Time-dependent effects of TKIs on sarcoma cell viability and CSC enrichment
. A673, SK-LMS, and SW982 cells were exposed to low- and high-dose sorafenib for 1 – 3 days. SSChi cells were then analyzed by flow cytometry using 7AAD, and ALDH expression was assessed using ALDEFLUOR™. A. A673 cell viability was unaffected over 3 days of culture at 4 μM sorafenib, while 32 μM sorafenib demonstrated significant reduction in cell viability over time. B. At 4 μM sorafenib, SK-LMS cell viability overall paralleled that of controls except for a transient decrease on day 2. In contrast, at 32 μM sorafenib, there was ongoing significant reduction in cell viability over time, although cells were less sensitive to sorafenib than A673 cells. C. At 4 μM sorafenib, A673 cells showed progressive significant enrichment in ALDHbright sub-populations during 3 days of culture. In contrast, at 32 μM sorafenib, there is significant reduction in ALDHbright sub-populations on days 2 and 3. D. At 4 and 32 μM sorafenib, SK-LMS ALDHbright sub-populations were elevated after 1 day of sorafenib culture and continued to show enrichment in ALDHbright cells on days 2 and 3. E. SK-LMS cell viability was unaffected over 3 days of culture at 32 μM pazopanib, while sorafenib and regorafenib demonstrated similar anti-viability effects. For each panel, a representative experiment of 3 replicates is shown. *P < 0.05, **P < 0.01, and ***P < 0.001 via one-way ANOVA with Tukey’s post-test.