinical trials include phase I and II studies of immunotherapy for: patients with metastatic malignancies expressing CEA, pancreatic cancer, colorectal cancer, breast cancer, and ovarian cancer, and leukemias following HSCT. My clinical area of expertise is in gastrointestinal oncology, in particular, the treatment of hepatic malignancies, and malignant melanoma.

Key words: dendritic cells, immunotherapy, vaccines, T cells, gastrointestinal oncology, melanoma, hepatoma

Devi

Gayathri R. Devi

Professor in Surgery

Dr. Devi’s research interests include functional genomics, anti-cancer drug discovery and development, mechanisms of cancer cell signaling, tumor immunity and applications thereof for overcoming therapeutic resistance in cancer.

The lab has established prostate, inflammatory breast cancer and ovarian cellular and tumor models.


Unless otherwise indicated, scholarly articles published by Duke faculty members are made available here with a CC-BY-NC (Creative Commons Attribution Non-Commercial) license, as enabled by the Duke Open Access Policy. If you wish to use the materials in ways not already permitted under CC-BY-NC, please consult the copyright owner. Other materials are made available here through the author’s grant of a non-exclusive license to make their work openly accessible.