EFFECT OF OUABAIN ON THE DETACHMENT OF H23 LUNG CANCER CELL

Abstract

A human steroid hormone, ouabain, has been shown to play a role in several types of cancer cell behavior; however, its effects on cancer metastasis are largely unknown. Here, we demonstrate in human lung cancer cells that sub-toxic concentrations of ouabain facilitate cancer cell detachment from the extracellular matrix. Ouabain at concentrations of 0-10 pM significantly enhances cell detachment in dose- and time- dependent manners, while having minimal effect on cell viability. The detachment-inducing effect of ouabain was found to be mediated through focal-adhesion kinase and ATP-dependent tyrosine kinase pathways. Alpha-5 and Beta-1 integrins were found to be down-regulated in response to ouabain treatment. Since detachment of cancer cells is a prerequisite process for metastasis to begin, these insights benefit our understanding of the molecular basis of cancer biology.