Inhibition of Ca²⁺‐activated chloride channel ANO1 suppresses ovarian cancer through inactivating PI3K/Akt signaling

Abstract

Most common ovarian cancers are epithelial carcinoma in which the etiology for carcinogenesis remains elusive. ANO1/TMEM16A, a member of Ca 2+ -activated Cl − channels (CaCCs), has been demonstrated to promote epithelium-originated cancers and whether it plays a role in the pathogenesis of ovarian cancer is unknown. In our study we found that ANO1 proteins were overexpressed in human epithelial ovarian cancer cells and tissue samples. ANO1 protein upregulation was correlated with the clinical FIGO (International Federation of Gynecology and Obstetrics) staging and poor grade in ovarian cancer tissues. Interestingly, the upregulation of ANO1 gene expression was also detected in the peripheral blood mononuclear cells (PBMCs) from preoperative patients with ovarian tumors, and the down-regulation of ANO1 in the PBMCs from postoperative patients. Silencing of ANO1 inhibited proliferation and invasion of ovarian cancer cells. Mechanistically, ANO1 knockdown attenuated phosphorylation of PI3K/ Akt, and inhibition of PI3K/Akt signaling by specific inhibitor LY294002 resulted in suppression of ovarian cancer cells growth promoted by ANO1 expression. Furthermore, intratumoral injection of ANO1 siRNA suppressed subcutaneous xenograft tumor growth in nude mice implanted with ovarian cancer SKOV3 cells. Taken together, our findings demonstrate that ANO1 overexpression is involved in the pathogenesis of human epithelial ovarian cancer. Inhibition of ANO1 upregulation or inactivating PI3K/Akt signaling may have therapeutic potential for epithelial ovarian cancer, and the detection of ANO1 expression level in PBMCs from patients may also serve as a biomarker for diagnosis and prognosis of epithelial ovarian cancers.

OEsophageal Ion Transport Mechanisms and Significance Under Pathological Conditions

“…Similar results were observed with Ani9, T16A(inh)-A01 and CaCC(inh)-A01 inhibitors, which also reduced PC-3 cell proliferation and induced apoptosis, by a TNF-α-mediated signaling pathway (Song et al, 2018). ANO1 inhibitors have also been shown to be beneficial in ovarian cancer, where administration of LY294002 reduced the growth of cancer cells by inhibiting the PI3K/Akt signaling pathway (Liu et al, 2019). The mechanism of action of ANO1 inhibitors is not yet known, and there is no evidence to date that it has been used in the treatment of inflammatory or cancerous diseases of the oesophagus, but it could be a promising target.…”

Calcium-Activated Chloride Channel ANO1/TMEM16A: Regulation of Expression and Signaling

“…In contrast, ANO1 knockdown resulted in a profound inhibition of AKT phosphorylation in ovarian cancer cell lines SKOV3 and Caov-3 (Liu et al, 2019). Given that ANO1 can mediate CAMKII activation (Britschgi et al, 2013) and that CAMK pathway can activate AKT (Yano et al, 1998), authors postulate that this could be a mechanism for AKT activation by ANO1, but this was not experimentally addressed (Liu et al, 2019). Finally, the data on regulation of the relevant to cell growth and survival nuclear factor-κB (NFκB) transcription factor by ANO1 is also controversial.…”

“…Silencing ANO1 had no effect on AKT phosphorylation induced by EGF in human pancreatic cancer cells , or in urinary bladder carcinoma T24 cells and squamous cell carcinoma SCC-1 cells (Duvvuri et al, 2012) under normal cell culture growth conditions. In contrast, ANO1 knockdown resulted in a profound inhibition of AKT phosphorylation in ovarian cancer cell lines SKOV3 and Caov-3 (Liu et al, 2019). Given that ANO1 can mediate CAMKII activation (Britschgi et al, 2013) and that CAMK pathway can activate AKT (Yano et al, 1998), authors postulate that this could be a mechanism for AKT activation by ANO1, but this was not experimentally addressed (Liu et al, 2019).…”

Detection of ANO1 mRNA in PBMCs is a promising method for GISTs diagnosis

“…ANO1 mRNA has been found to be overexpressed in PBMCs of patients with GISTs, and a decline in ANO1 expression levels following surgery has been reported 27 . Our recent results showed that ANO1 mRNA expression in PBMCs is upregulated in preoperative patients with ovarian cancer and decline of ANO1 mRNA expression is noted post-operation 28 . These observations suggest that detection of ANO1 mRNA expression in PBMCs can be a diagnostic and prognostic method for cancers.…”