Volume-regulated chloride channel regulates cell proliferation and is involved in the possible interaction between TMEM16A and LRRC8A in human metastatic oral squamous cell carcinoma cells

• Published in: European journal of pharmacology Vol. 895; p. 173881
• Main Authors: Yoshimoto, Shohei, Matsuda, Miho, Kato, Kenichi, Jimi, Eijiro, Takeuchi, Hiroshi, Nakano, Shuji, Kajioka, Shunichi, Matsuzaki, Etsuko, Hirofuji, Takao, Inoue, Ryuji, Hirata, Masato, Morita, Hiromitsu
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.03.2021
• Subjects: Anoctamin-1 - antagonists & inhibitors; Anoctamin-1 - genetics; Anoctamin-1 - metabolism; Antineoplastic Agents - pharmacology; Apoptosis; Bestrophins - genetics; Bestrophins - metabolism; Cell Line, Tumor; Cell proliferation; Cell Proliferation - drug effects; Chloride Channels - antagonists & inhibitors; Chloride Channels - genetics; Chloride Channels - metabolism; Cyclopentanes - pharmacology; DCPIB; Gene Expression Regulation, Neoplastic; Humans; Indans - pharmacology; Ion Channel Gating; LRRC8A; Membrane Proteins - antagonists & inhibitors; Membrane Proteins - genetics; Membrane Proteins - metabolism; Neoplasm Proteins - antagonists & inhibitors; Neoplasm Proteins - genetics; Neoplasm Proteins - metabolism; Oral cancer; Protein Binding; Signal Transduction; Squamous Cell Carcinoma of Head and Neck - drug therapy; Squamous Cell Carcinoma of Head and Neck - genetics; Squamous Cell Carcinoma of Head and Neck - metabolism; Squamous Cell Carcinoma of Head and Neck - secondary; TMEM16A; Tongue Neoplasms - drug therapy; Tongue Neoplasms - genetics; Tongue Neoplasms - metabolism; Tongue Neoplasms - pathology; Volume-regulated chloride channel; Cell proliferation; LRRC8A; TMEM16A; Volume-regulated chloride channel; Oral cancer; DCPIB
• ISSN: 0014-2999; 1879-0712
• DOI: 10.1016/j.ejphar.2021.173881

Volume-regulated anion channels (VRACs), expressed in various cells, play an important role in cell volume regulation. Despite being physiologically defined almost half a century ago, only the molecular candidates of VRAC, TMEM16A, LRRC8A, and bestrophin-1 (BEST1), are known. Here, we aimed to explore the functional significance of VRAC in, HST-1, an oral squamous cell carcinoma (OSCC) cell line. Cell proliferation assays, RT-PCR, Western blot, and flow cytometry were used to estimate changes in gene expression and cell proliferation. Ion channel activity was recorded using the patch-clamp technique. Specific genes were knocked-down by siRNA assays. VRAC, identified as a hypotonicity-induced current, was highly functional and associated with the proliferation of HST-1 cells but not of HaCaT (a normal keratinocyte) cells. The pharmacological profile of VRAC in HST-1 was similar to that reported previously. DCPIB, a specific VRAC inhibitor, completely inhibited VRAC and proliferation of HST-1 cells, eventually leading to apoptosis. VRAC in HST-1 was attenuated by the knockdown of TMEM16A and LRRC8A, while knockdown of BEST1 affected cell proliferation. In situ proximity ligation assay showed that TMEM16A and LRRC8A co-localized under isotonic conditions (300 mOsM) but were separated under hypotonic conditions (250 mOsM) on the plasma membrane. We have found that VRAC acts to regulate the proliferation of human metastatic OSCC cells and the composition of VRAC may involve in the interactions between TMEM16A and LRRC8A in HST-1 cells. •We aimed to identify the functional significance of volume-regulated anion channels (VRAC) in human OSCC cells.•VRAC in HST-1 likely involves the functional interaction of TMEM16A and LRRC8A, regulating the proliferative potential.•DCPIB, a specific VRAC inhibitor, suppressed both VRAC and the proliferation of HST-1 cells.