title: Correlation between potassium channel expression and sensitivity to drug-induced cell death in tumor cell lines.
abstract: Plasma membrane (PM) and mitochondrial (mt) ion channels - particularly potassium channels - became oncological targets soon after the discovery that they are involved both in the regulation of proliferation and apoptosis. Some members of the Kv Shaker family, namely Kv1.1, Kv1.3, Kv1.5 and Kv11.1 (Herg), and the intermediate-conductance calcium-activated potassium KCa3.1 (IK) channels have been shown to contribute to apoptosis in various cell lines. Kv1.3, Kv1.5 and IK are located in the plasma membrane but also in the mitochondrial inner membrane, where they participate in apoptotic signalling. Interestingly, an altered protein expression of some of the channels mentioned above has been reported in neoplastic cell lines/tissues, but a systematic quantification addressing the protein expression of the above potassium channels in tumor cell lines of different origin has not been carried out yet. In the present study we investigated whether expression of specific potassium channels, at the mRNA and protein level, can be correlated with cell sensitivity to various apoptotic stimuli, including chemotherapeutic drugs, in a panel of cancer cell lines. The results show correlation between the protein expression of the Kv1.1 and Kv1.3 channels and susceptibility to death upon treatment with staurosporine, C2-ceramide and cisplatin. Furthermore, we investigated the correlation between Kv channel expression and sensitivity to three distinct membrane-permeant Kv1.3 inhibitors, since these drugs have recently been shown to be able to induce apoptosis and also reduce tumor volume in an in vivo model. Higher protein expression of Kv1.3 significantly correlated with lower cell survival upon treatment with clofazimine, one of the Kv1.3 inhibitors. These results suggest that expression of Kv1.1 and Kv1.3 sensitizes tumour cells of various origins to cytotoxins. Data reported in this work regarding potassium channel protein expression in different cancer cell lines may be exploited for pharmacological manipulation aiming to affect proliferation/apoptosis of cancer cells.
authors.forename: Luigi
authors.initials: L
authors.lastname: Leanza
authors.forename: Paul
authors.initials: P
authors.lastname: O'Reilly
authors.forename: Anne
authors.initials: A
authors.lastname: Doyle
authors.forename: Elisa
authors.initials: E
authors.lastname: Venturini
authors.forename: Mario
authors.initials: M
authors.lastname: Zoratti
authors.forename: Eva
authors.initials: E
authors.lastname: Szegezdi
authors.affiliation: Department of Biology, University of Padova, Italy. ildi@civ.bio.unipd.it.
authors.forename: Ildiko
authors.initials: I
authors.lastname: Szabo
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D016923:Cell Death / Q000187:drug effects; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D002945:Cisplatin / Q000494:pharmacology; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D051662:Kv1.1 Potassium Channel / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D051664:Kv1.3 Potassium Channel / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D009369:Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D026902:Potassium Channel Blockers / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D013110:Sphingosine / Q000031:analogs & derivatives / Q000494:pharmacology; D019311:Staurosporine / Q000494:pharmacology; D047368:Tumor Burden / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents; D051664:Kv1.3 Potassium Channel; C064769:N-acetylsphingosine; D026902:Potassium Channel Blockers; D012333:RNA, Messenger; D051662:Kv1.1 Potassium Channel; D019311:Staurosporine; D013110:Sphingosine; D002945:Cisplatin