Acid-Sensitive Outwardly Rectifying Cl- Current in OV2944 Mouse Ovarian Cancer Cells

Abstract

Background/Aims: Extracellular acidic conditions impair cellular activities; however, some cancer cells drive cellular signaling to adapt to the acidic environment. It remains unclear how ovarian cancer cells sense changes in extracellular pH. This study was aimed at characterizing acid-inducible currents in an ovarian cancer cell line and evaluating the involvement of these currents in cell viability. Methods: The biophysical and pharmacological properties of membrane currents in OV2944, a mouse ovarian cancer cell line, were studied using the whole-cell configuration of the patch-clamp technique. Viability of this cell type in acidic medium was evaluated using the MTT assay. Results: OV2944 had significant acid-sensitive outwardly rectifying (ASOR) Cl− currents at a pH50 of 5.3. The ASOR current was blocked by pregnenolone sulfate (PS), a steroid ion channel modulator that blocks the ASOR channel as one of its targets. The viability of the cells was reduced after exposure to an acidic medium (pH 5.3) but was slightly restored upon PS administration. Conclusion: These results offer first evidence for the presence of ASOR Cl− channel in ovarian cancer cells and indicate its involvement in cell viability under acidic environment.