Decrease in Ca2+-activated K+ conductance in differentiated C6-glioma cells.
Ca2+-activated K+ channels were studied in C6-glioma cells in an attempt to correlate changes in expression with cell proliferation and differentiation. In this study, we treated C6-glioma cells with thapsigargin for 48 h. Cell proliferation was markedly inhibited, and cell morphology changed from round to a spindle differentiated shape. Furthermore, intracellular calcium concentration was initially increased during acute treatment with thapsigargin. The internal [Ca2+]i pool was eventually depleted after a 48-h thapsigargin treatment. We have characterized Ca2+-activated K+ currents in less differentiated C6 cells. After differentiation of C6 cells induced by thapsigargin, Ca2+-activated K+ currents were selectively suppressed. These data lend further support to the notion that the expression of Ca2+-activated K+ channels is intimately associated with the proliferation of C6-glioma cells, and the suppression of Ca2+-activated K+ channels coincides with the inhibition of proliferation and subsequent induction of cell differentiation.
Kuo
Tsun-Cheng
TC
Department of Cosmetic Science, Chia-Nan University of Pharmacy and Science, Tainan, Taiwan. kuotsung@mall.chna.edu.tw
Lin-Shiau
Shoei-Yn
SY
D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D005910:Glioma; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D024681:Potassium Channels, Calcium-Activated / Q000502:physiology*; D019284:Thapsigargin / Q000494:pharmacology
D024681:Potassium Channels, Calcium-Activated; D019284:Thapsigargin