Effect of Iron Superoxide and Nickel Oxide Nanoparticles Alone and Combined with Coenzyme Q10 on hsa_circ_0001518 Expression in Breast Tumor-bearing BALB/c Mice

Breast cancer is considered the second prevailed type of cancer among women. Circular RNAs are a group of non-coding RNAs that play a significant role in tumorigenesis and the progression of malignancies. This study aimed to determine the inhibitory concentration (IC50) of iron superoxide (Fe2O3) and nickel oxide (NiO) nanoparticles and coenzyme Q10 (Q10) antioxidant against 4T1 cell line and their single and combination treatment effect on hsa_circ_0001518 expression in healthy and breast tumor mice.

The 4T1 cell line was cultivated and treated with Fe2O3 (50, 100, 150, and 200 μg/mL) and NiO (10, 20, 30, and 40 μg/mL) nanoparticles, and Q10 antioxidant (20, 60, 80, and 100 μg/mL) for 48 hours. Cell viability was measured using the MTT assay. The expression of hsa_circ_0001518 after treatment with the half-maximal inhibitory concentration (IC50) of all single and combined antioxidant and NPs in healthy and breast tumor-bearing mice were evaluated by qRT-PCR.

The IC50 of Fe2O3 and NiO nanoparticles and Q10 antioxidant after 48h was 92.42 μg/mL, 21.49 μg/mL, and 83.47 μg/mL, respectively. The qRT-PCR results showed that combined treatment with antioxidant and NPs caused a more significant downregulation in the expression of has_circ1518 in breast tumor-bearing mice than either agent alone. In addition, combined treatment with antioxidant and NPs caused a more significant downregulation in the expression of has_circ1518 in breast tumor-bearing mice than either agent alone.

This study suggests that the combined treatment of Fe2O3 and NiO nanoparticles with Q10 could be exploited as a potential source for developing novel drugs against breast cancer.