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CB65 and novel CB65 liposomal system suppress MG63 and Saos-2 osteosarcoma cell growth in vitro
Başak Işıl Zorba1, Özge Boyacıoğlu1,2, Tuğba Çağlayan1
1Graduate School of Science and Engineering, Department of Bioengineering, Hacettepe University, Ankara, Turkey.
Abstract:
Curable approaches for primary osteosarcoma are inadequate and urge investigation of novel therapeutic formulations. Cannabinoid ligands exert antiproliferative and apoptotic effect on osteosarcoma cells via cannabinoid 2 (CB2) or transient receptor potential vanilloid type (TRPV1) receptors. In this study, we confirmed CB2 receptor expression in MG63 and Saos-2 osteosarcoma cells by qRT-PCR and flow cytometry (FCM), then reported the reduction effect of synthetic specific CB2 receptor agonist CB65 on the proliferation of osteosarcoma cells by WST-1 (water-soluble tetrazolium-1) and RTCA (real-time impedance-based proliferation). CB65 revealed an IC50 (inhibitory concentration) for MG63 and Saos-2 cells as 1.11 × 10-11 and 4.95 × 10-11 M, respectively. The specific antiproliferative effect of CB65 on osteosarcoma cells was inhibited by CB2 antagonist AM630. CB65 induced late apoptosis of MG63 and Saos-2 cells at 24 and 48 h, respectively by FCM when applied submaximal concentration. A novel CB65 liposomal system was generated by a thin film hydration method with optimal particle size (141.7 ± 0.6 nm), polydispersity index (0.451 ± 0.026), and zeta potential (-10.9 ± 0.3 mV) values. The encapsulation efficiency (EE%) of the CB65-loaded liposomal formulation was 51.12%. The CB65 and CB65-loaded liposomal formulation releasing IC50 of CB65 reduced proliferation by RTCA and invasion by scratch assay and induced late apoptosis of MG63 and Saos-2 cells, by FCM. Our results demonstrate the CB2 receptor-mediated antiproliferative and apoptotic effect of a new liposomal CB65 delivery system on osteosarcoma cells that can be used as a targeted and intelligent tool for bone tumors to ameliorate pediatric bone cancers following in vivo validation.
Insights
Novel liposomal CB65 effectively reduces osteosarcoma cell proliferation and induces apoptosis via CB2 receptors. This targeted delivery system shows promise for treating bone cancers, pending in vivo validation.
Area of Science:
- Oncology
- Pharmacology
- Nanotechnology
Background:
- Primary osteosarcoma treatment remains challenging, necessitating novel therapeutic strategies.
- Cannabinoid ligands, specifically targeting cannabinoid 2 (CB2) or transient receptor potential vanilloid type 1 (TRPV1) receptors, exhibit antiproliferative and apoptotic effects on osteosarcoma cells.
Purpose of the Study:
- To investigate the antiproliferative and apoptotic effects of a synthetic CB2 receptor agonist, CB65, on osteosarcoma cells.
- To develop and evaluate a novel liposomal delivery system for CB65 to enhance its efficacy in treating osteosarcoma.
Main Methods:
- Confirmed CB2 receptor expression in MG63 and Saos-2 osteosarcoma cells using qRT-PCR and flow cytometry (FCM).
- Assessed the antiproliferative effects of CB65 using WST-1 and real-time cell analysis (RTCA).
- Developed and characterized a CB65-loaded liposomal formulation, evaluating particle size, polydispersity index, zeta potential, and encapsulation efficiency.
Main Results:
- CB65 demonstrated significant antiproliferative effects on MG63 and Saos-2 cells, with IC50 values in the nanomolar range.
- The antiproliferative action of CB65 was confirmed to be CB2 receptor-mediated, as it was inhibited by the CB2 antagonist AM630.
- CB65 induced late apoptosis in osteosarcoma cells and the liposomal formulation reduced proliferation and invasion, while also inducing apoptosis.
Conclusions:
- The study successfully developed a novel liposomal CB65 delivery system with favorable physicochemical properties.
- This liposomal formulation exhibits CB2 receptor-mediated antiproliferative and apoptotic effects on osteosarcoma cells.
- The CB65 liposomal system represents a promising targeted therapeutic tool for bone tumors, warranting further in vivo investigation for pediatric bone cancer treatment.
