ANO1-downregulation induced by schisandrathera D: a novel therapeutic target for the treatment of prostate and oral cancers

Abstract

Anoctamin 1 (ANO1), a drug target for various cancers, including prostate and oral cancers, is an intracellular calcium-activated chloride ion channel that plays various physiopathological roles, especially in the induction of cancer growth and metastasis. In this study, we tested a novel compound isolated from Schisandra sphenanthera, known as schisandrathera D, for its inhibitory effect on ANO1. Schisandrathera D dose-dependently suppressed the ANO1 activation-mediated decrease in fluorescence of yellow fluorescent protein; however, it did not affect the adenosine triphosphate-induced increase in the intracellular calcium concentration or forskolin-induced cystic fibrosis transmembrane conductance regulator activity. Specifically, schisandrathera D gradually decreased the levels of ANO1 protein and significantly reduced the cell viability in ANO1-expressing cells when compared to those in ANO1-knockout cells. These effects could be attributed to the fact that schisandrathera D displayed better binding capacity to ANO1 protein than the previously known ANO1 inhibitor, Ani9. Finally, schisandrathera D increased the levels of caspase-3 and cleaved poly (ADP-ribose) polymerase 1, thereby indicating that its anticancer effect is mediated through apoptosis. Thus, this study highlights that schisandrathera D, which reduces ANO1 protein levels, has apoptosis-mediated anticancer effects in prostate and oral cancers, and thus, can be further developed into an anticancer agent.

Discovery of a novel natural compound, vitekwangin B, with ANO1 protein reduction properties and anticancer potential

“…Previous studies have reported that a decrease in ANO1 protein levels can lead to decreased cancer cell viability ( Seo et al, 2017 ; 2021 ; Park et al, 2023 ). To establish whether vitekwangin B decreased ANO1 protein levels, PC3 ANO1-KO cells were generated using the CRISPR-Cas9 system, and ANO1 protein levels in PC9 and CHO cells were verified ( Figures 2A, B ).…”

“…Pharmacological inhibition of ANO1 inhibits the growth of various types of cancer cells ( Seo et al, 2017 ; Seo et al, 2021 ; Park et al, 2023 ). Vitekwangin B was tested to determine whether it inhibited the growth of prostate cancer and NSCLC cells by decreasing ANO1 protein levels ( Figure 4 ).…”

“…As the pharmacological inhibition of ANO1 in various cancer cell types has been reported to cause apoptosis ( Song et al, 2018 ; Park et al, 2023 ), we evaluated the apoptotic effects of vitekwangin B in PC3 and PC9 cells. Vitekwangin B significantly increased caspase-3 activity and PARP-1 cleavage, which represent two hallmarks of apoptosis ( Figures 5A–D ) and increased the sub-G1 population ( Supplementary Figure S2 ).…”