Inhibition of TMEM16A Expression Suppresses Growth and Invasion in Human Colorectal Cancer Cells

Abstract

Metastasis leads to poor prognosis in colorectal cancer patients, and there is a growing need for new therapeutic targets. TMEM16A (ANO1, DOG1 or TAOS2) has recently been identified as a calcium-activated chloride channel (CaCC) and is reported to be overexpressed in several malignancies; however, its expression and function in colorectal cancer (CRC) remains unclear. In this study, we found expression of TMEM16A mRNA and protein in high-metastatic-potential SW620, HCT116 and LS174T cells, but not in primary HCT8 and SW480 cells, using RT-PCR, western blotting and immunofluorescence labeling. Patch-clamp recordings detected CaCC currents regulated by intracellular Ca2+ and voltage in SW620 cells. Knockdown of TMEM16A by short hairpin RNAs (shRNA) resulted in the suppression of growth, migration and invasion of SW620 cells as detected by MTT, wound-healing and transwell assays. Mechanistically, TMEM16A depletion was accompanied by the dysregulation of phospho-MEK, phospho-ERK1/2 and cyclin D1 expression. Flow cytometry analysis showed that SW620 cells were inhibited from the G1 to S phase of the cell cycle in the TMEM16A shRNA group compared with the control group. In conclusion, our results indicate that TMEM16A CaCC is involved in growth, migration and invasion of metastatic CRC cells and provide evidence for TMEM16A as a potential drug target for treating metastatic colorectal carcinoma.

Expression Profiling of a Human Thyroid Cell Line Stably Expressing the BRAFV600E Mutation

“…ANO1-induced cell proliferation and tumor growth were accompanied by an CANCER GENOMICS & PROTEOMICS 14: 53-68 (2017) 64 increase in ERK1/2 activation and cyclin D1 induction (32). In lung cancer and colorectal cancer, ANO1 overexpression was related to tumor growth and invasion (33,34). The SERPINE2 gene encodes a member of the serpine protein family that inhibits serine proteases.…”

Copy number gain of 11q13.3 genes associates with pathological stage in hypopharyngeal squamous cell carcinoma

“…All rights reserved. (Britschgi et al, 2013;Bill et al, 2015), but may also directly engage with MAP kinase pathways to promote growth and survival (Duvvuri et al, 2012;Sui et al, 2014). Although it is often reported in association with metastasis and recurrence in translational studies, other studies have reported effects on proliferation and local invasion (Ruiz et al, 2012;Shiwarski et al, 2014;Jia et al, 2015), suggesting the tumourigenic functions of Ano1 may be more complex than a 'grow to go' switch.…”

Role of volume-regulated and calcium-activated anion channels in cell volume homeostasis, cancer and drug resistance

“…A pro-proliferative role of ANO1 is found in most cancer cells investigated 118,[141][142][143][144][145][146] and Stanich and coworkers demonstrated that ANO1 regulates cell proliferation at the G1/S transition in the cell cycle. 147 Other studies, however, show that cell proliferation in certain cell types is unaffected by ANO1, e.g.…”

“…120 ANO1 knockdown resulted in a decreased migratory rate. Although many studies have shown the importance of ANO1 in migration 137,139,141,145,146,156 there are also studies demonstrating that ANO1 might act indirectly. Thus, Ubby et al overexpressed ANO1 in HEK293 cells and measured large ANO1-like currents, but no effect on migration was observed.…”