Inhibition of IκB Kinase Is a Potential Therapeutic Strategy to Circumvent Resistance to Epidermal Growth Factor Receptor Inhibition in Triple-Negative Breast Cancer Cells

• Published in: Cancers Vol. 14; no. 21; p. 5215
• Main Authors: Yi, Yong Weon, You, Kyu Sic, Han, Sanghee, Ha, In Jin, Park, Jeong-Soo, Lee, Seok-Geun, Seong, Yeon-Sun
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 24.10.2022; MDPI
• Subjects: 1-Phosphatidylinositol 3-kinase; AKT protein; Antibodies; Breast cancer; Cancer therapies; Cell survival; Cell viability; Drug development; Enzyme inhibitors; Epidermal growth factor; Epidermal growth factor receptors; Gefitinib; Gene expression; IKK protein; IL-1β; Interleukin 6; Kinases; Laboratories; Lung cancer; Malignancy; Monocyte chemoattractant protein 1; Next-generation sequencing; NF-κB protein; Phosphorylation; Protein kinase inhibitors; Proteins; Stat3 protein; Therapeutic targets; TOR protein; Tumor suppressor genes; Tumors; South Korea; United States > US
• ISSN: 2072-6694; 2072-6694
• DOI: 10.3390/cancers14215215

Triple-negative breast cancer (TNBC) remains as an intractable malignancy with limited therapeutic targets. High expression of epidermal growth factor receptor (EGFR) has been associated with a poor prognosis of TNBC; however, EGFR targeting has failed with unfavorable clinical outcomes. Here, we performed a combinatorial screening of fifty-five protein kinase inhibitors with the EGFR inhibitor gefitinib in the TNBC cell line MDA-MB-231 and identified the IκB kinase (IKK) inhibitor IKK16 as a sensitizer of gefitinib. Cell viability and clonogenic survival assays were performed to evaluate the antiproliferative effects of the gefitinib and IKK16 (Gefitinib + IKK16) combination in TNBC cell lines. Western blot analyses were also performed to reveal the potential mode of action of this combination. In addition, next-generation sequencing (NGS) analysis was performed in Gefitinib+IKK16-treated cells. The Gefitinib+IKK16 treatment synergistically reduced cell viability and colony formation of TNBC cell lines such as HS578T, MDA-MB-231, and MDA-MB-468. This combination downregulated p-STAT3, p-AKT, p-mTOR, p-GSK3β, and p-RPS6. In addition, p-NF-κB and the total NF-κB were also regulated by this combination. Furthermore, NGS analysis revealed that NF-κB/RELA targets including CCL2, CXCL8, EDN1, IL-1β, IL-6, and SERPINE1 were further reduced and several potential tumor suppressors, such as FABP3, FADS2, FDFT1, SEMA6A, and PCK2, were synergistically induced by the Gefitinib-+IKK16 treatment. Taken together, we identified the IKK/NF-κB pathway as a potential target in combination of EGFR inhibition for treating TNBC.