Figure 4.

Inhibition of (A) human A431 and (B) human SCC13 cell spheroids formation by secosteroids. Cells suspended in tumerosphere medium (DMEM, 0.4% BSA, 20 ng/ml EGF, 10 ng/ml FGF, 5 ug/ml insulin) were treated with the selected secosteroids and seeded into low adhesion 96 well plates (1,000 cells/well) then incubated for 7 days at 37°C. Spheroids ≥50 um in size were counted using Cytation 5 (BioTek Instruments, Inc.). Scale bar=200 µm. Data represent means ± SEM (n=6) with ^**P<0.01, ^***P<0.001, ^****P<0.0001 by the Student's t-test in A or ^####P<0.0001 at one-way AVOVA with Dunnett's multi comparison post-hoc test.