PubMed 20438714

Referenced in: none

Automatically associated channels: BKβ , Cav1.3 , Kir2.1 , Kv1.4 , Kv2.1 , Kv3.1 , Kv4.2 , Kv7.1 , Nav1.7

Title: High expression of large-conductance Ca(2+)-activated K(+) channel in the CD133(+) subpopulation of SH-SY5Y neuroblastoma cells.

Authors: Ji Hyun Park, Su Jung Park, Mi Kyung Chung, Kyoung Hwa Jung, Mi Ran Choi, Yangmi Kim, Young Gyu Chai, Sung Joon Kim, Kyoung Sun Park

Journal, date & volume: , 2010 May 7 , ,

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/20438714

Abstract
Solid tumors contain a population of cancer stem cells (CSCs), and CD133 is widely used as a CSCs marker. We investigated the differences between CD133(+) and CD133(-) cells from the neuroblastoma cell line SH-SY5Y in terms of the expressions of voltage-gated ion channels. A CD133(+) enriched (>60%) population was isolated, and a subsequent whole-cell voltage-clamp study showed that these cells predominantly express TEA-sensitive outward K(+) currents (I(K,TEA)) and TTX-sensitive voltage-gated inward Na(+) currents (I(Na)). Cell-attached single channel recordings demonstrated higher density of large-conductance (155pS) channel in CD133(+) cells than in CD133(-) cells. The TEA-sensitivity and single channel conductance indicated the large-conductance Ca(2+)-activated K(+) channels (BK(Ca)). Furthermore, RT-PCR analysis of 22 transcripts of voltage-gated ion channels in SH-SY5Y cells showed the expressions of Cav1.3, Kir2.1, Kv1.4, Kv2.1, Kv4.2, Kv7.1, BK(Ca), and Nav1.7, and those of BK(Ca) and Nav1.7 were higher in CD133(+) than in CD133(-) cells. In addition, the increase of cytosolic Ca(2+) concentration ([Ca(2+)](c)) in response to ionomycin (a Ca(2+) ionophore) was higher and more sustained in CD133(+) than in CD133(-) cells. Plausibly membrane hyperpolarization via BK(Ca) might be responsible for the augmented Ca(2+) influx observed in CD133(+) cells. The physiological implications of the differential expression of BK(Ca) and Nav1.7 in CSCs require further investigation.