Research Paper Volume 13, Issue 17 pp 21090—21101

Effect of the Notch1-mediated PI3K-Akt-mTOR pathway in human osteosarcoma

Kexiang Zhang1, , Song Wu1, , Hongwei Wu2, , Li Liu1, , Jiahui Zhou1, ,

  • 1 Department of Orthopedics, Third Xiangya Hospital, Central South University, Changsha 410013, Hunan Province, China
  • 2 Department of Orthopedics, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha 410013, Hunan Province, China

Received: February 20, 2020       Accepted: November 10, 2020       Published: September 8, 2021
How to Cite

Copyright: © 2021 Zhang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Purpose: Osteosarcoma is one of the most common malignant bone tumours in early adolescence. The incidence rate of osteosarcoma has stagnated over the past 30 years, highlighting the need to develop novel therapies. In osteosarcoma cells, Notch1 expression is absent, and the Notch1 pathway is related to cancer cell proliferation, apoptosis and autophagy. Our study aimed to investigate the role of Notch1 in osteosarcoma development.

Methods: We measured NICD1 expression induced by doxycycline treatment at various concentrations. The viability of human osteosarcoma cells (MG-63) induced by doxycycline was measured. Flow cytometry and cell apoptosis analysis were conducted to measure the effect of Notch1 on the cell cycle of human osteosarcoma cells. We also used a GFP-LC3 plasmid to detect Notch1-induced autophagy in MG-63 cells. Western blotting was conducted to analyse expression of the PI3K/Akt/mTOR signalling pathway through Notch1 induction by doxycycline.

Results: In this study, we demonstrated that Notch1 activation by doxycycline potently suppressed cell proliferation by inducing S phase arrest in osteosarcoma cells. Doxycycline-induced Notch1 activation also induced apoptosis and autophagy in osteosarcoma cells. Moreover, we found that Notch1 inhibited PI3K/Akt/mTOR signalling to induce apoptosis and autophagy.

Conclusion: In summary, our results revealed that Notch1 activation by doxycycline induces S phase arrest, apoptosis and autophagy by blocking PI3K/Akt/mTOR signalling in human osteosarcoma cells. Notch1 may be a potential clinical antitumour target for osteosarcoma therapy.


OS: Osteosarcoma; LC3: light chain 3; Notch1-4: Notch designates a family; mTOR: mammalian target of rapamycin complex; MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-di-phenyltetrazolium bromide; DOX: doxycycline; PI: propidium iodide; MMPs: metalloproteinases.