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.