title: KCa3.1 (IK) modulates pancreatic cancer cell migration, invasion and proliferation: anomalous effects on TRAM-34.
abstract: In the recent decades, ion channels became the focus of cancer biologists, as many channels are overexpressed in tumour tissue and functionally they are linked to abnormal cell behaviour with processes including apoptosis, chemo- and radioresistance, proliferation and migration. KCa3.1 is a Ca2+-activated K+channel that plays a central role in tumour progression in many cancer types. Therefore, the aim of the present study was to investigate KCa3.1 expression in pancreatic cancer cells and assess possible implications to disease progression. Using qPCR technique, we found abundant expression of KCa3.1 in pancreatic cancer cell lines. Patch clamp measurements on MiaPaCa-2 cells revealed a Ca2+-activated K+current that matched biophysical characteristics as described for KCa3.1. Moreover, the current was sensitive to the commonly used channel modulators TRAM-34, clotrimazole and DC-EBIO, and it was abolished following transient gene knockdown of KCa3.1. We utilized both pharmacology and RNAi to assess a possible role of the channel in tumour cell behaviour. We found that the channel supported MiaPaCa-2 cell proliferation. Using RNAi protocols, we also identified KCa3.1 as important entity in cell invasion. However, TRAM-34 had unexpected stimulatory effects on cell migration and invasion estimated in various assays. Moreover, TRAM-34 increased intracellular Ca2+. In conclusion, we found prominent functional expression of KCa3.1 in pancreatic cancer cells. We provide evidence that the channel has a key role in cell proliferation and for the first time identify KCa3.1 as important entity in PDAC cell migration. We further reveal anomalous effects of TRAM-34.
authors.affiliation: Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, Copenhagen, Denmark.|Division of Cell and Molecular Biology, Neuroscience Solutions to Cancer Research Group, Imperial College London, London, UK.
authors.forename: B
authors.initials: B
authors.lastname: Bonito
authors.affiliation: Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, Copenhagen, Denmark.|Division of Cell and Molecular Biology, Neuroscience Solutions to Cancer Research Group, Imperial College London, London, UK.
authors.forename: D R P
authors.initials: DR
authors.lastname: Sauter
authors.affiliation: Institut für Physiologie II, University of Münster, Robert-Koch-Str. 27b, 48149, Münster, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Schwab
authors.affiliation: Division of Cell and Molecular Biology, Neuroscience Solutions to Cancer Research Group, Imperial College London, London, UK.
authors.forename: M B A
authors.initials: MB
authors.lastname: Djamgoz
authors.affiliation: Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, Copenhagen, Denmark. INovak@bio.ku.dk.
authors.forename: I
authors.identifier: 0000-0002-8917-8010
authors.initials: I
authors.lastname: Novak
mesh_terms: D000200:Action Potentials; D000230:Adenocarcinoma / Q000378:metabolism*; D001562:Benzimidazoles / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects*; D003022:Clotrimazole / Q000494:pharmacology; D006801:Humans; D051660:Intermediate-Conductance Calcium-Activated Potassium Channels / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D010190:Pancreatic Neoplasms / Q000378:metabolism*; D026902:Potassium Channel Blockers / Q000494:pharmacology*; D011720:Pyrazoles / Q000494:pharmacology*
chemical_list: D001562:Benzimidazoles; D051660:Intermediate-Conductance Calcium-Activated Potassium Channels; C496923:KCNN4 protein, human; D026902:Potassium Channel Blockers; D011720:Pyrazoles; C411671:TRAM 34; D003022:Clotrimazole; C102635:1-ethyl-2-benzimidazolinone; D002118:Calcium
keywords: Clotrimazole; DC-EBIO; KCNN4; KCa3.1; Migration; Pancreatic ductal adenocarcinoma; TRAM-34