Radiation effect mediated by divalent cations in human lung cancer cells in vitro

Abstract

Radiotherapy has become a major treatment option for small cell lung carcinoma (SCLC) and locally advanced non SCLC (NSCLC). Moreover, divalent cations show a potential role in cancer therapy, which have become attractive nowadays. To explore the potential combination role of irradiation with divalent cations treatment in human lung cancer cells in vitro, human NSCLC A549 and SCLC NCI-H446 cells were irradiated with 2 Gy X-rays under 1 mM calcium (Ca2+), magnesium (Mg2+) or zinc (Zn2+) treatments. It was found that the Ca2+ and Mg2+ could inhibit activating ERK pathway, blocking cell proliferation, enhancing DNA damage, suppressing DNA repair capacity, strengthening p53 activation and increasing apoptosis induced by irradiation in lung cancer cells. On opposite, Zn2+ showed a negative regulation in radiation effect. Moreover, Ca2+, Mg2+ and Zn2+ could inhibit p38 activation and cell invasion induced by irradiation. These results suggest that divalent cations of Ca2+ and Mg2+ could potentiate radiation effect in lung cancer cells, which warrants further investigation for this combination effect of irradiation and divalent cations in potential clinical applications.