Characteristics of volume-sensitive chloride currents in side population cells of chronic myeloid leukemia
QI Shan-shan
LYU Liang
YANG Lin-jie
Abstract：Objective To investigate the characteristics of volume-sensitive chloride currents in side population(SP)cells of the chronic myeloid leukemia(CML)cell line K562 and compare them with non-side population(NSP)cells.Methods Based on the property of SP cells to efflux the fluorescent dye Hoechst 33342,individual SP and NSP cells in K562 cultures were identified under an inverted fluorescence microscope.Whole-cell patch-clamp recordings were used to measure volume-sensitive chloride currents in SP and NSP cells.Changes in extracellular osmolarity or ap-plication of chloride channel blockers were performed to assess their effects on these currents.Results Hypotonic stimula-tion(47％)significantly activated volume-sensitive chloride currents in K562 cells(P＜0.01).Extracellular applica-tion of chloride channel blockers ATP(10 mmol/L)or NPPB(50 μmol/L)inhibited the hypotonicity-activated currents(P＜0.05),and the inhibition was reversible upon washout.The current density activated by hypotonic stimulation was higher in SP cells than in NSP cells(P＜0.05),and the latency to peak activation was shorter in SP cells(P＜0.05).Whole-cell membrane capacitance showed no significant difference between SP and NSP cells(P＞0.05).Conclusion Volume-sensitive chloride currents exist in K562 cells,and their activity is significantly higher in SP cells compared with NSP cells.
Keywords：chronic myeloid leukemiaside population cellsvolume-sensitive chloride current
Publication Date：2025-10-15
Online Publishing Date：2025-11-28(First online date of this platform, not the publication date of the document)
Pages：7( 1514-1520 )