Overexpression of acid-sensing ion channel 1a (ASIC1a) promotes breast cancer cell proliferation, migration and invasion

BACKGROUND: The microenvironment of various tumor tissues is acidic. Acid-sensing ion channels (ASICs) are a class of ligand-gated ion channels which are sensitive to extracellular protons and are often highly expressed in tumor tissues. Breast cancer, whose extracellular microenvironment is thought to be acidic, is the most common cancer type among females in the world. METHODS: Thirty breast cancer tissues and adjacent normal tissues of patients were collected from 2009 to 2015 at the Xinhua hospital affiliated to Shanghai Jiao Tong University School of Medicine. The expression of acid-sensing ion channel 1a (ASIC1a), a subtype of ASICs family, was detected by immunohistochemistry in breast cancer tissues, and the effect of ASIC1a on the physiological activity of tumor cells was analyzed in vitro and in vivo experiments. RESULTS: In this study, it was found that ASIC1a is highly expressed in the tissues of breast cancer patients. In vitro experiments revealed that down-regulation of ASIC1a by its antagonist PcTx-1 or ASIC1a siRNA could significantly weaken the migration, proliferation and invasion of tumor cells. In vivo studies, down-regulation or inhibition of the ASIC1a could inhibit breast tumor growth. CONCLUSIONS: The high expression of ASIC1a might be related to the enhanced biological activity of breast cancer cells. Whether ASIC1a is a potential therapeutic target for some types of breast cancer deserves further study.