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Updated: Apr 11, 2026
Intratibial Osteosarcoma Cell Injection to Generate Orthotopic Osteosarcoma and Lung Metastasis Mouse Models
Published on: October 28, 2021
Rapamycin inhibits tumor growth of human osteosarcomas
Shichang Zhao1, Nanji Lu, Yimin Chai
1Department of Orthopedic Surgery, Shanghai Jiaotong University Affiliated Sixth People's Hospital, No. 600 Yishan Road, Shanghai 200233, China.
Purpose:
Treatment options for osteosarcoma are limited due to its resistance to chemotherapy and radiotherapy. Signaling through the mammalian target of rapamycin (mTOR) pathway contributes to cell proliferation and chemoresistance of many cancers. Rapamycin, as an inhibitor of mTOR, has been developed as potentially valuable therapeutic agent. In this report, we evaluated the effects of rapamycin on human osteosarcoma cells' growth in vitro and in vivo.
Methods:
Proliferation of osteosarcoma cells treated with rapamycin at different time periods was detected and changes in the cell cycle were measured by MTS and flow cytometry, respectively. Autophagy induced by rapamycin in osteosarcoma cells and the expression of cell cycle regulating proteins were detected by Western blotting. The effect of rapamycin on tumor growth in vivo was detected using mice xenograph models.
Results:
The proliferation of osteosarcoma cells was signif- icantly inhibited by rapamycin treatment in a concentration-dependent manner and the cell cycle progression was impaired with G1 arrest. Rapamycin induced autophagy, increased the expression of p27 and decreased the expression of Cyclin D1. In addition, rapamycin suppressed the tumor growth in mice xenograph models.
Conclusions:
The potent antiproliferative activities of mTOR inhibitor rapamycin has been proven. Theses results strongly indicate that rapamycin may be a promising agent against osteosarcomas.
Insights
Rapamycin, an mTOR inhibitor, effectively inhibited osteosarcoma cell growth and tumor development in mice. This study demonstrates rapamycin
Area of Science:
- Oncology
- Molecular Biology
- Pharmacology
Background:
- Osteosarcoma treatment options are limited due to chemoresistance and radioresistance.
- The mammalian target of rapamycin (mTOR) pathway promotes cancer cell proliferation and chemoresistance.
- Rapamycin is an mTOR inhibitor with potential therapeutic value in cancer treatment.
Purpose of the Study:
- To evaluate the in vitro and in vivo effects of rapamycin on human osteosarcoma cells.
- To investigate rapamycin's impact on osteosarcoma cell proliferation, cell cycle, and autophagy.
Main Methods:
- Osteosarcoma cell proliferation was assessed using MTS assays.
- Cell cycle analysis was performed using flow cytometry.
- Autophagy and cell cycle protein expression (p27, Cyclin D1) were analyzed by Western blotting.
- In vivo efficacy was evaluated using mouse xenograft models.
Main Results:
- Rapamycin significantly inhibited osteosarcoma cell proliferation in a dose-dependent manner.
- Rapamycin treatment led to G1 cell cycle arrest and induced autophagy.
- Rapamycin increased p27 expression and decreased Cyclin D1 expression.
- Rapamycin suppressed tumor growth in vivo.
Conclusions:
- Rapamycin exhibits potent antiproliferative activity against osteosarcoma.
- Rapamycin demonstrates significant anti-tumor effects in vitro and in vivo.
- Rapamycin is a promising therapeutic agent for osteosarcoma treatment.
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