Related Experiment Video
Updated: Feb 17, 2026
A Mouse Model of Incompletely Resected Soft Tissue Sarcoma for Testing Neoadjuvant Therapies
Published on: July 28, 2020
Effects of chondroitin sulfate proteoglycan 4 (NG2/CSPG4) on soft-tissue sarcoma growth depend on tumor developmental
Shu-Hsuan Claire Hsu1, Puviindran Nadesan1, Vijitha Puviindran1
1From the Department of Orthopaedic Surgery and RegenerationNext Initiative and.
Abstract:
Sarcomas, and the mesenchymal precursor cells from which they arise, express chondroitin sulfate proteoglycan 4 (NG2/CSPG4). However, NG2/CSPG4's function and its capacity to serve as a therapeutic target in this tumor type are unknown. Here, we used cells from human tumors and a genetically engineered autochthonous mouse model of soft-tissue sarcomas (STSs) to determine NG2/CSPG4's role in STS initiation and growth. Inhibiting NG2/CSPG4 expression in established murine and human STSs decreased tumor volume by almost two-thirds and cell proliferation rate by 50%. NG2/CSPG4 antibody immunotherapy in human sarcomas established as xenografts in mice similarly decreased tumor volume, and expression of a lentivirus blocking NG2/CSPG4 expression inhibited tumor cell proliferation and increased the latency of engraftment. Gene profiling showed that Ng2/Cspg4 deletion altered the expression of genes regulating cell proliferation and apoptosis. Surprisingly, Ng2/Cspg4 deletion at the time of tumor initiation resulted in larger tumors. Gene expression profiling indicated substantial down-regulation of insulin-like growth factor binding protein (Igfbp) genes when Ng2/Cspg4 is depleted at tumor initiation, but not when Ng2/Cspg4 is depleted after tumor initiation. Such differences may have clinical significance, as therapeutic targeting of a signaling pathway such as NG2/CSPG4 may have different effects on cell behavior with tumor progression. NG2/CSPG4 depletion has divergent effects, depending on the developmental stage of sarcoma. In established tumors, IGF signaling is active, and NG2 inhibition targets cell proliferation and apoptosis.
Insights
Targeting chondroitin sulfate proteoglycan 4 (NG2/CSPG4) effectively reduces established soft-tissue sarcoma growth. However, NG2/CSPG4 depletion at tumor initiation paradoxically increases tumor size, highlighting stage-dependent therapeutic effects.
Area of Science:
- Oncology
- Cancer Biology
- Molecular Therapeutics
Background:
- Chondroitin sulfate proteoglycan 4 (NG2/CSPG4) is expressed in sarcomas and their precursor cells.
- The functional role and therapeutic potential of NG2/CSPG4 in sarcomas remain largely unknown.
Purpose of the Study:
- To investigate the role of NG2/CSPG4 in soft-tissue sarcoma (STS) initiation and progression.
- To evaluate NG2/CSPG4 as a potential therapeutic target in STS.
Main Methods:
- Utilized human STS cells and a genetically engineered autochthonous mouse model.
- Assessed the impact of NG2/CSPG4 inhibition via antibody immunotherapy and lentiviral gene silencing.
- Performed gene expression profiling to analyze molecular alterations.
Main Results:
- Inhibition of NG2/CSPG4 in established tumors significantly reduced tumor volume and proliferation.
- NG2/CSPG4 antibody immunotherapy and gene silencing decreased tumor growth in xenografts.
- Depletion of NG2/CSPG4 at tumor initiation led to increased tumor size, associated with altered insulin-like growth factor binding protein (IGFBP) gene expression.
Conclusions:
- NG2/CSPG4 plays a dual role in STS, with inhibitory effects on established tumors but promoting effects during initiation.
- Therapeutic targeting of NG2/CSPG4 may have stage-specific efficacy, impacting cell proliferation and apoptosis differently based on tumor progression.
- Understanding these divergent effects is crucial for developing effective clinical strategies against sarcomas.
