ET-1 inhibits B-16 murine melanoma cell migration by decreasing K(+) currents.
Cell migration is mediated by ion channels and transporters, and plays crucial roles in a variety of physiological and pathological processes. Previously, our studies have shown that a Ca(2+)-regulated K(+) current exists in B-16 murine melanoma cells, and that endothelin-1 (ET-1) inhibits the K(+) current via a PKC-dependent pathway. In the present study, patch-clamp whole-cell recording and transwell migration assays were used to examine the effects of ET-1 on B-16 murine melanoma cell migration. ET-1 (100 nM in the injection pipette and 10 nM in the incubation medium) decreased the K(+) current amplitude by 33.0 +/- 2.5% and inhibited migration of B-16 cells by 57.4 +/- 9.4%. Similarly, the Ca(2+)-regulated K(+) channel blockers, BaCl(2) and quinidine, decreased the K(+) current by 20.5 +/- 1.0% and 36.6 +/- 1.2%, respectively, and slowed migration of B-16 melanoma cells by 37.1 +/- 8.6% and 42.7 +/- 8.8%, respectively. The effect of ET-1 on the K(+) current and cell migration was simulated by ET-3. In contrast, the K(+) channel opener, diclofenac, increased the K(+) current by 128.8 +/- 11.7%, 257.4 +/- 35.8% at concentrations of 1 and 5 mM, respectively. Likewise, the migration of B-16 murine melanoma cells dramatically increased by 75.6 +/- 12.7% in the presence of 100 microM diclofenac in incubation medium. Furthermore, the ET-1- and ET-3-induced inhibition of K(+) current and migration was abrogated by diclofenac. In the presence of diclofenac, ET-1 only reduced the K(+) current amplitude by 10.6 +/- 1.1%, and slowed B-16 cell migration by only 10.8 +/- 8.9%. The results suggest that the K(+) channel-dependent migration of B-16 melanoma cells is modulated by ET-1. Cell Motil.
Liu
Lin-Yun
LY
Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai, China.
Hu
Chang-Long
CL
Ma
Lai-Ji
LJ
Zhang
Zhi-Hong
ZH
Mei
Yan-Ai
YA
D000818:Animals; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology*; D004008:Diclofenac / Q000494:pharmacology; D019332:Endothelin-1 / Q000378:metabolism* / Q000494:pharmacology; D008546:Melanoma, Experimental / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D011188:Potassium / Q000037:antagonists & inhibitors / Q000378:metabolism*; D015221:Potassium Channels / Q000187:drug effects
D019332:Endothelin-1; D015221:Potassium Channels; D004008:Diclofenac; D011188:Potassium