Figure 3. FXYD2 modulates Na⁺/K⁺-ATPase activity in OCCC cells.

A. Na⁺/K⁺-ATPase activity was assessed in ovarian cancer cell lines. Cells that were first blocked in K⁺-free buffer were then reactivated in Na⁺-free, 4 mM K⁺ solution. Na⁺/K⁺-ATPase was measured using a fluorescent indicator, SBFI. The F340/F380 changes (ΔF340/F380) following Na⁺ effluence in ovarian cancer cells were shown in the histogram. B. Na⁺/K⁺-ATPase activity was decreased in FXYD2-knockdown cells. C. and D. digoxin dose-dependently inhibited the Na⁺/K⁺-ATPase activity in OCCC but not in non-OCCC cells. Data are presented as the mean ± SD from 50 individual cells. All experimental groups were analyzed using an unpaired t test.