Niclosamide Induces Cell Cycle Arrest in G1 Phase in Head and Neck Squamous Cell Carcinoma Through Let-7d/CDC34 Axis

Abstract

Niclosamide is a traditional anti-tapeworm drug that exhibits potent anti-cancer activity. Our previous study showed that niclosamide induces cell cycle arrest in G1 phase. Nevertheless, the underlying mechanism remains unknown. The following study investigated the molecular mechanism through which niclosamide induced G1 arrest in head and neck squamous cell carcinoma (HNSCC) cell lines. The effect of niclosamide on human HNSCC cell line WSU-HN6 and CNE-2Z were analyzed using IncuCyte ZOOMTM assay, flow cytometry (FCM), real-time PCR and western blot. Luciferase assay was conducted to demonstrate the interaction between let-7d (a let-7 family member which functions as a tumor suppressor by regulating cell cycle) and 3′UTR of CDC34 mRNA. Xenografts tumor model was established to evaluate the niclosamide treatment efficacy in vivo. Briefly, an exposure to niclosamide treatment led to an increased let-7d expression and a decreased expression of cell cycle regulator CDC34, finally leading to G1 phase arrest. Moreover, an overexpression of let-7d induced G1 phase arrest and downregulated CDC34, while the knockdown of let-7d partially rescued the niclosamide-induced G1 phase arrest. Luciferase assay confirmed the direct inhibition of CDC34 through the targeting of let-7d. Furthermore, niclosamide markedly inhibited the xenografts growth through up-regulation of let-7d and down-regulation of CDC34. To sum up, our findings suggest that niclosamide induces cell cycle arrest in G1 phase in HNSCC through let-7d/CDC34 axis, which enriches the anti-cancer mechanism of niclosamide.

TMEM16A chloride channel does not drive mucus production

“…It is of relevance to note that mucus synthesis (production) and release (secretion) are controlled by different signalling pathways and that the respective regulators do not entirely correlate in the different airway obstructive pulmonary diseases (Rogers & Barnes, 2006; Fahy & Dickey, 2010). Moreover, the conclusion by previous studies that TMEM16A inhibition improves mucus hypersecretion is strongly based on the use of nonspecific inhibitors (Huang et al, 2012; Lin et al, 2015; Qin et al, 2016; Kondo et al, 2017; Benedetto et al, 2019), which were already shown to act on other chloride channels/transporters, including CFTR (Scott-Ward et al, 2004; Dienna et al, 2007; Benedetto et al, 2017) and other members of the TMEM16 family (Namkung et al, 2011; Wanitchakool et al, 2014; Sirianant et al, 2016) and many, such as niclosamide, were also shown to inhibit cell proliferation (Mazzone et al, 2012; Han et al, 2019).…”

“…Whenever there is inflammation associated to cell proliferation (GCH), MUC5AC production is increased because of enrichment in mucus-producing cells, whereas concomitantly TMEM16A is also up-regulated because of cell proliferation (Fig 8C). As some TMEM16A inhibitors are also inhibitors of cell proliferation (Mazzone et al, 2012; Han et al, 2019), it is very likely that these molecules are reducing mucin levels by inhibiting GCH, albeit through a TMEM16A-independent mechanism.…”

Contribution of Anoctamins to Cell Survival and Cell Death

“…Thus, niclosamide was shown to inhibit nuclear factor kappa B (NF-κB), Wnt/ß-catenin signaling, the IL-6-JAK1-STAT3-pathway, GSK-3 and more [132,133,134,135,136,137,138,139,140]. A recent paper suggests cell cycle arrest by niclosamide, through activation of the Let-7d/CDC34 axis [41]. Notably, blockade of notch signaling inhibits goblet cell metaplasia in asthmatic mice, which could be part of the mechanism how niclosamide inhibits mucus production [128,141,142].…”

Niclosamide inhibits the cell proliferation and enhances the responsiveness of esophageal cancer cells to chemotherapeutic agents

“…Previous studies in oral squamous cell carcinoma (26), adrenocortical carcinoma (8) and head and neck cancer (18) and osteosarcoma (25) revealed that niclosamide could induce G1-phase arrest of the cell cycle. Through flow cytometric analysis using DNA dye PI staining, it was revealed that a high proportion of sub-G1 cells were detected in CE48T and BE3 cells after 10 µM niclosamide treatment for 72 h, while only a small proportion of sub-G1 was detected in CE81T cells.…”

“…The mechanism of niclosamide action is through the inhibition of glucose uptake, oxidative phosphorylation, and anaerobic metabolism in the target worms (7). Except for antiprotozoal function, the antineoplastic effects of niclosamide has been revealed in many human cancer cells, including adrenocortical carcinoma (8), breast (9)(10)(11), colorectal (12,13) and cervical cancer (14), glioblastoma (15), hepatocellular carcinoma (16,17), head and neck (18,19) and lung cancer (20,21), leukemia (22,23), nasopharyngeal cancer (24), osteosarcoma (25), oral squamous cell carcinoma (26,27), ovarian (28)(29)(30), prostate (31)(32)(33), renal (34) and thyroid cancer (35). Niclosamide treatment was reported to induce apoptosis of cancer cells in vitro (7,10,23) and suppress tumor size in animal studies (11,29).…”