Related Experiment Video
Updated: Mar 12, 2026
Enrichment for Chemoresistant Ovarian Cancer Stem Cells from Human Cell Lines
Published on: September 10, 2014
Treatment of a chemoresistant neuroblastoma cell line with the antimalarial ozonide OZ513
Don W Coulter1, Timothy R McGuire2, John G Sharp3
1College of Medicine, Division of Pediatrics, University of Nebraska Medical Center, Omaha, NE, USA.
Background:
Evaluate the anti-tumor activity of ozonide antimalarials using a chemoresistant neuroblastoma cell line, BE (2)-c.
Methods:
The activity of 12 ozonides, artemisinin, and two semisynthetic artemisinins were tested for activity against two neuroblastoma cell-lines (BE (2)-c and IMR-32) and the Ewing's Sarcoma cell line A673 in an MTT viability assay. Time course data indicated that peak effect was seen 18 h after the start of treatment thus 18 h pre-treatment was used for all subsequent experiments. The most active ozonide (OZ513) was assessed in a propidium iodide cell cycle flow cytometry analysis which measured cell cycle transit and apoptosis. Metabolic effects of OZ513 in BE (2)-c cells was evaluated. Western blots for the apoptotic proteins cleaved capase-3 and cleaved PARP, the highly amplified oncogene MYCN, and the cell cycle regulator CyclinD1, were performed. These in-vitro experiments were followed by an in-vivo experiment in which NOD-scid gamma immunodeficient mice were injected subcutaneously with 1 × 106 BE (2)-c cells followed by immediate treatment with 50-100 mg/kg/day doses of OZ513 administered IP three times per week out to 23 days after injection of tumor. Incidence of tumor development, time to tumor development, and rate of tumor growth were assessed in DMSO treated controls (N = 6), and OZ513 treated mice (N = 5).
Results:
It was confirmed that five commonly used chemotherapy drugs had no cytotoxic activity in BE (2)-c cells. Six of 12 ozonides tested were active in-vitro at concentrations achievable in vivo with OZ513 being most active (IC50 = 0.5 mcg/ml). OZ513 activity was confirmed in IMR-32 and A673 cells. The Ao peak on cell-cycle analysis was increased after treatment with OZ513 in a concentration dependent fashion which when coupled with results from western blot analysis which showed an increase in cleaved capase-3 and cleaved PARP supported an increase in apoptosis. There was a concentration dependent decline in the MYCN and a cyclinD1 protein indicative of anti-proliferative activity and cell cycle disruption. OXPHOS metabolism was unaffected by OZ513 treatment while glycolysis was increased. There was a significant delay in time to tumor development in mice treated with OZ513 and a decline in the rate of tumor growth.
Conclusions:
The antimalarial ozonide OZ513 has effective in-vitro and in-vivo activity against a pleiotropic drug resistant neuroblastoma cell-line. Treatment with OZ513 increased apoptotic markers and glycolysis with a decline in the MYCN oncogene and the cell cycle regulator cyclinD1. These effects suggest adaptation to cellular stress by mechanism which remain unclear.
Insights
The antimalarial ozonide OZ513 demonstrates significant anti-tumor activity against chemoresistant neuroblastoma cells. This compound effectively reduced tumor growth in vivo by increasing apoptosis and disrupting cell cycle progression.
Area of Science:
- Pharmacology
- Oncology
- Drug Discovery
Background:
- Neuroblastoma is a challenging pediatric cancer, often exhibiting resistance to conventional chemotherapy.
- Ozonide antimalarials, derived from artemisinin, are being explored for novel anti-cancer properties.
Purpose of the Study:
- To evaluate the anti-tumor efficacy of ozonide antimalarials against a drug-resistant neuroblastoma cell line (BE (2)-c).
- To investigate the mechanisms underlying the anti-cancer effects of the most potent ozonide, OZ513.
Main Methods:
- In vitro screening of 12 ozonides, artemisinin, and derivatives against neuroblastoma and Ewing's Sarcoma cell lines.
- Flow cytometry and Western blot analyses to assess apoptosis, cell cycle, and protein expression (MYCN, CyclinD1).
- In vivo studies using immunodeficient mice xenografted with neuroblastoma cells, treated with OZ513.
Main Results:
- OZ513 exhibited potent in vitro activity (IC50 = 0.5 mcg/ml) against multiple neuroblastoma and Ewing's Sarcoma cell lines, surpassing conventional chemotherapy.
- OZ513 induced apoptosis, disrupted cell cycle progression, and decreased MYCN and CyclinD1 protein levels.
- In vivo, OZ513 significantly delayed tumor development and reduced tumor growth rate in mice.
Conclusions:
- The antimalarial ozonide OZ513 shows promising in vitro and in vivo anti-tumor activity against pleiotropic drug-resistant neuroblastoma.
- OZ513's mechanism involves increased apoptosis and glycolysis, alongside reduced MYCN and CyclinD1, suggesting cellular stress adaptation.
- Further research is needed to elucidate the precise mechanisms of OZ513's anti-cancer effects.
Related Concept Videos
02:56Treatment Resistant Cancers
02:49Cancer Therapies
However, cancer treatments can pose several challenges, as therapies used to kill cancer cells are generally also toxic to normal cells. Moreover, cancer cells mutate rapidly and can develop resistance to chemical agents or radiation therapy. Besides, all types of cancer cells may not respond to the same therapy. Some cancer cells respond to one...