Inhibition of programmed death ligand 1 (PD-L1) expression in breast cancer cells by sesamin

• Main Authors: Prachya Kongtawelert, Benjawan Wudtiwai, Thuzar Hla Shwe, Peraphan Pothacharoen, Thanyaluck Phitak
• Format: Journal
• Published: 2020
• Subjects: Immunology and Microbiology; Medicine; Pharmacology, Toxicology and Pharmaceutics
• Online Access: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85087655505&origin=inward; http://cmuir.cmu.ac.th/jspui/handle/6653943832/70646
• Institution: Chiang Mai University

© 2020 Elsevier B.V. Programmed death ligand 1 (PD-L1) is overexpressed in some metastatic breast cancer subtypes, specifically triple-negative breast cancer (TNBC). This feature can assist in the eradication of anti-tumor immunity, thereby enhancing the survival of the tumor. This study aims to explore how sesamin affects PD-L1 expression in breast cancer cells and its related molecular mechanisms. We found high levels of expression of PD-L1 in both mRNA and protein levels in the TNBC cell line, MDA-MB231, but not in the luminal type-breast cancer cell line, MCF-7. We then demonstrated the tumor suppressive effect of sesamin, which induced the inhibition of cell proliferation in MDA-MB231 cells. Additionally, sesamin triggered PD-L1 downregulation (both mRNA and protein) through the inhibition of AKT, NF-κB and JAK/Stat signaling in MDA-MB231 cells. Moreover, the migration ability of MDA-MB231 cells was effectively diminished by sesamin via inhibition of the activation of MMP-9 and MMP-2. In summary, this study demonstrated that sesamin suppresses MDA-MB231 breast cancer cells’ proliferation and migration; and decreases the expression of PD-L1 via the downregulation of AKT, NF-κB, and JAK/Stat signaling. Therefore, sesamin may be an effective alternative and novel therapeutic option for immunotherapy in breast cancer cells with high PD-L1 expression.