cAMP-PKA inhibition of SK3 channel reduced both Ca2+ entry and cancer cell migration by regulation of SK3-Orai1 complex.
SK3 channel mediates the migration of various cancer cells. When expressed in breast cancer cells, SK3 channel forms a complex with Orai1, a voltage-independent Ca(2+) channel. This SK3-Orai1 complex associates within lipid rafts where it controls a constitutive Ca(2+) entry leading to cancer cell migration and bone metastases development. Since cAMP was found to modulate breast cancer cell migration, we hypothesized that this could be explained by a modulation of SK3 channel activity. Herein, we study the regulation of SK3 channel by the cAMP-PKA pathway and the consequences for SK3-dependent Ca(2+) entry and cancer cell migration. We established that the beta-adrenergic receptor agonist, isoprenaline, or the direct adenylyl cyclase activator forskolin alone or in combination with the PDE4 inhibitor, CI-1044, decreased SK3 channel activity without modifying the expression of SK3 protein at the plasma membrane. Forskolin and CI-1044 reduced the SK3-dependent constitutive Ca(2+) entry and the SK3-dependent migration of MDA-MB-435s cells. PKA inhibition with KT 5720 reduced: (1) the effect of forskolin and CI-1044 by 50 % on Ca(2+) entry and (2) SK3 activity by inhibiting the serine phosphorylation of SK3. These cAMP-elevating agents displaced Orai1 protein outside lipid rafts in contrast to SK3, which remained in the lipid rafts fractions. All together, these results show that activation of the cAMP-PKA pathway decreases SK3 channel and SK3-Orai1 complex activities, leading to a decrease in both Ca(2+) entry and cancer cell migration. This work supports the potential use of cAMP-elevating agents to reduce cancer cell migration and may provide novel opportunities to address/prevent bone metastasis.
Inserm, UMR1069 "Nutrition, Croissance et Cancer", Tours, 37032, France.
Lucie
L
Clarysse
Maxime
M
Guéguinou
Marie
M
Potier-Cartereau
Grégoire
G
Vandecasteele
Philippe
P
Bougnoux
Stephan
S
Chevalier
Aurélie
A
Chantôme
Christophe
C
Vandier
D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D001381:Azepines / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism*; D002227:Carbazoles / Q000494:pharmacology; D045744:Cell Line, Tumor; D002465:Cell Movement; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D007545:Isoproterenol / Q000494:pharmacology; D021962:Membrane Microdomains / Q000378:metabolism; D009536:Niacinamide / Q000031:analogs & derivatives / Q000494:pharmacology; D000071740:ORAI1 Protein; D058988:Phosphodiesterase 4 Inhibitors / Q000494:pharmacology; D011485:Protein Binding; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011758:Pyrroles / Q000494:pharmacology; D051640:Small-Conductance Calcium-Activated Potassium Channels / Q000378:metabolism*
D000318:Adrenergic beta-Agonists; D001381:Azepines; D015220:Calcium Channels; D002227:Carbazoles; C406328:KCNN3 protein, human; D000071740:ORAI1 Protein; C510746:ORAI1 protein, human; D058988:Phosphodiesterase 4 Inhibitors; D047428:Protein Kinase Inhibitors; D011758:Pyrroles; D051640:Small-Conductance Calcium-Activated Potassium Channels; D005576:Colforsin; D009536:Niacinamide; C057416:KT 5720; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D007545:Isoproterenol; C418118:CI 1044; D002118:Calcium