Related Experiment Video
Updated: Apr 30, 2026
Ex vivo Expansion of Tumor-reactive T Cells by Means of Bryostatin 1/Ionomycin and the Common Gamma Chain Cytokines Formulation
Published on: January 14, 2011
YB-1 inhibition suppresses osteosarcoma growth and reverses tumor immunosuppression
Sanjay V Malhotra1, Kirsten Stefan1, Jee Min Lee1
1Oregon Health & Science University Portland, OR United States.
Abstract:
Osteosarcoma (OS), the most common primary bone malignancy in adolescents and young adults, is still marked by poor long-term survival and poor mortality. Although immune checkpoint blockade (ICB) has transformed treatment for several cancers, its benefit in OS has been minimal, largely due to OS's "immune-cold" phenotype characterized by scarce tumor-infiltrating lymphocytes. Novel strategies are urgently needed to overcome this resistance. Y-box binding protein 1 (YB-1), a pro-oncogenic member of the cold-shock protein superfamily, represents a promising target to sensitize OS to ICB. Here, we evaluate SU056, a small-molecule YB-1 inhibitor, which both suppressed intrinsic OS tumor growth and remodeled the tumor microenvironment (TME). SU056 treatment markedly reduced immunosuppressive populations, including regulatory T cells (Tregs) and M2-polarized tumor-associated macrophages (TAMs), while enhancing infiltration of granzyme B-positive cytotoxic CD8⁺ T cell and NK cells. Combination therapy with SU056 and anti-PD-1 blockade produced superior tumor growth inhibition and significantly prolonged survival compared with either monotherapy. These findings highlight SU056 as a potent immunomodulatory agent and support its coadministration with ICB as a promising therapeutic approach for OS.
Insights
A novel Y-box binding protein 1 (YB-1) inhibitor, SU056, effectively combats osteosarcoma (OS) by reprogramming the tumor microenvironment. Combining SU056 with immune checkpoint blockade (ICB) shows promise for improving patient survival in OS treatment.
Area of Science:
- Oncology
- Immunology
- Molecular Biology
Background:
- Osteosarcoma (OS) is a primary bone cancer with poor survival rates, especially in young adults.
- Current immune checkpoint blockade (ICB) therapies are minimally effective in OS due to its "immune-cold" tumor microenvironment (TME) and lack of tumor-infiltrating lymphocytes.
- Y-box binding protein 1 (YB-1) is a pro-oncogenic target that may overcome resistance to ICB in OS.
Purpose of the Study:
- To evaluate the efficacy of SU056, a small-molecule YB-1 inhibitor, in suppressing osteosarcoma growth and sensitizing it to ICB.
- To investigate the immunomodulatory effects of SU056 on the tumor microenvironment (TME) in osteosarcoma.
- To assess the combined therapeutic potential of SU056 and anti-PD-1 blockade in osteosarcoma models.
Main Methods:
- Treatment of osteosarcoma models with SU056, a YB-1 inhibitor.
- Analysis of tumor growth inhibition and survival rates.
- Assessment of immune cell infiltration and polarization within the tumor microenvironment (TME) using flow cytometry and immunohistochemistry.
- Evaluation of combination therapy using SU056 and anti-PD-1 blockade.
Main Results:
- SU056 suppressed intrinsic osteosarcoma tumor growth and remodeled the TME.
- SU056 treatment reduced immunosuppressive cells like regulatory T cells (Tregs) and M2-polarized tumor-associated macrophages (TAMs).
- SU056 enhanced the infiltration of cytotoxic CD8+ T cells and NK cells, increasing anti-tumor immunity.
- Combination therapy with SU056 and anti-PD-1 blockade demonstrated superior tumor growth inhibition and significantly prolonged survival compared to monotherapy.
Conclusions:
- SU056 is a potent YB-1 inhibitor that effectively suppresses osteosarcoma growth.
- SU056 acts as an immunomodulatory agent, overcoming the "immune-cold" phenotype of osteosarcoma.
- Combining SU056 with ICB (anti-PD-1) represents a promising therapeutic strategy for improving osteosarcoma treatment outcomes.
Related Concept Videos
02:57Targeted Cancer Therapies
There are several types of targeted therapies against...
01:27Tumor Immunotherapy
01:15Receptor Downregulation in MVBs
The EGFR can initiate signaling pathways that lead to cell proliferation, migration, and differentiation. Overexpression of EGFR stimulates cells to proliferate. Excessive EGFR...