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Eskandari N, Gentile S. Potassium channels activity unveils cancer vulnerability. CURRENT TOPICS IN MEMBRANES 2023; 92:1-14. [PMID: 38007264 DOI: 10.1016/bs.ctm.2023.09.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2023]
Abstract
"No cell could exist without ion channels" (Clay Armstrong; 1999). Since the discovery in the early 1950s, that ions move across biological membranes, the idea that changes of ionic gradients can generate biological signals has fascinated scientists in any fields. Soon later (1960s) it was found that ionic flows were controlled by a class of specific and selective proteins called ion channels. Thus, it became clear that the concerted activities of these proteins can initiate, arrest, and finely tune a variety of biochemical cascades which offered the opportunity to better understand both biology and pathology. Cancer is a disease that is notoriously difficult to treat due its heterogeneous nature which makes it the deadliest disease in the developed world. Recently, emerging evidence has established that potassium channels are critical modulators of several hallmarks of cancer including tumor growth, metastasis, and metabolism. Nevertheless, the role of potassium ion channels in cancer biology and the therapeutic potential offered by targeting these proteins has not been explored thoroughly. This chapter is addressed to both cancer biologists and ion channels scientists and it aims to shine a light on the established and potential roles of potassium ion channels in cancer biology and on the therapeutic benefit of targeting potassium channels with activator molecules.
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Affiliation(s)
- Najmeh Eskandari
- Department of Cell and Molecular Pharmacology & Experimental Therapeutics, Medical University of South Carolina, Charleston, SC, United States
| | - Saverio Gentile
- Department of Cell and Molecular Pharmacology & Experimental Therapeutics, Medical University of South Carolina, Charleston, SC, United States.
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Guidelli R. An Insight into the Potassium Currents of hERG and Their Simulation. Molecules 2023; 28:molecules28083514. [PMID: 37110748 PMCID: PMC10142355 DOI: 10.3390/molecules28083514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 03/27/2023] [Accepted: 04/11/2023] [Indexed: 04/29/2023] Open
Abstract
By assuming that a stepwise outward movement of the four S4 segments of the hERG potassium channel determines a concomitant progressive increase in the flow of the permeant potassium ions, the inward and outward potassium currents can be simulated by using only one or two adjustable (i.e., free) parameters. This deterministic kinetic model differs from the stochastic models of hERG available in the literature, which usually require more than 10 free parameters. The K+ outward current of hERG contributes to the repolarization of the cardiac action potential. On the other hand, the K+ inward current increases with a positive shift in the transmembrane potential, in apparent contrast to both the electric and osmotic forces, which would concur in moving K+ ions outwards. This peculiar behavior can be explained by the appreciable constriction of the central pore midway along its length, with a radius < 1 Å and hydrophobic sacks surrounding it, as reported in an open conformation of the hERG potassium channel. This narrowing raises a barrier to the outward movement of K+ ions, inducing them to move increasingly inwards under a gradually more positive transmembrane potential.
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Affiliation(s)
- Rolando Guidelli
- Retired Professor, Department of Chemistry "Ugo Schiff", Florence University, Via della Lastruccia 3, Sesto Fiorentino, 50019 Firenze, Italy
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Calderon-Rivera A, Gomez K, Loya-López S, Wijeratne EK, Stratton H, Tang C, Duran P, Masterson K, Alsbiei O, Gunatilaka AL, Khanna R. Betulinic acid analogs inhibit N- and T-type voltage-gated calcium channels to attenuate nerve-injury associated neuropathic and formalin models of pain. NEUROBIOLOGY OF PAIN (CAMBRIDGE, MASS.) 2023; 13:100116. [PMID: 36687466 PMCID: PMC9853350 DOI: 10.1016/j.ynpai.2023.100116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/10/2023] [Accepted: 01/11/2023] [Indexed: 01/15/2023]
Abstract
Over the past three decades, there has been a significant growth in the use of natural products, with approximately 80% of individuals using them for some aspect of primary healthcare. Our laboratories have identified and studied natural compounds with analgesic effects from dry land plants or their associated fungus during the past ten years. Here, we isolated and characterized thirteen betulin analogs and fifteen betulinic acid analogs for their capacity to prevent calcium influx brought on by depolarization in sensory neurons. The in vitro inhibition of voltage-gated calcium channels by the top drugs was then assessed using whole cell patch clamp electrophysiology. In vivo experiments, conducted at two sites, evaluated the best compound in acute and tonic, neuropathic, inflammatory, post-operative and visceral models of pain. We found that the betulinic acid analog 8 inhibited calcium influx in rat dorsal root ganglion neurons by inhibiting N- (CaV2.2) and T- (CaV3) type voltage-gated calcium channels. Moreover, intrathecal delivery of analog 8 had analgesic activity in both spared nerve injury model of neuropathic pain and acute and tonic pain induced by formalin. The results presented herein highlight the potential antinociceptive properties of betulinic acid analog 8 and set the stage for the development of novel non-opioid pain therapeutics based on the triterpenoid scaffold of betulinic acid.
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Affiliation(s)
- Aida Calderon-Rivera
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY, United States
- NYU Pain Research Center, New York University, New York, NY, United States
| | - Kimberly Gomez
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY, United States
- NYU Pain Research Center, New York University, New York, NY, United States
| | - Santiago Loya-López
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY, United States
- NYU Pain Research Center, New York University, New York, NY, United States
| | - E.M. Kithsiri Wijeratne
- Natural Products Center, School of Natural Resources and the Environment, College of Agriculture and Life Sciences, The University of Arizona, Tucson, AZ, United States
| | - Harrison Stratton
- Department of Pharmacology, College of Medicine, The University of Arizona, Tucson, AZ, United States
| | - Cheng Tang
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY, United States
- NYU Pain Research Center, New York University, New York, NY, United States
| | - Paz Duran
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY, United States
- NYU Pain Research Center, New York University, New York, NY, United States
| | - Kyleigh Masterson
- NYU Pain Research Center, New York University, New York, NY, United States
| | - Omar Alsbiei
- NYU Pain Research Center, New York University, New York, NY, United States
| | - A.A. Leslie Gunatilaka
- Natural Products Center, School of Natural Resources and the Environment, College of Agriculture and Life Sciences, The University of Arizona, Tucson, AZ, United States
| | - Rajesh Khanna
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY, United States
- NYU Pain Research Center, New York University, New York, NY, United States
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