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Inhibitory Effects of a Reengineered Anthrax Toxin on Canine and Human Osteosarcoma Cells
Jonathan Mackowiak da Fonseca1, Ivone Izabel Mackowiak da Fonseca1, Marcia Kazumi Nagamine1
1Department of Pathology, School of Veterinary Medicine and Animal Science, University of Sao Paulo, Sao Paulo 05508-270, SP, Brazil.
Abstract:
Canine and human osteosarcomas (OSA) share similarities. Novel therapies are necessary for these tumours. The Bacillus anthracis toxin was reengineered to target and kill cells with high expressions of matrix metalloproteinases (MMPs) and urokinase plasminogen activator (uPA). Since canine OSA express MMPs and uPA, we assessed whether the reengineered toxin could show efficacy against these tumours. Two OSA cell lines (canine D17 and human MG63) and a non-neoplastic canine osteoblastic cell line (COBS) were used. Cells were treated with different concentrations of the reengineered anthrax toxin and cell viability was quantified using MTT assay. The cell cycle, apoptosis, and necrosis were analysed by flow cytometry. The wound-healing assay was performed to quantify the migration capacity of treated cells. D17 and MG63 cells had significantly decreased viability after 24 h of treatment. Cell cycle analysis revealed that OSA cells underwent apoptosis when treated with the toxin, whereas COBS cells arrested in the G1 phase. The wound-healing assay showed that D17 and MG63 cells had a significantly reduced migration capacity after treatment. These results point for the first time towards the in vitro inhibitory effects of the reengineered anthrax toxin on OSA cells; this reengineered toxin could be further tested as a new therapy for OSA.
Insights
A reengineered Bacillus anthracis toxin effectively reduced viability and migration in canine and human osteosarcoma cells. This novel toxin shows promise as a potential new therapy for osteosarcoma (OSA).
Area of Science:
- Oncology
- Biochemistry
- Veterinary Medicine
Background:
- Canine and human osteosarcomas (OSA) exhibit similar characteristics, necessitating novel therapeutic strategies.
- Matrix metalloproteinases (MMPs) and urokinase plasminogen activator (uPA) are highly expressed in OSA and present potential therapeutic targets.
Purpose of the Study:
- To evaluate the efficacy of a reengineered Bacillus anthracis toxin targeting MMPs and uPA against canine and human osteosarcoma (OSA) cells in vitro.
- To assess the toxin's impact on OSA cell viability, cell cycle, apoptosis, necrosis, and migration.
Main Methods:
- Utilized canine osteosarcoma (D17) and human osteosarcoma (MG63) cell lines, alongside a non-neoplastic canine osteoblastic cell line (COBS).
- Treated cells with varying concentrations of the reengineered anthrax toxin.
- Quantified cell viability using MTT assay, analyzed cell cycle, apoptosis, and necrosis via flow cytometry, and assessed cell migration using a wound-healing assay.
Main Results:
- Significant decrease in viability observed in D17 and MG63 cells after 24-hour toxin treatment.
- Osteosarcoma cells exhibited apoptosis upon treatment, while non-neoplastic COBS cells showed G1 phase arrest.
- Toxin treatment significantly reduced the migration capacity of D17 and MG63 cells.
Conclusions:
- The reengineered anthrax toxin demonstrates in vitro inhibitory effects on osteosarcoma (OSA) cells.
- This study presents the first evidence of the reengineered toxin's efficacy against OSA, suggesting its potential as a novel therapeutic agent for further investigation.
