Files
Document type
ArticleVersion
Published versionPublication date
Publication license
Please use this identifier to cite or link to this item: https://hdl.handle.net/2445/177224
Silencing of CD47 and SIRPα by Polypurine reverse Hoogsteen hairpins to promote MCF-7 breast cancer cells death by PMAdifferentiated THP-1 cells
Journal Title
Director/Tutor
Journal ISSN
Volume Title
Related resource
Abstract
Background: In the context of tumor immunology, tumor cells have been shown to overexpress CD47, an antiphagocytic signal directed to macrophages to escape from phagocytosis by interacting with Signal Regulatory Protein α SIRPα. In the present work, we designed Polypurine reverse Hoogsteen hairpins, PPRHs, to silence the expression of CD47 in tumor cells and SIRPα in macrophages with the aim to eliminate tumor cells by macrophages in co-culture experiments. Methods: THP-1 cells were differentiated to macrophages with PMA. The mRNA levels of differentiation markers CD14 and Mcl-1 mRNA and pro-inflammatory cytokines (IL-1β, IL-18, IL-6, IL-8 and TNF-α) were measured by qRTPCR. The ability of PPRHs to silence CD47 and SIRPα was evaluated at the mRNA level by qRT-PCR and at the protein level by Western Blot. Macrophages were co-cultured with tumor cells in the presence of PPRHs to silence CD47 and/or SIRPα. Cell viability was assessed by MTT assays. Results: THP-1 cells differentiated to macrophages with PMA showed an increase in macrophage surface markers (CD14, Mcl-1) and pro-inflammatory cytokines (IL-1β, IL-18, IL-6, IL-8 and TNF-α). PPRHs were able to decrease both CD47 expression in MCF-7 cell line and SIRPα expression in macrophages at the mRNA and protein levels. In the presence of PPRHs, MCF-7 cells were eliminated by macrophages in co-culture experiments, whereas they survived in the absence of PPRHs. Conclusions: Our data support the usage of PPRHs to diminish CD47/SIRPα interaction by decreasing the expression of both molecules thus resulting in an enhanced killing of MCF-7 cells by macrophages, which might translate into beneficial effects in cancer therapy. These results indicate that PPRHs could represent a new approach with immunotherapeutic applications. Keywords: Immunotherapy, PPRH, CD47, SIRPα, Macrophage
Subject (English)
Citation
Citation
BENER, Gizem, et al. Silencing of CD47 and SIRPα by Polypurine reverse Hoogsteen hairpins to promote MCF-7 breast cancer cells death by PMAdifferentiated THP-1 cells. BMC Immunology. 2016. Vol. 17. ISSN 1471-2172. [consulted: 8 of August of 2026]. Available at: https://hdl.handle.net/2445/177224