SKF95365 induces apoptosis and cell-cycle arrest by disturbing oncogenic Ca2+ signaling in nasopharyngeal carcinoma cells

Abstract

Background: Aberrant modulation of store-operated calcium ions (Ca2+) entry promotes the progression of human malignancies. Previously, we reported that the blockage of store-operated Ca2+ entry inhibited epidermal growth factor (EGF)-stimulated migration and distant metastasis in nasopharyngeal carcinoma (NPC) cells. However, the effects of pharmacological blocker on other Ca2+ signaling-regulated malignant characteristics in NPC cells remained poorly understood. Methods: We examined the effects of SKF96365, an inhibitor of store-operated Ca2+ channel, on EGF-launched Ca2+ signaling in two NPC cell lines. We determined the effects of SKF96365 on cell proliferation, colony formation, apoptosis, and cell-cycle status in vitro. We further elucidated the antitumor activity of SKF96365 in xenograft-bearing mice. Results: It was found that SKF96365 disturbed the thapsigargin (TG)-stimulated Ca2+ release from endoplasmic reticulum and the subsequent Ca2+ influx. SKF96365 alone stimulated Ca2+responses merely due to endoplasmic reticulum-released Ca2+. SKF96365 promoted cell mortality, inhibited colony formation, and induced apoptosis and cell-cycle arrest, while blunting the EGF-evoked Ca2+ signaling. Furthermore, we confirmed that SKF96365 reduced NPC xenograft growth while activating caspase-7-related apoptotic pathway. Conclusion: SKF96365 exerts multiple antitumor activities through the distraction on the oncogenic Ca2+ signaling transduction in NPC cells.