Cytotoxic and apoptotic effects of zoledronic acid on D-17 canine osteosarcoma cell line

Pets are exposed to a multitude of carcinogenic substances in the modern world. Consequently, high rates of cancer are observed, particularly in middle-aged cats and dogs. Although bisphosphonates have been incorporated into the treatment of human cancers, there are few animal-specific studies. As the number of cancer cases in animals continues to rise, it becomes increasingly important to evaluate anticancer drugs on a species-specific basis.

The present study aimed to examine the impact of zoledronic acid (ZA) on apoptotic pathways in canine osteosarcoma (OSA) cell lines.

The apoptotic effects of ZA administration on D-17 canine OSA cells were analysed by determining apoptotic DNA breaks, caspase-3, -8 and -9 levels by ELISA method and Bax/Bcl-2 ratio by qRT-PCR. The effect of ZA on the colony formation capacity of cells was evaluated by crystal violet staining method. The mineral binding capacity of ZA application in cells was investigated by Alizarin Red S staining technique. The change in alkaline phosphatase enzyme activity in OSA cells due to ZA treatment was determined using the colorimetric method. The antimetastatic effect was determined using the wound healing method, which evaluated the migration potential of cells.

While ZA application did not show a significant cytotoxic effect in the cells in the first 24 h, a decrease observed in the viability of the cells depending on the increasing dose and time. Low dose ZA (1, 5, 7.5, 10 µM) concentrations increased mineral content and alkaline phosphatase enzyme activity. A significant decrease was found in the expression levels of survivin, which determines the cell survival, depending on the dose and time.

It is expected that our obtained data will contribute to the more effective treatment of the disease by creating different treatment options for clinicians in the light of increasing knowledge in cancer cell biology.