Sublethal concentrations of Doxorubicin enhance osteosarcoma cell migration in an MMP-2-dependent manner
Previous research by Mohammed et al. (2021) revealed that sublethal concentrations of doxorubicin enhances cell migration in several cancer cell lines, including U2OS (23). To determine the concentrations of doxorubicin causing a sublethal effect on our U2OS cell line, a LDH release assay was performed. The highest sublethal concentration of doxorubicin on U2OS was 0.4 µM for both 24- and 48-hour treatments (Figure 2a). This doxorubicin sublethal concentration enhanced cell migration in WT cells using wound closure assays; albeit statistically non-significant, with nearly complete wound closure (approximately more than 80% closure) observed at 24 hours, compared to approximately 60% wound closure in the untreated sample (Figure 2b), supporting a previous study (23). Despite these results in the WT, the sublethal concentration of doxorubicin failed to enhance cell migration in MMP-2 KO cells, which continued to show minimal migration at 24 and 48 hours without or with 0.4 µM doxorubicin treatment (25% vs. 20%, respectively) (Figure 2c).
Our findings indicate that sublethal concentrations of doxorubicin augment cell migration in WT U2OS cells. However, this increase in cell migration is negated when the MMP-2 gene is knocked out. This impairment in cell migration in MMP-2 KO cells provides further evidence of the MMP-2 gene’s involvement in cancer cell migratory pathways.