Sphingosine 1-phosphate and human ether-a′-go-go-related gene potassium channels modulate migration in human anaplastic thyroid cancer cells

Abstract

Anaplastic thyroid cancer (ATC) is the most aggressive form of human thyroid cancer, lacking any effective treatment. Sphingosine 1-phosphate (S1P) receptors and human ether-a 0 -go-go-related gene (HERG (KCNH2)) potassium channels are important modulators of cell migration. In this study, we have shown that the S1P 1-3 receptors are expressed in C643 and THJ-16T human ATC cell lines, both at mRNA and protein level. S1P inhibited migration of these cells and of follicular FTC-133 thyroid cancer cells. Using the S1P 1,3 inhibitor VPC-23019, the S1P 2 inhibitor JTE-013, and the S1P 2 receptor siRNA, we showed that the effect was mediated through S1P 2 . Treatment of the cells with the Rho inhibitor C3 transferase abolished the effect of S1P on migration. S1P attenuated Rac activity, and inhibiting Rac decreased migration. Sphingosine kinase inhibitor enhanced basal migration of cells, and addition of exogenous S1P inhibited migration. C643 cells expressed a nonconducting HERG protein, and S1P decreased HERG protein expression. The HERG blocker E-4031 decreased migration. Interestingly, downregulating HERG protein with siRNA decreased the basal migration. In experiments using HEK cells overexpressing HERG, we showed that S1P decreased channel protein expression and current and that S1P attenuated migration of the cells. We conclude that S1P attenuates migration of C643 ATC cells by activating S1P 2 and the Rho pathway. The attenuated migration is also, in part, dependent on a S1P-induced decrease of HERG protein.

Ablation of Sphingosine 1-Phosphate Receptor Subtype 3 Impairs Hippocampal Neuron Excitability In vitro and Spatial Working Memory In vivo

“…For example, S1P activates inwardly rectifying K + currents (I K.ACh ) in ventricular myocytes with the involvement of S1P 1 and S1P 3 (Landeen et al, 2008) and the SUR2/K ir 6.2 channel via S1P 3 in mouse ventricular fibroblasts (Benamer et al, 2009, 2011). Although a direct regulatory effect of S1P 3 on potassium channel activity is not supported by the present results, this leaves three alternative possibilities as explanations for the significantly reduced input resistance and firing frequency in ${\text{S1P}}_3^{-/-}$ mice: first, other members of the large potassium channel family may be targeted by S1P 3 receptor signaling similar to a study in human anaplastic thyroid cancer cells where S1P down-regulates Kv11.1 regulation via S1P 2 (Asghar et al, 2012). Second, protein expression may be deregulated by mechanisms independent of transcription e.g., by microRNAs as shown for BK potassium channels (Pietrzykowski et al, 2008) or third, posttranslational modifications of ion channels such as protein phosphorylation or trafficking may be affected by S1P 3 receptor depletion (Johnston et al, 2010).…”

Transient Receptor Potential Canonical 1 (TRPC1) Channels as Regulators of Sphingolipid and VEGF Receptor Expression

“…Migration and Invasion Assays-Migration and invasion assays were performed as described previously (18). In some experiments, the cells were preincubated with 10 M KN-93, 100 M W-13 hydrochloride, or 2 M GsMTx-4 for 1 h, respectively, at 37°C.…”

Sphingosine 1-phosphate attenuates MMP2 and MMP9 in human anaplastic thyroid cancer C643 cells: Importance of S1P2

“…Previously, we have shown that S1P (100 nM, 6 h) inhibits migration and invasion of human anaplastic thyroid cancer C643 and follicular thyroid cancer FTC-133 cells towards lipid-stripped serum. This attenuated migration is mediated by S1P 2 and the Rho-ROCK pathway [ 10 ]. Interestingly, S1P promotes migration and invasion in human follicular thyroid cancer ML-1 cells [ 6 – 8 , 21 ] and increases the secretion and activity of MMP2 and MMP9 through S1P 1,3 [ 19 ].…”

“…Invasion assays were performed as described elsewhere [ 10 ]. Cells were grown in 0.2% FAF-BSA-containing serum-free medium (SFM) overnight before the start of an experiment.…”

“…In many cancer cells, including follicular thyroid cancer ML-1 cells, S1P promotes migration and invasion by activating S1P 1,3 and downstream PI3K-Akt and Rac signaling pathways [ 3 – 8 ]. However, S1P inhibits migration and invasion by activating S1P receptor 2 and the downstream Rho-ROCK signaling pathway and by inhibiting Rac activity in many cell types [ 9 ], including human anaplastic thyroid cancer C643 cells [ 10 ]. In some cell types, however, S1P 2 can also enhance migration [ 11 ].…”