title: Novel perspectives in cancer therapy: Targeting ion channels.
abstract: By controlling ion fluxes at multiple time scales, ion channels shape rapid cell signals, such as action potential and synaptic transmission, as well as much slower processes, such as mitosis and cell migration. As is currently increasingly recognized, a variety of channel types are involved in cancer hallmarks, and regulate specific stages of neoplastic progression. Long-term in vitro work has established that inhibition of these ion channels impairs the growth of cancer cells. Recently, these studies have been followed up in vivo, hence revealing that ion channels constitute promising pharmacological targets in oncology. The channel proteins can be often accessed from the extracellular milieu, which allows use of lower drug doses and decrease untoward toxicity. However, because of the central physiological roles exerted by ion channels in excitable cells, other types of side effects may arise, the gravest of which is cardiac arrhythmia. A paradigmatic case is offered by Kv11.1 (hERG1) channels. HERG1 blockers attenuate the progression of both hematologic malignancies and solid tumors, but may also lead to the lengthening of the electrocardiographic QT interval, thus predisposing the patient to ventricular arrhythmias. These side effects can be avoided by specifically inhibiting the channel isoforms which are highly expressed in certain tumors, such as Kv11.1B and the neonatal forms of voltage-gated Na(+) channels. Preclinical studies are also being explored in breast and prostate cancer (targeting voltage-gated Na(+) channels), and gliomas (targeting CLC-3). Overall, the possible approaches to improve the efficacy and safety of ion channel targeting in oncology include: (1) the development of specific inhibitors for the channel subtypes expressed in specific tumors; (2) drug delivery into the tumor by using antibodies or nanotechnology-based approaches; (3) combination regimen therapy and (4) blocking specific conformational states of the ion channel. We believe that expanding this relatively neglected field of oncology research might lead to unforeseen therapeutic benefits for cancer patients.
authors.affiliation: Department of Experimental and Clinical Medicine, University of Florence, Viale Morgagni 50, Florence, 50134, Italy. Electronic address: annarosa.arcangeli@unifi.it.
authors.forename: Annarosa
authors.initials: A
authors.lastname: Arcangeli
authors.affiliation: Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milano, 20126, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Becchetti
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D016503:Drug Delivery Systems; D004353:Drug Evaluation, Preclinical / Q000379:methods; D005260:Female; D006801:Humans; D007473:Ion Channels / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D058990:Molecular Targeted Therapy; D009369:Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents; D007473:Ion Channels
keywords: Arrhythmia; Combination therapy; K(v)11; K(v)12; Leukemia; Nanoparticles; Side effects; Tumor; hERG