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Published on: March 30, 2019
Effects of siRNA-mediated HIF-1α gene silencing on angiogenesis in osteosarcoma
Xu-Dong Zhang1, Qiang Wu2, Shu-Hua Yang3
1Dr. Xu-dong Zhang, Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Objective:
To explore angiogenesis in osteosarcoma under the condition of hypoxia-inducible factor (HIF)-1α gene silenced by small interference RNA (siRNA).
Methods:
The SaOS-2 osteosarcoma cells, transfected with the recombinant plasmid pSilencer2.1-HIF-1α or pSilencer2.1-SCR, were classified as HIF-1α/siRNA group or SCR/siRNA group, respectively. In which, vascular endothelial growth factor (VEGF) immunohistochemistry were performed. HIF-1α and VEGF protein contents were detected by western blot. Gene expressions of HIF-1α and VEGF were quantified by qPCR. Then the transfected SaOS-2 cells were inoculated in nude mice and transplantation tumor were checked via HE staining, VEGF and CD34 immunohistochemistry, and calculation of microvascular density (MVD).
Results:
In vitro, VEGF immunohistochemistry stains, HIF-1α and VEGF protein contents, and the relative expressions of HIF-1α mRNA and VEGF mRNA in HIF-1α/siRNA group were obviously reduced. In vivo, morphological observation illustrated that heteromorphism were not obvious in the cells of HIF-1α/siRNA group and vascular systems were sparse in its transplantation tumor tissue, and immunohistochemistry revealed that both VEGF and CD34 stains were significantly decreased in HIF-1α/siRNA group, and MVD in HIF-1α/siRNA group (7.3±1.1) were obviously less than that in SCR/siRNA group (17.2±3.2) (P<0.05).
Conclusion:
Angiogenesis in osteosarcoma can be inhibited by siRNA-mediated HIF-1α gene silencing, which is expected to provide a novel and attractive target of therapeutic strategies of osteosarcoma.
Insights
Small interference RNA (siRNA) silencing of the hypoxia-inducible factor (HIF)-1α gene effectively inhibits angiogenesis in osteosarcoma. This targeted approach offers a promising new therapeutic strategy for osteosarcoma treatment.
Area of Science:
- Oncology
- Molecular Biology
- Biomedical Research
Background:
- Osteosarcoma angiogenesis is crucial for tumor growth and metastasis.
- Hypoxia-inducible factor (HIF)-1α is a key regulator of angiogenesis.
- Targeting HIF-1α presents a potential therapeutic strategy for osteosarcoma.
Purpose of the Study:
- To investigate the effect of HIF-1α gene silencing using small interference RNA (siRNA) on angiogenesis in osteosarcoma.
- To evaluate the impact of HIF-1α inhibition on vascular endothelial growth factor (VEGF) expression and microvascular density (MVD) in osteosarcoma models.
Main Methods:
- SaOS-2 osteosarcoma cells were transfected with HIF-1α-targeting siRNA or a scrambled control (SCR) siRNA.
- In vitro: VEGF and HIF-1α protein and mRNA levels were assessed using Western blot and qPCR.
- In vivo: Tumorigenicity and angiogenesis were evaluated in nude mice xenografts via HE staining, immunohistochemistry (VEGF, CD34), and MVD quantification.
Main Results:
- siRNA-mediated HIF-1α gene silencing significantly reduced VEGF expression in osteosarcoma cells.
- In vivo studies showed decreased vascularization and significantly lower MVD in tumors with silenced HIF-1α.
- Tumor tissues from the HIF-1α/siRNA group exhibited sparse vascular systems and reduced VEGF and CD34 staining.
Conclusions:
- siRNA-mediated silencing of HIF-1α effectively inhibits angiogenesis in osteosarcoma.
- Targeting HIF-1α represents a novel and promising therapeutic strategy for osteosarcoma.
- This study provides a foundation for developing new anti-angiogenic therapies for osteosarcoma.
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