Targeting and Sensitization of Breast Cancer Cells to Killing with a Novel Interleukin-13 Receptor α2-Specific Hybrid Cytolytic Peptide

Riaz Jannoo; William Walker; Venkateswarlu Kanamarlapudi

doi:10.3390/cancers15102772

Targeting and Sensitization of Breast Cancer Cells to Killing with a Novel Interleukin-13 Receptor α2-Specific Hybrid Cytolytic Peptide

Cancers (Basel). 2023 May 16;15(10):2772. doi: 10.3390/cancers15102772.

Authors

Riaz Jannoo¹, William Walker², Venkateswarlu Kanamarlapudi²

Affiliations

¹ UCL ECMC GCLP Facility, UCL Cancer Institute, University College London, London WC1E 6DD, UK.
² Institute of Life Science, School of Medicine, Swansea University, Singleton Park, Swansea SA2 8PP, UK.

Abstract

Highly metastatic breast cancers, such as triple-negative subtypes (TNBC), require the most effective treatments. Since interleukin-13 receptor (IL-13R)α2 is reportedly over-expressed in some cancers, we investigated here its expression and the feasibility of therapeutically targeting this receptor in breast cancer using a novel hybrid cytolytic peptide (Pep-1-Phor21) consisting of IL-13Rα2-binding (Pep-1) and cytolytic (Phor21) domains. This study demonstrates that particularly TNBC tissues and cells display the prominent expression of IL-13Rα2. Furthermore, Pep-1-Phor21 induced the rapid necrosis of tumor cells expressing cell-surface IL-13Rα2. Notably, IL-13Rα2 expression was found to be epigenetically regulated in breast cancer cells in that the inhibition of histone deacetylase (HDAC) or DNA methyltransferase (DNMT) upregulated IL-13Rα2 expression, thereby sensitizing them to Pep-1-Phor21. IL-13Rα2-negative non-malignant cells were refractory to these epigenetic effects. Consistent with its cytolytic activity, Pep-1-Phor21 readily destroyed IL-13Rα2-expressing breast cancer spheroids with HDAC or DNMT inhibition, further enhancing cytolytic activity. Therefore, the Pep-1-Phor21-mediated targeting of IL-13Rα2 is a potentially novel therapeutic strategy for TNBC. Given that tumor cells can be selectively sensitized to Pep-1-Phor21 via the epigenetic up-regulation of IL-13Rα2, a combined adjuvant approach involving Pep-1-Phor21 and epigenetic inhibitors may be an effective strategy.

Keywords: IL-13Rα2; TNBC; adjuvant; cancer therapy; cytolytic peptide; cytotoxic; epigenetic.

Grants and funding

This research received no external funding. R.J.’s Ph.D. studentship was funded by Knowledge Economy Skills Scholarships (KESS) from European Social Fund.